REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is related to and claims priority from the following pending patent applications, the disclosure of which is hereby incorporated by reference: 
         [0002]    U.S. Provisional Patent Application No. 60/516,613. 
     
    
     FIELD OF THE INVENTION 
       [0003]    The present invention relates to drug mixing systems generally. 
       BACKGROUND OF THE INVENTION 
       [0004]    The following U.S. Patents and non-U.S. patent publications are believed to represent the current state of the art:
   U.S. Pat. Nos. 6,221,041; 6,715,520; 6,409,708; PCT US02/40596; WO 2004004806; WO 03086529; WO 9819724; WO 03/086530; WO 0035517 and WO 0211794.   
 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention seeks to provide an improved drug mixing system, operative for use with a luer fitted hypodermic syringe, which is particularly useful in handling toxic drugs such as antineoplastic drugs. 
         [0007]    There is thus provided in accordance with a preferred embodiment of the present invention a drug mixing system including at least one receptacle port adaptor adapted to be inserted into a port of a fluid receptacle, at least one vial adaptor adapted for connection to a vial containing a drug and at least one syringe adaptor adapted to be attached to a syringe and to at least one of the at least one receptacle port adaptor and the at least one vial adaptor, the system being characterized in that at least one of the at least one receptacle port adaptor, the at least one syringe adaptor and the at least one vial adaptor being vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form. 
         [0008]    There is also provided in accordance with another preferred embodiment of the present invention a drug mixing system including at least one receptacle port adaptor adapted to be inserted into a port of a fluid receptacle, at least one vial adaptor adapted for connection to a vial containing a drug and at least one syringe adaptor adapted to be attached to a syringe and to at least one of the at least one receptacle port adaptor and the at least one vial adaptor, the system being characterized in that the at least one vial adaptor being vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial. 
         [0009]    Preferably, the drug mixing system also includes a membrane vent operative to vent at least one of the at least one receptacle port adaptor, the at least one syringe adaptor and the at least one vial adaptor to the atmosphere. Additionally, the membrane vent includes a filter. Additionally or alternatively, the membrane vent includes a hydrophobic membrane. 
         [0010]    There is also provided in accordance with another preferred embodiment of the present invention a drug mixing system including at least one receptacle port adaptor adapted to be inserted into a port of a fluid receptacle, at least one vial adaptor adapted for connection to a vial containing a drug and at least one syringe adaptor adapted to be attached to a syringe and to at least one of the at least one receptacle port adaptor and the at least one vial adaptor, the system being characterized in that the at least one syringe adaptor is adapted to be brought into fluid communication and mechanically locked to at least one of the at least one receptacle port adaptor and the at least one vial adaptor in a single step. 
         [0011]    Preferably, at least one of the at least one vial adaptor, the at least one receptacle port adaptor and the at least one syringe adaptor are vented to the atmosphere without permitting potentially harmful contents of the vial to reach the atmosphere. 
         [0012]    Preferably, the drug mixing system also includes a stopcock connected to the at least one vial adaptor and to the at least one receptacle port adaptor. 
         [0013]    There is further provided in accordance with yet another preferred embodiment of the present invention a drug mixing system including at least one receptacle port adaptor adapted to be inserted into a port of a fluid receptacle and at least one vial adaptor adapted for connection to a vial containing a drug and connected to the at least one receptacle port adaptor, the system being characterized in that at least one of the at least one receptacle port adaptor and the at least one vial adaptor is vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial. 
         [0014]    There is even further provided in accordance with still another preferred embodiment of the present invention a drug mixing system including at least one receptacle port adaptor adapted to be inserted into a port of a fluid receptacle and at least one vial adaptor adapted for connection to a vial containing a drug and connected to the at least one receptacle port adaptor, the at least one vial adaptor including a venting and sealing element, operative to allow air into the drug mixing system and adapted to prevent air from escaping from the drug mixing system. 
         [0015]    Preferably, the venting and sealing element includes a hydrophobic membrane and a narrow bore. 
         [0016]    Preferably, the narrow bore is irreversibly filled with liquid upon flow of liquid from the fluid receptacle to the vial, thus preventing air from escaping. 
         [0017]    Alternatively or additionally, the receptacle port adaptor includes an elastomer covered needle and the receptacle port adaptor and the vial adaptor are integrally formed. Alternatively, the receptacle port adaptor includes an elastomer covered needle and the receptacle port adaptor, the syringe adaptor and the vial adaptor are integrally formed. 
         [0018]    Preferably, the at least one vial adaptor also includes a protective vial housing operative to prevent release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form in the event of breakage of the vial. 
         [0019]    In another preferred embodiment, the fluid receptacle includes a spike port and the at least one receptacle port adaptor includes a spike port adaptor. Additionally or alternatively, the fluid receptacle includes a needle port and the at least one receptacle port adaptor includes a needle port adaptor. Additionally, the needle port adaptor includes a needle, the needle being protected by a needle protector. Preferably, the needle protector includes a latex needle cover. 
         [0020]    Preferably, the drug mixing system also includes a vial head adaptor adapted for connection between the vial adaptor and the vial. 
         [0021]    In another preferred embodiment, the at least one receptacle port adaptor and the fluid receptacle are adapted to be connected to an intravenous cannula on a patient via an intravenous infusion set. 
         [0022]    Preferably, the at least one syringe adaptor and the syringe are adapted to be connected to an intravenous cannula on a patient via an intravenous infusion set using an infusion set adaptor. Additionally or alternatively, the syringe adaptor is covered by a syringe cover element. 
         [0023]    There is yet further provided in accordance with another preferred embodiment of the present invention a drug mixing system including at least one drug mixing element including atmospheric venting functionality, characterized in that it prevents potentially harmful drug material from being released to the atmosphere via the venting functionality, the potentially harmful drug material including at least one of solid, liquid, gas and aerosol. 
         [0024]    There is even further provided in accordance with yet another preferred embodiment of the present invention a drug mixing method including attaching a luer fitted hypodermic syringe having a plunger to a syringe adaptor, inserting a receptacle port adaptor into a port in a receptacle containing a fluid, attaching the syringe adaptor, having the syringe attached thereto, to the receptacle port adaptor, retracting the plunger, thereby at least partially filling the syringe with fluid drawn from the receptacle in a manner which ensures that the fluid remains sterile and that a user is not exposed to the fluid, connecting the syringe adaptor having the syringe attached thereto, to a vial adaptor assembly, having a drug containing vial attached thereto, pushing the plunger, thus injecting the fluid contained in the syringe into the drug containing vial, thereby producing a drug solution in the vial and retracting the plunger, thus drawing at least part of the contents of the vial into the syringe, wherein at least one of the receptacle port adaptor, the syringe adaptor and the vial adaptor being vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form. 
         [0025]    There is still further provided in accordance with yet another preferred embodiment of the present invention a drug mixing method including attaching a luer fitted hypodermic syringe having a plunger to a syringe adaptor, inserting a receptacle port adaptor into a port in a receptacle containing a fluid, attaching the syringe adaptor, having the syringe attached thereto, to the receptacle port adaptor, retracting the plunger, thereby at least partially filling the syringe with fluid drawn from the receptacle in a manner which ensures that the fluid remains sterile and that a user is not exposed to the fluid, connecting the syringe adaptor having the syringe attached thereto, to a vial adaptor assembly, having a drug containing vial attached thereto, pushing the plunger, thus injecting the fluid contained in the syringe into the drug containing vial, thereby producing a drug solution in the vial and retracting the plunger, thus drawing at least part of the contents of the vial into the syringe, wherein the syringe adaptor is adapted to be brought into fluid communication and mechanically locked to at least one of the receptacle port adaptor and the vial adaptor in a single step. 
         [0026]    There is yet further provided in accordance with another preferred embodiment of the present invention a drug mixing method including attaching a luer fitted hypodermic syringe having a plunger to a syringe adaptor, inserting a receptacle port adaptor into a port in a receptacle containing a fluid, connecting the syringe adaptor having the syringe attached thereto, to a vial adaptor assembly, having a drug containing vial attached thereto, retracting the plunger, thus drawing at least part of the contents of the vial into the syringe, connecting the syringe adaptor having the syringe attached thereto, to the receptacle port adaptor and pushing the plunger, thus injecting the at least part of the contents of the vial into the receptacle, wherein at least one of the receptacle port adaptor, the syringe adaptor and the vial adaptor is vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form. 
         [0027]    There is still further provided in accordance with yet another preferred embodiment of the present invention a drug mixing method including attaching a luer fitted hypodermic syringe having a plunger to a syringe adaptor, inserting a receptacle port adaptor into a port in a receptacle containing a fluid, connecting the syringe adaptor having the syringe attached thereto, to a vial adaptor assembly, having a drug containing vial attached thereto, retracting the plunger, thus drawing at least part of the contents of the vial into the syringe, connecting the syringe adaptor having the syringe attached thereto, to the receptacle port adaptor and pushing the plunger, thus injecting the at least part of the contents of the vial into the receptacle, wherein the syringe adaptor is adapted to be brought into fluid communication and mechanically locked to at least one of the receptacle port adaptor and the vial adaptor in a single step. 
         [0028]    There is even further provided in accordance with another preferred embodiment of the present invention a drug mixing method including attaching a luer fitted hypodermic syringe having a plunger to a syringe adaptor, connecting the syringe adaptor having the syringe attached thereto, to a vial adaptor assembly, having a drug containing vial attached thereto, retracting the plunger, thus drawing at least part of the contents of the vial into the syringe and pushing the plunger, thus injecting the at least part of the contents of the vial into an infusion line, wherein at least one of the receptacle port adaptor, the syringe adaptor and the vial adaptor is vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form. 
         [0029]    There is still further provided in accordance with yet another preferred embodiment of the present invention a drug mixing method including attaching a luer fitted hypodermic syringe having a plunger to a syringe adaptor, connecting the syringe adaptor having the syringe attached thereto, to a vial adaptor assembly, having a drug containing vial attached thereto, retracting the plunger, thus drawing at least part of the contents of the vial into the syringe and pushing the plunger, thus injecting the at least part of the contents of the vial into an infusion line, wherein the syringe adaptor is adapted to be brought into fluid communication and mechanically locked to at least one of the receptacle port adaptor and the vial adaptor in a single step. 
         [0030]    Preferably, the connecting the syringe adaptor also includes disconnecting the syringe adaptor from the receptacle adaptor prior to the connecting. 
         [0031]    Preferably, the connecting the syringe adaptor having the syringe attached thereto to the receptacle port adaptor also includes disconnecting the syringe adaptor from the vial adaptor prior to the connecting. 
         [0032]    Additionally or alternatively, the connecting the syringe adaptor includes connecting the drug containing vial to a vial head adaptor and connecting the drug containing vial having the vial head adaptor attached thereto to the vial adaptor assembly, prior to the connecting the syringe to the vial adaptor assembly. Alternatively or additionally, the drug mixing method also includes attaching the syringe adaptor, having the syringe containing at least part of the drug solution attached thereto, to the receptacle port adaptor and injecting contents of the syringe into the receptacle. 
         [0033]    There is still further provided in accordance with still another preferred embodiment of the present invention a drug mixing method including inserting a receptacle port adaptor into a port in a receptacle containing a fluid, connecting a drug containing vial to the receptacle port adaptor, transferring at least a portion of the fluid from the receptacle to the drug containing vial, thereby producing a drug solution in the vial and subsequently transferring the drug solution from the vial to the receptacle. 
         [0034]    Preferably, the connecting the drug containing vial includes connecting the drug containing vial to a vial head adaptor prior to the connecting the drug containing vial. Additionally or alternatively, the receptacle port adaptor includes at least one of a spike port adaptor and a needle port adaptor. 
         [0035]    There is yet further provided in accordance with another preferred embodiment of the present invention a vial adaptor adapted for connection to a vial containing a drug and adapted for connection to other elements of a drug mixing system, the vial adaptor including a spike adapted for penetrating the vial, a mechanical lock for locking the vial adaptor to the vial once the spike penetrates the vial and an element operative to vent the interior of the vial to the atmosphere without permitting potentially harmful contents of the vial to reach the atmosphere. 
         [0036]    Preferably, the vial adaptor also includes a membrane vent operative to vent the vial adaptor to the atmosphere. Additionally, the membrane vent includes a filter. Alternatively or additionally, the membrane vent includes a hydrophobic membrane. 
         [0037]    Preferably, the vial adaptor also includes a septum equipped syringe port. Additionally or alternatively, the vial adaptor includes at least one locking element, operative to irreversibly lock the vial adaptor to the vial. Preferably, the at least one locking element includes at least one radially extending portion and at least one transversely extending portion. 
         [0038]    There is further provided in accordance with yet another preferred embodiment of the present invention a vial adaptor adapted for connection to a vial containing a drug and being adapted for connection to other elements of a drug mixing system, the vial adaptor including at least one locking element, operative to irreversibly lock the vial adaptor to the vial. 
         [0039]    Preferably, the at least one locking element includes at least one radially extending portion and at least one transversely extending portion. 
         [0040]    There is still further provided in accordance with another preferred embodiment of the present invention a vial adaptor adapted for connection to a vial containing a drug and being adapted for connection to a fluid transfer device, the vial adaptor being vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form. 
         [0041]    Preferably, the vial adaptor also includes a membrane vent operative to vent the vial adaptor to the atmosphere. Additionally, the membrane vent includes a filter. Alternatively or additionally, the membrane vent includes a hydrophobic membrane. 
         [0042]    There is yet further provided in accordance with still another preferred embodiment of the present invention a syringe adaptor adapted for connection to a syringe and adapted for connection to at least one other element of a drug mixing system, the syringe adaptor including a septa housing, at least two septa enclosed in the septa housing defining a space therebetween and a needle, including a tip located in the space when the syringe adaptor is not connected to the at least one other element. 
         [0043]    Preferably, the septa housing is movable relative to the needle, thereby to expose the tip. Additionally or alternatively, at least a portion of the needle is protected by a needle protector. Additionally, the needle protector includes an elastomeric tubing element. 
         [0044]    There is still further provided in accordance with yet a further preferred embodiment of the present invention a vial head adaptor for use in connecting a vial with a first head circumference to a vial adaptor adapted for use with a vial with a second head circumference, the second head circumference being greater than the first head circumference, the vial head adaptor including at least one locking element. 
         [0045]    Preferably, the at least one locking element includes four locking elements arranged generally at right angles to each other. Additionally, the at least one locking element includes a locking tooth. 
         [0046]    There is even further provided in accordance with still another preferred embodiment of the present invention a receptacle port adaptor for use in a drug mixing system including a housing, a needle located within the housing and adapted to be inserted into a port of a fluid receptacle, a septum located in the housing and a locking mechanism to fix the receptacle port adaptor to the port. 
         [0047]    Preferably, the needle is protected by a needle protector. Additionally, the needle protector includes a latex needle cover. Alternatively or additionally, the needle moves between a protected position and a piercing position. 
         [0048]    There is also provided in accordance with yet another preferred embodiment of the present invention a protective vial housing for use with a drug mixing system including a fluid flow passageway adapted to connect a vial containing a drug to the drug mixing system, the protective vial housing being operative to prevent release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form in the event of breakage of the vial. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0049]    The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: 
           [0050]      FIGS. 1A ,  1 B,  1 C,  1 D,  1 E,  1 F,  1 G,  1 H,  1 I,  1 J,  1 K,  1 L and  1 M are simplified pictorial illustrations of various stages of assembly and typical use of a drug mixing system constructed and operative in accordance with a preferred embodiment of the present invention; 
           [0051]      FIG. 2  is a simplified pictorial illustration of a vial head adaptor element which forms part of the drug mixing system of  FIGS. 1A-1M ; 
           [0052]      FIG. 3  is a sectional illustration taken along section lines III-III in  FIG. 2 ; 
           [0053]      FIG. 4  is a simplified exploded view illustration of a vial adaptor assembly which forms part of the drug mixing system of  FIGS. 1A-1M ; 
           [0054]      FIG. 5  is a simplified assembled pictorial illustration of the vial adaptor assembly of  FIG. 4 ; 
           [0055]      FIGS. 6A and 6B  are sectional illustrations taken along respective section lines VIA-VIA and VIB-VIB in  FIG. 5 ; 
           [0056]      FIG. 7  is a simplified exploded view illustration of a syringe adaptor element which forms part of the drug mixing system of  FIGS. 1A-1M ; 
           [0057]      FIG. 8  is a simplified assembled pictorial illustration of the syringe adaptor element of  FIG. 7 ; 
           [0058]      FIGS. 9A and 9B  are sectional illustrations taken along respective section lines IXA-IXA and IXB-IXB in  FIG. 8 ; 
           [0059]      FIG. 9C  is a sectional illustration of an alternative embodiment of the syringe adaptor element of  FIG. 8 , taken along section lines IXA-IXA in  FIG. 8 . 
           [0060]      FIG. 10  is a simplified pictorial illustration of a spike port adaptor element which forms part of the drug mixing system of  FIGS. 1A-1M ; 
           [0061]      FIGS. 11A and 11B  are sectional illustrations taken along section lines XI-XI in  FIG. 10 , of two different inner structures of the spike port adaptor element; 
           [0062]      FIGS. 12A and 12B  are simplified pictorial illustrations of a needle port adaptor element which forms part of the drug mixing system of  FIGS. 1A-1M ; 
           [0063]      FIGS. 13A and 13B  are sectional illustrations taken along respective section lines XIIIA-XIIIA and XIIIB-XIIIB in  FIG. 12A ; 
           [0064]      FIG. 14  is a simplified pictorial illustration of a syringe protection cover which fours part of the drug mixing system of  FIGS. 1A-1M ; 
           [0065]      FIG. 15  is a sectional illustration taken along section lines XV-XV in  FIG. 14 ; 
           [0066]      FIG. 16  is a simplified pictorial illustration of an injection set adaptor element which forms part of the drug mixing system of  FIGS. 1A-1M ; 
           [0067]      FIG. 17  is a sectional illustration taken along section lines XVII-XVII in  FIG. 16 ; 
           [0068]      FIGS. 18A and 18B  are, respectively, a simplified planar illustration and a simplified sectional illustration of the drug mixing system of  FIG. 1A  during attachment of the vial adaptor, the sectional illustration being taken along lines XVIIIB-XVIIIB in  FIG. 18A ; 
           [0069]      FIGS. 19A and 19B  are, respectively, a top view simplified planar illustration and a simplified sectional illustration of the drug mixing system of  FIG. 1C  during attachment of the syringe adaptor, the sectional illustration being taken along lines XIXB-XIXB in  FIG. 19A ; 
           [0070]      FIGS. 19C and 19D  are respectively, a side view simplified planar illustration and a simplified sectional illustration of the drug mixing system of  FIG. 1C  during attachment of the syringe adaptor, the sectional illustration being taken along lines XIXD-XIXD in  FIG. 19C ; 
           [0071]      FIG. 20  is a partially pictorial partially sectional illustration of the drug mixing system of  FIG. 1D  during attachment of the spike port adaptor element; 
           [0072]      FIG. 21  is a partially pictorial partially sectional illustration of the drug mixing system of  FIG. 1D  during attachment of the needle port adaptor element; 
           [0073]      FIG. 22  is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 20  prior to syringe attachment; 
           [0074]      FIG. 23  is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 20  following syringe attachment; 
           [0075]      FIG. 24  is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 21  prior to syringe attachment; 
           [0076]      FIG. 25  is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 21  following syringe attachment; 
           [0077]      FIG. 26  is a sectional illustration of the drug mixing system of  FIG. 1G  prior to drug dilution; 
           [0078]      FIG. 27  is a sectional illustration of the drug mixing system of  FIG. 1H  following drug dilution; 
           [0079]      FIG. 28  is a sectional illustration of the drug mixing system of  FIGS. 1K and 1L  in a protected, ready for delivery state; 
           [0080]      FIG. 29  is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1M and 28  when ready for injection; 
           [0081]      FIG. 30  is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1M and 20  when ready for injection; 
           [0082]      FIGS. 31A ,  31 B,  31 C,  31 D,  31 E,  31 F,  31 G,  31 H,  31 I,  31 J,  31 K and  31 L are simplified pictorial illustrations of various stages of assembly and typical use of a drug mixing system constructed and operative in accordance with another preferred embodiment of the present invention; 
           [0083]      FIG. 32  is a simplified pictorial illustration of a vial head adaptor element which forms part of the drug mixing system of  FIGS. 31A-31L ; 
           [0084]      FIG. 33  is a sectional illustration taken along section lines XXXIII-XXXIII in  FIG. 32 ; 
           [0085]      FIG. 34  is a simplified pictorial illustration of a spike port adaptor element which forms part of the drug mixing system of  FIGS. 31A-31L ; 
           [0086]      FIG. 35  is a sectional illustration taken along section lines XXXV-XXXV in  FIG. 34 ; 
           [0087]      FIG. 36  is a simplified exploded view illustration of an adaptor assembly which forms part of the drug mixing system of  FIGS. 31A-31L ; 
           [0088]      FIG. 37  is a simplified pictorial illustration of a stopcock element which forms part of the adaptor assembly of  FIG. 36 ; 
           [0089]      FIGS. 38A and 38B  are sectional illustrations taken along respective section lines XXXVIIIA-XXXVIIIA and XXXVIIIB-XXXVIIIB in  FIG. 37 ; 
           [0090]      FIG. 39  is a simplified pictorial illustration of a receptacle adaptor subassembly which forms part of the adaptor assembly of  FIG. 36 ; 
           [0091]      FIGS. 40A and 40B  are sectional illustrations taken along respective section lines XLA-XLA and XLB-XLB in  FIG. 39 ; 
           [0092]      FIG. 41  is a simplified pictorial illustration of a vial adaptor subassembly which forms part of the adaptor assembly of  FIG. 36 ; 
           [0093]      FIGS. 42A and 42B  are sectional illustrations taken along respective section lines XLIIA-XLIIA and XLIIB-XLIIB in  FIG. 41 ; 
           [0094]      FIGS. 43A and 43B  are simplified pictorial illustrations of a housing element which forms part of the adaptor assembly of  FIG. 36  in closed and open orientations, respectively; 
           [0095]      FIG. 44  is a simplified assembled pictorial illustration of the adaptor assembly of  FIG. 36 ; 
           [0096]      FIGS. 45A and 45B  are sectional illustrations taken along respective section lines XVA-XVA and XVB-XVB in  FIG. 44 ; 
           [0097]      FIG. 46  is a sectional illustration of the drug mixing system of  FIG. 31C  during attachment of a syringe to the adaptor assembly of  FIGS. 44-45B ; 
           [0098]      FIG. 47  is a sectional illustration of the drug mixing system of  FIG. 31D  during attachment of the receptacle adaptor element of  FIG. 31B  to the adaptor assembly of  FIG. 46 ; 
           [0099]      FIG. 48  is a sectional illustration of the drug mixing system of  FIG. 31E  during attachment of a vial to the adaptor assembly of  FIG. 47 ; 
           [0100]      FIG. 49  is a sectional illustration of the drug mixing system of  FIGS. 31F and 48  during fluid drawing from a receptacle; 
           [0101]      FIG. 50  is a sectional illustration of the drug mixing system of  FIGS. 31G and 48  during fluid injection into a vial; 
           [0102]      FIG. 51  is a sectional illustration of the drug mixing system of  FIGS. 31I and 48  during fluid drawing from a vial; 
           [0103]      FIG. 52  is a sectional illustration of the drug mixing system of  FIGS. 31J and 48  during fluid injection into a receptacle; 
           [0104]      FIG. 53  is a sectional illustration of the drug mixing system of  FIG. 31L  when ready for storage; 
           [0105]      FIGS. 54A ,  54 B,  54 C,  54 D,  54 E,  54 F,  54 G and  54 H are simplified pictorial illustrations of various stages of assembly and typical use of a drug mixing system constructed and operative in accordance with yet another preferred embodiment of the present invention; 
           [0106]      FIG. 55  is a simplified pictorial illustration of a vial head adaptor element which forms part of the drug mixing system of  FIGS. 54A-54H ; 
           [0107]      FIG. 56  is a sectional illustration taken along section lines LVI-LVI in  FIG. 55 ; 
           [0108]      FIG. 57  is a simplified pictorial illustration of a spike port adaptor element which forms part of the drug mixing system of  FIGS. 54A-54H ; 
           [0109]      FIG. 58  is a sectional illustration taken along section lines LVIII-LVIII in  FIG. 57 ; 
           [0110]      FIG. 59  is a simplified exploded view illustration of an adaptor assembly which forms part of the drug mixing system of  FIGS. 54A-54H ; 
           [0111]      FIG. 60  is a simplified pictorial illustration of ad vial adaptor subassembly which forms part of the adaptor assembly of  FIG. 59 ; 
           [0112]      FIGS. 61A and 61B  are sectional illustrations taken along respective section lines LXIA-LXIA and LXIB-LXIB in  FIG. 60 ; 
           [0113]      FIG. 62  is a simplified pictorial illustration of a receptacle adaptor subassembly which forms part of the adaptor assembly of  FIG. 59 ; 
           [0114]      FIGS. 63A and 63B  are sectional illustrations taken along respective section lines LXIIIA-LXIIIA and LXIIIB-LXIIIB in  FIG. 62 ; 
           [0115]      FIGS. 64A and 64B  are simplified pictorial illustrations of a housing element which forms part of the adaptor assembly of  FIG. 59  in closed and open orientations, respectively; 
           [0116]      FIG. 65  is a simplified assembled pictorial illustration of the adaptor assembly of  FIG. 59 ; 
           [0117]      FIGS. 66A and 66B  are sectional illustrations taken along respective section lines LXVIA-LXVIA and LXVIB-LXVIB in  FIG. 65 ; 
           [0118]      FIGS. 67A and 67B  are sectional illustrations of the drug mixing system of  FIG. 54C  during attachment of a vial to the adaptor assembly of  FIG. 65 ; 
           [0119]      FIG. 68  is a sectional illustration of the drug mixing system of  FIG. 54D-54G  during attachment of the receptacle port adaptor element of  FIG. 54B  to the adaptor assembly of  FIG. 67 ; 
           [0120]      FIG. 69  is a sectional illustration of the drug mixing system of  FIGS. 54H and 68  during disconnection of the receptacle port adaptor element of  FIG. 54B  from the adaptor assembly of  FIG. 67 ; 
           [0121]      FIG. 70  is an exploded view illustration of a drug mixing system which is constructed and operative in accordance with a further preferred embodiment of the present invention; 
           [0122]      FIG. 71  is a simplified pictorial illustration of a vial support element which forms part of the drug mixing system of  FIG. 70 ; 
           [0123]      FIGS. 72A and 72B  are, respectively, a sectional illustration and a pictorial sectional illustration taken along section lines LXXII-LXXII in  FIG. 71 ; 
           [0124]      FIG. 73  is a simplified pictorial illustration of the vial support element of  FIG. 71 , when containing a vial; 
           [0125]      FIG. 74  is a sectional illustration taken along section lines LXXIV-LXIV in  FIG. 73 ; 
           [0126]      FIGS. 75A and 75B  are simplified pictorial illustrations of a vial puncturing cover element which forms part of the vial adaptor subassembly of  FIG. 70 ; 
           [0127]      FIG. 76  is a sectional illustration taken along section lines LXXVI-LXXVI in  FIG. 75A ; 
           [0128]      FIG. 77  is a simplified assembled pictorial illustration of the vial adaptor subassembly of  FIG. 70 ; 
           [0129]      FIG. 78  is a sectional illustration taken along section lines LXXVIII-LXXVIII in  FIG. 77 ; 
           [0130]      FIG. 79  is a pictorial illustration of the vial adaptor assembly of  FIG. 77  when assembled to an adaptor assembly in accordance with a preferred embodiment of the present invention; 
           [0131]      FIG. 80  is a sectional illustration taken along section lines LXXX-LXXX in  FIG. 79 ; 
           [0132]      FIG. 81  is a pictorial illustration taken of the vial adaptor assembly and adaptor assembly of  FIG. 79  when connected to a receptacle port adaptor element and a receptacle in accordance with a preferred embodiment of the present invention; 
           [0133]      FIG. 82  is a sectional illustration taken along section lines LXXXII-LXXXII in  FIG. 81 ; 
           [0134]      FIG. 83  is an exploded view illustration of a drug mixing system which is constructed and operative in accordance with a still further preferred embodiment of the present invention; 
           [0135]      FIG. 84  is a simplified pictorial illustration of a receptacle adaptor housing assembly which forms part of the drug mixing system of  FIG. 83 ; 
           [0136]      FIGS. 85A and 85B  are sectional illustrations taken along section lines LXXXVA-LXXXVA and LXXXVB-LXXXVB in  FIG. 84 ; 
           [0137]      FIG. 86  is a simplified pictorial illustration of a receptacle adaptor needle element which forms part of the drug mixing system of  FIG. 83 ; 
           [0138]      FIGS. 87A and 87B  are sectional illustrations taken along section lines LXXXVIIA-LXXXVIIA and LXXXVIIB-LXXXVIIB in  FIG. 86 ; 
           [0139]      FIG. 88  is a simplified assembled pictorial illustration of the receptacle adaptor subassembly of  FIG. 83 ; 
           [0140]      FIGS. 89A and 89B  are sectional illustrations taken along section lines LXXXIXA-LXXXIXA and LXXXIXB-LXXXIXB in  FIG. 88 ; 
           [0141]      FIG. 90  is a pictorial illustration of the receptacle adaptor subassembly of  FIG. 88  when assembled to a vial adaptor subassembly in accordance with a preferred embodiment of the present invention, prior to connection of a needle to a receptacle port element; 
           [0142]      FIG. 91  is a sectional illustration taken along section lines XCI-XCI in  FIG. 90 ; 
           [0143]      FIG. 92  is a pictorial illustration of the receptacle adaptor subassembly of  FIG. 88  when assembled to a vial adaptor subassembly, following connection of a needle to a receptacle port element; and 
           [0144]      FIG. 93  is a sectional illustration taken along section lines XCIII-XCIII in  FIGS. 92 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0145]    Reference is now made to  FIGS. 1A ,  1 B,  1 C,  1 D,  1 E,  1 F,  1 G,  1 H,  1 I,  1 J,  1 K,  1 L and  1 M which are simplified pictorial illustrations of various stages of assembly and typical use of a drug mixing system constructed and operative in accordance with a preferred embodiment of the present invention. 
         [0146]    As seen in  FIG. 1A , a conventional vial  10 , including a top portion  12  and a neck portion  13 , is pushed into engagement with a vial adaptor assembly  30  which is described hereinbelow with reference to  FIGS. 4-6B . Top portion  12  of vial  10  preferably has a septum  31  sealingly seated therein.  FIGS. 18A-18B  show a sectional view of the drug mixing system at this stage: 
         [0147]    Alternatively, if a small vial  32  is used, small vial  32  is pushed into engagement with a vial head adaptor element  34  which is described hereinbelow with reference to  FIGS. 2-3  as shown in  FIG. 1B , and is then pushed into engagement with vial adaptor assembly  30 . The vials  10  and  32  typically contain a drug in a soluble powder form, in a solution or in other suitable form. 
         [0148]    As shown in  FIG. 1C , a luer fitted hypodermic syringe  40  having a plunger  42  and a luer tip  44  is attached to a syringe adaptor element  50  which is described hereinbelow with reference to  FIGS. 7-9B .  FIGS. 19A-19D  show planar and sectional views of the drug mixing system at this stage. 
         [0149]      FIG. 1D  shows a spike port adaptor element  60 , as described hereinbelow with reference to  FIGS. 10-11 , being inserted into a spike port  61  in a receptacle  62  containing a fluid.  FIG. 20  shows a partially pictorial partially sectional view of the drug mixing system at this stage. Typically, receptacle  62  comprises a bag, and the fluid contained therein is sterile saline solution, water, or any other suitable sterile solution or pure fluid. 
         [0150]    Alternatively, a needle port adaptor element  70 , as described hereinbelow with reference to  FIGS. 12A-13B , is inserted into a needle port  64  in receptacle  62 .  FIG. 21  shows a sectional view of the drug mixing system at this stage. 
         [0151]    It will be appreciated by persons skilled in the art that the assembly steps shown in  FIGS. 1B-1D  may be performed in any suitable sequence. 
         [0152]    As seen in  FIG. 1E , syringe adaptor element  50 , having syringe  40  attached thereto ( FIG. 1C ), is connected to a connection port in either of spike port adaptor element  60  or needle port adaptor element  70  of  FIG. 1D .  FIGS. 22-23  and  24 - 25 , respectively, show partially pictorial partially sectional views of the two alternate orientations of the drug mixing system at this stage. 
         [0153]    Typically, plunger  42  of syringe  40  is fully pushed inward into syringe  40  before syringe adaptor element  50  is connected to either of spike port adaptor element  60  and needle port adaptor element  70 . 
         [0154]    As seen in  FIG. 1F , a user retracts plunger  42  in either of the operative orientations of  FIG. 1E , thus at least partially filling syringe  40  with fluid drawn from receptacle  62 . The fluid flows through the spike port adaptor element  60  or through the needle port adaptor element  70  directly into syringe  40 . This flow of fluid ensures that the fluid remains sterile, and that the user is not exposed to the fluid. Subsequently, the syringe  40  and syringe adaptor element  50  are disconnected from the spike port adaptor element  60  or the needle port adaptor element  70 . The drug mixing system of the present invention also ensures that the user is not exposed to the fluid during disconnection thereof, as explained further hereinbelow. 
         [0155]    The user then connects syringe adaptor element  50 , which is attached to syringe  40 , to the vial adaptor assembly  30  having the vial  10  attached thereto, as shown in  FIG. 1G .  FIG. 26  shows a sectional view of the drug mixing system at this stage. 
         [0156]    When the syringe  40  and vial  10  are connected and fluid can flow therebetween, the user pushes plunger  42  inward, with the vial positioned upright, thus injecting the fluid contained in syringe  40  into vial  10  and dissolving the drug contained therein.  FIG. 27  shows a sectional view of the drug mixing system at this stage. 
         [0157]    As seen in  FIG. 1H , the user then shakes the drug mixing system of  FIG. 1G  to ensure that the drug in vial  10  is fully dissolved and that the resulting solution is homogenous. 
         [0158]    It is appreciated that when vial  10  contains a drug in a pre-dissolved form, the steps described hereinabove with reference to  FIGS. 1E-1H  may be obviated. 
         [0159]    As seen in  FIG. 1I , the user turns the drug mixing system upside clown and retracts plunger  42 , thus drawing at least part of the solution from the vial  10  into syringe  40 . Subsequently, syringe  40  and syringe adaptor element  50  are disconnected from vial  10  and vial adaptor assembly  30 , as shown in  FIG. 1J . At this stage, if some of the drug solution is left in vial  10 , vial  10  and vial adaptor assembly  30 , joined thereto, may be stored in a suitable facility for further use. 
         [0160]    At a next stage, the drug solution contained in syringe  40  is prepared for delivery to a hospital ward for infusion into a patient. As shown in  FIG. 1K , syringe  40  containing the drug solution is connected to spike port adaptor element  60  for transferring the drug into receptacle  62 . Alternatively, syringe  40  may be connected to needle port adaptor element  70 . 
         [0161]    As a further alternative, the user may place a syringe protection cover  80 , which is described hereinbelow with reference to  FIGS. 14-15 , onto the syringe adaptor element  50  which is attached to syringe  40 , prior to delivering it to a hospital ward. 
         [0162]    As seen in  FIG. 1L , the user pushes plunger  42  of syringe  40  inward, thus injecting the drug solution into receptacle  62  and further diluting it prior to infusion into a patient. Alternatively, syringe  40  may be covered by the syringe protection cover  80  and is ready for delivery to the appropriate hospital ward.  FIG. 28  is a sectional view of the drug mixing system at this stage. 
         [0163]    As seen in  FIG. 1M , the receptacle  62  and spike port adaptor element  60  are connected via a standard infusion set  92  such as model IAS which is commercially available from Teva Medical Ltd. of Ashdod, Israel, to a patient&#39;s intravenous cannula. The connection to the spike port adaptor element  60  is performed after the removal of a connection element which is placed at the end of the spike port adaptor element  60 .  FIG. 30  is a sectional view of the drug mixing system at this stage. 
         [0164]    Alternatively, the syringe  40  and syringe adaptor element  50  may be connected via an infusion set adaptor element  90 , which is described hereinbelow with reference to  FIGS. 16-17 , to an infusion set  92  including a port  93  and an intravenous cannula  94  which is placed at the injection site. Before syringe adaptor element  50  is attached to the infusion set adaptor element  90 , the syringe protection cover  80  is removed from the end of the syringe adaptor element  50 .  FIG. 29  shows a partially pictorial partially sectional view of the drug mixing system at this stage. 
         [0165]    The structure of elements of the drug mixing system of  FIGS. 1A-1M  is described hereinbelow with reference to  FIGS. 2-17 . 
         [0166]    Reference is now made to  FIG. 2 , which is a simplified pictorial illustration of a vial head adaptor element  34  which forms part of the drug mixing system of  FIGS. 1A-1M , and to  FIG. 3 , which is a sectional illustration taken along section lines III-III in  FIG. 2 . 
         [0167]    As seen in  FIG. 2 , vial head adaptor element  34  is preferably a side-to-side symmetric integrally formed element, which is preferably injection molded of plastic. 
         [0168]    Vial head adaptor element  20  preferably includes a generally cylindrical main body portion  200  and has a central axis  201 . An inner cylindrical surface  202  of main body portion  200  preferably has four arms  204  extending therefrom, each arm  204  being arranged at generally right angles with respect to its neighboring arms. 
         [0169]    Each of arms  204  terminates at an upper end thereof, in the sense of  FIG. 1B , in an inwardly facing generally triangular tooth  206  having a forwardly facing inclined surface  208  and a bottom-facing engagement surface  210  extending generally perpendicular to aim  204 . 
         [0170]    At bottom surface of vial head adaptor element  34 , there are formed four inwardly protruding surfaces  212 , extending generally perpendicular to inner surface  202  of main body portion  200 . Each of neighboring surfaces  212  is preferably arranged at a generally right angle with respect to its neighboring surfaces  212 . Surfaces  212  and arms  204  are rotationally offset from one another about axis  201 . 
         [0171]    Reference is now made to  FIG. 4 , which is a simplified exploded view illustration of a preferred vial adaptor assembly  30  which forms part of the drug mixing system of  FIGS. 1A-1M , to  FIG. 5 , which is a simplified assembled pictorial illustration of the vial adaptor assembly  30 , and to  FIGS. 6A and 6B , which are sectional illustrations taken along respective section lines VIA-VIA and VIB-VIB in  FIG. 5 . 
         [0172]    As seen in  FIGS. 4-6B , vial adaptor assembly  30  comprises a main body element  302  arranged generally about an axis  303 . Main body element  302  is preferably integrally formed and preferably injection molded of plastic. 
         [0173]    Main body element  302  is preferably side-to-side symmetric about axis  303 , and preferably includes a rear portion  304 , which is generally cylindrical and terminates in a forward wall  306 . Rear portion  304  comprises a forward base section  308 , rearward of which are preferably foisted four tabs  310  each having a rectangular window  312 . Rearward of rectangular windows  312  and on an inner surface  314  of each of tabs  310  there are preferably formed two radially extending inwardly facing protrusions  316  each having an inclined surface. Protrusions  316  preferably terminate at a forward end thereof in an inwardly facing transversely extending protrusion  318 . Rearward of protrusions  316 , each of tabs  310  preferably includes an outwardly tapered portion  320 . 
         [0174]    A hollow vial puncturing spike  322  extends rearwardly from a rearward surface  324  of forward wall  306 , and is surrounded by base section  308  and by tabs  310 . Rearward surface  324  additionally includes a circular cylindrical protrusion  325 , surrounding puncturing spike  322 . Two radially extending bores  326  and  327  extend through vial puncturing spike  322 . 
         [0175]    Forward of forward wall  306  of rear portion  304  there is formed an intermediate portion  328  which is generally rectangular, and includes axial hollow tubular portion  330  which is in fluid flow engagement with bore  327  of vial puncturing spike  322 . 
         [0176]    At a top surface of intermediate portion  328  and slightly recessed with respect thereto there is formed a plastic membrane support surface  332 , having formed thereon a plurality of generally evenly distributed spherical protrusions  334 , which are adapted to support a hydrophobic membrane  336  and prevent it from excessive inflation and from cracking. Membrane  336  is adapted to allow free passage of air into the main body element  302 , but to prevent passage therethrough of liquid and air-borne particles, microorganisms and aerosol. A preferred membrane  336  is Model Versapor R 0.2 Micron which is commercially available from Pall Corporation of New York, U.S.A. Membrane  336  is in fluid flow engagement with vial puncturing spike  322  via bore  326  and via a recess  337  formed in intermediate portion  328 . 
         [0177]    A rim  338  surrounding support surface  332  is adapted to support an optional carbon cloth filter  340  and maintain it in a raised position above and spaced from membrane  336 . Carbon cloth filter  340  is adapted to prevent toxic vapors from escaping from main body element  302 , thus protecting users. A preferred carbon cloth filter  340  is Model No. Zorflex EMI, which is commercially available from Charcoal Cloth International Ltd. of Houghton-le-Spring, England. 
         [0178]    Intermediate portion  328  terminates at a forward end thereof in a generally circular wall  342 . Forward of circular wall  342  there is formed a hollow neck portion  344 , which is in fluid flow engagement with hollow tubular portion  330  and with hollow vial puncturing spike  322 . Hollow neck portion  344  terminates at a forward end thereof in a generally circular wall surface  346 . 
         [0179]    Forward of neck portion  344  there is formed a forward facing portion  348 , which is adapted to sealingly accommodate a generally circular septum  350  on a seat  352  which is located at a forward end of portion  348 . Forward facing portion  348  defines a central bore  354  which communicates between tubular portion  330  and septum  350 . 
         [0180]    Vial adaptor assembly  30  preferably additionally includes a covering element  360  which supports and covers membrane  336  and carbon filter  340 . Covering element  360  is a generally cylindrical, generally side-to-side symmetric, element and is preferably formed with a central opening  362  at a forward end thereof through which forward portion  348  extends. 
         [0181]    A pair of outer side surfaces  364  of covering element  360  are each formed with ribbed grip regions  366 . An inner top surface  368  of covering element  360  is preferably flat, and is adapted to support the top surfaces of membrane  336  and carbon filter  340  and to prevent excessive inflation and cracking thereof. 
         [0182]    It is appreciated that the functionalities of membrane  336  and carbon cloth filter  340 , to allow free passage of air into the drug mixing system while preventing passage thereinto of liquid and air-borne particles, microorganisms and aerosol and preventing toxic vapors from escaping from the drug mixing system, may be incorporated, using similar elements, into any of syringe adaptor element  50 , spike port adaptor element  60  and needle port adaptor element  70 . 
         [0183]    Reference is now made to  FIG. 7 , which is a simplified exploded view illustration of syringe adaptor element  50  which forms part of the drug mixing system of  FIGS. 1A-1M , to  FIG. 8 , which is a simplified assembled pictorial illustration of syringe adaptor element  50  and to  FIGS. 9A ,  9 B and  9 C, which are sectional illustrations taken along respective section lines IXA-IXA and IXB-IXB in  FIG. 8 . 
         [0184]    As seen with particular clarity in  FIG. 7 , syringe adaptor element  50  comprises a housing element  500 , which has seated therein a forward septum  502  and a rearward septum  504 . 
         [0185]    Housing element  500  is preferably an integrally formed cylindrical hollow element made of plastic and is preferably side-to-side, top-to-bottom and forward-rearward symmetrical. 
         [0186]    Preferably, a forward portion  506  of housing element  500  includes a seat  508  for forward septum  502 , and a rear portion  510  of the housing element includes a seat  512  for rearward septum  504 . An intermediate portion  514  of housing element  500  preferably includes on a top and a bottom surface thereof generally rectangular outwardly facing protrusions  516 . 
         [0187]    Septa  502  and  504  are preferably formed to have a generally circular portion  518  with a partially spherical protrusion  520  at one side thereof. 
         [0188]    Surrounding housing element  500  there is formed a body  522 , which defines a main body portion  523 , which is generally cylindrical, preferably side-to-side and top-to-bottom symmetrical, and preferably formed of plastic, and side surfaces  524 . Extending from a forward portion of each of side surfaces  524  is an outwardly protruding arm  526 , defining at an inner facing forward end thereof a generally triangular tooth  527  having a transversely extending rearward facing surface  528  which is adapted to engage a forward facing surface of intermediate portion  514  of housing element  500 . 
         [0189]    Rearward of each of arms  526  there is formed a generally rectangular aperture  529 . Adjacent a rearward portion  530  of housing element  500  there is formed a circumferential protrusion  532 , forward of which is formed an additional circumferential protrusion  534 , having a slightly larger outer circumference than that of protrusion  532 . 
         [0190]    A compression spring  536  is seated within housing element  500 , on a shoulder  538  located between intermediate portion  514  and rear portion  510  of housing element  500 . 
         [0191]    A generally cylindrical rear sealing element  540  is located rearward of housing element  500 . Rear sealing element  540  is preferably side to side symmetric, and is typically formed of plastic. 
         [0192]    Rear sealing element  540  preferably defines a forward cowl  542  terminating at a rearward end thereof in a generally circular wall portion  544 . Forward cowl  542  preferably includes a circumferential recess  546 , which is adapted to engage circumferential protrusion  532  of housing element  500 . A forward facing surface  547  of sealing element  540  is adapted to engage a rearward facing surface of additional circumferential protrusion  534  when the syringe adaptor element  500  is assembled. Wall portion  544  preferably defines a rear spring seat for compression spring  536 . 
         [0193]    A tapered inner portion  548  of rear sealing element  540 , which has a smaller circumference than that of housing element  500 , is preferably therewithin at a rear portion thereof. Inner portion  548  is formed forward of and immediately adjacent to wall portion  544  and lies within compression spring  536 . A radially extending bore  549  is preferably formed in inner portion  548  and a hollow needle  550  is sealingly mounted therein. Inner portion  548  is preferably surrounded by a cylindrical portion  552 , which terminates at a rearward end thereof in wall portion  544  and which also has a circumference which is smaller than that of housing element  500 . 
         [0194]    Needle  550  preferably extends axially within compression spring  536  and through the center of housing element  500  and rearward septum  504 . A sharpened tip of needle  550  is preferably placed between forward septum  502  and rearward septum  504 , thus maintaining the needle inaccessible to a user and to the atmosphere. 
         [0195]    Two generally concave symmetric surfaces  554  forming a nearly complete cylinder, may extend rearwardly of wall portion  544  and preferably surround an inner rearward cylindrical portion  556 , which is adapted to engage the luer tip  44  of luer fitted syringe  40 , defining generally symmetric side-facing tabs  558  at rearward ends thereof. The rear portion of needle  550  preferably extends axially within inner cylindrical portion  556 . 
         [0196]    Referring specifically to  FIG. 9C , which illustrates an alternative embodiment of the syringe adaptor element of  FIG. 8 , it is seen that a needle protector  560 , preferably made of latex, at least partially covers needle  550 , thus protecting it from the surrounding atmosphere. 
         [0197]    Reference is now made to  FIG. 10 , which is a simplified pictorial illustration of spike port adaptor element  60  which forms part of the drug mixing system of  FIGS. 1A-1M  and to  FIGS. 11A and 11B  which are sectional illustrations taken along section lines XI-XI in  FIG. 10 . 
         [0198]    Spike port adaptor element  60  preferably comprises a hollow flexible plastic tube  602  having associated therewith a standard clamp  604 , which is commercially available from various manufacturers, such as Qosina of Italy. 
         [0199]    At a forward end thereof, tube  602  is fitted with a hollow spike element  606  which is preferably side-to-side symmetric and formed of plastic. Spike element  606  is preferably formed of a main body portion  607  which preferably defines at a forward end thereof a spike  608 , having formed therein apertures communicating with two axially extending bores  610  and  612 . Rearward of spike  608 , main body portion  607  defines a generally semi-circular planar protrusion  614  adapted to define the location at which a user grips the spike. 
         [0200]    Alternatively, as seen with particular clarity in  FIG. 11B , main body portion  607  may have formed therein a single aperture, which communicates with a single axially extending bore  615 . 
         [0201]    The interior of tube  602  is in fluid flow communication with bore  612 . A bore  616  formed in a neck portion  618  which preferably extends transversely from main body portion  607  and communicates with bore  610 . Hollow neck portion  618  preferably terminates in a forward facing cylindrical portion  620 , which sealingly accommodates a generally circular septum  622  located on a seat  624  which communicates with bore  616 . 
         [0202]    A sealing assembly  630  is preferably attached to a rear end of tube  602 . Sealing assembly  630  preferably includes at a rearwardmost end thereof a selectably removable tapered sealing section  632 , forward of which there is formed a connecting tube portion  634  which is adapted to connect sealing section  632  to tube  602 . Sealing assembly  630  is adapted to seal tube  602  during use of the drug mixing device, and may be removed from tube  602  when receptacle  62  is connected directly to an infusion set spike for infusion of the fluid contained therein to a patient. 
         [0203]    It is appreciated that the spike connector of connection assembly  630  of spike port adaptor element  60  may optionally be replaced by a luer connector. 
         [0204]    Reference is now made to  FIGS. 12A and 12B , which are simplified pictorial illustrations of needle port adaptor element  70  which forms part of the drug mixing system of  FIGS. 1A-1M  and to  FIGS. 13A and 13B , which are sectional illustrations taken along respective section lines XIIIA-XIIIA and XIIIB-XIIIB in  FIG. 12A . 
         [0205]    Needle port adaptor element  70  preferably comprises a main body element  700  arranged generally about an axis  701 . Main body element  700  is preferably integrally formed and preferably injection molded of plastic. 
         [0206]    Main body element  700  is preferably side-to-side symmetric about axis  701 , and preferably includes a rear portion  702  which is generally cylindrical, terminating in a forward wall portion  704  having a bore  706  extending therethrough. Each of side surfaces  708  of rear portion  702  preferably includes a ribbed engagement surface portion  710 . 
         [0207]    Four axially extending slots  712  extend along rear portion  702 , each slot  712  being arranged at generally right angles with respect to its neighboring slots. Defined between slots  712  at a rearward facing end of rear portion  702  are four outwardly tapering tabs  714 . Each tab  714  includes an inwardly facing generally triangular tooth  715  and terminates in a transversely extending section  716 . Rear portion  702  preferably surrounds a generally cylindrical portion  718 , which extends rearwardly from forward wall portion  704 . 
         [0208]    Forward of wall portion  704  there is formed a neck portion  720 , defining a radially extending bore  722 . A hollow needle  724  is adhesively mounted in bore  722  and extends rearwardly thereof along axis  701 . 
         [0209]    Forward of neck portion  720  there is formed a forward facing cylindrical portion  726 , which sealingly supports a generally circular septum  728  on a seat  730  which is located at a forward end of cylindrical portion  726 . A bore  732  preferably extends radially through forward facing cylindrical portion  726 . Bore  732  is preferably in fluid flow engagement with the interior of hollow needle  724 . 
         [0210]    A generally conical cover element  740  which is generally side-to-side and top-to-bottom symmetric about axis  701  preferably is axially slidable with respect to main body element  700  for selectably surrounding rear portion  702  of main body element  700 . 
         [0211]    A rear portion  742  of cover element  740  is preferably outwardly tapered, and terminates in a transversely extending edge surface  744 . Four outwardly facing radially extending protrusions  746  lie along an outer surface of cover element  740 , each protrusion  746  being arranged at generally right angles with respect to its neighboring protrusions. 
         [0212]    Four outwardly facing generally circumferential protrusions  748  are preferably formed on an outer surface  750  of cover element  740  between protrusions  746  thus defining a grip region. 
         [0213]    At a forward end thereof, an inner surface  751  of cover element  740  includes an inwardly tapered section  752 , which is adapted to slidably engage ribbed engagement surface portion  710  of rear portion  702  of main body element  700 . Four generally rectangular inwardly facing protrusions  754  extend from section  752 , each protrusion  754  being arranged at generally right angles with respect to its neighboring protrusions. Protrusions  754  are adapted to slidably engage slots  712  of rear portion  702  of main body element  700 . 
         [0214]    Reference is now made to  FIG. 14 , which is a simplified pictorial illustration of syringe protection cover  80  which forms part of the drug mixing system of  FIGS. 1A-1M  and to  FIG. 15 , which is a sectional illustration taken along section lines XV-XV in  FIG. 14 . 
         [0215]    Syringe protection cover  80  is preferably integrally formed, and is generally side to side symmetric about an axis  800 . A generally circular locking element  802  is preferably formed at a bottom end of syringe protection cover  80 . 
         [0216]    Locking element  802  preferably includes a flat generally circular base surface  804 , preferably extending along a plane which is perpendicular to axis  800 . Surface  804  is integrally formed with a generally cylindrical portion  806 . Cylindrical portion  806  terminates in a generally circular radially outwardly extending wall portion  808 , which lies in a plane parallel to that defined by surface  804 . Wall portion  808  terminates in a generally cylindrical portion  810 , which generally surrounds cylindrical portion  806 . An elongate tab  812  extends from surface  804  along axis  800 . Reference is now made to  FIG. 16 , which is a simplified pictorial illustration of infusion set adaptor element  90  which forms part of the drug mixing system of  FIGS. 1A-1M  and to  FIG. 17 , which is a sectional illustration taken along section lines XVII-XVII in  FIG. 16 . 
         [0217]    As seen in  FIGS. 16 and 17 , infusion set adaptor element  90  is preferably integrally formed, and preferably is side-to-side symmetric along an axis  901 . 
         [0218]    Infusion set adaptor element  90  preferably includes a forward facing cylindrical portion  902 , which is adapted to surround a generally circular septum  904  which is sealingly mounted onto a seat  906  which is located at a forward end of cylindrical portion  902 . 
         [0219]    A generally cylindrical intermediate portion  908  is formed rearward of cylindrical portion  902 , having an outer circumference which is slightly smaller than that of cylindrical portion  902 . At a rear end thereof, intermediate portion  908  tapers toward a cylindrical neck portion  910 , which has an outer circumference which is smaller than that of intermediate portion  908 . 
         [0220]    An axially extending bore  912  extends through neck portion  910 , intermediate portion  908  and cylindrical portion  902 , thus allowing fluid flow through infusion set adaptor element  90  when the septum  904  is suitably pierced. 
         [0221]    The assembled structure of the drug mixing system at various stages of use thereof is described hereinbelow with reference to  FIGS. 18A-30 . 
         [0222]    Reference is now made to  FIGS. 18A and 18B  which are, respectively, a simplified planar illustration and a simplified sectional illustration of the drug mixing system of  FIG. 1B  during attachment of vial adaptor  30 , the sectional illustration being taken along lines XVIIIB-XVIIIB in.  FIG. 18A . 
         [0223]    As seen with particular clarity in  FIG. 18B , vial puncturing spike  322  of vial adaptor assembly  30  punctures septum  31  located inside top portion  12  of vial  10 , thus enabling fluid flow between the main body of vial  10  and forward facing portion  348  of main body element  302  of vial adaptor assembly  30 . Preferably, puncturing of septum  31  releases any vacuum in vial  10  by entrance of air into vial  10  through carbon filter  340  ( FIGS. 4 and 6B ) and membrane  336  ( FIGS. 4 and 6B ). 
         [0224]    Engagement between vial adaptor assembly  30  and vial  10  is preferably maintained by snap engagement of protrusions  316  and  318  of rear portion  304  of main body element  302  with a neck portion  13  of vial  10 . The engagement of protrusions  316  and  318  with neck portion  13  ensures that vial adaptor assembly  30  is latched onto vial  10  and cannot be removed therefrom. Tabs  310  and outwardly tapered portions  320  generally surround top portion  12  and neck portion  13  of vial  10 . 
         [0225]    Reference is now made to  FIGS. 19A and 19B  and to  FIGS. 19C and 19D  which are, respectively, a top and a side view simplified planar illustration and a simplified sectional illustration of the drug mixing system of  FIG. 1C  during attachment of the syringe adaptor element  50  to syringe  40 , the sectional illustrations being taken along lines XIXB-XIXB in  FIG. 19A  and XIXD-XIXD in  FIG. 19C . 
         [0226]    As seen in  FIGS. 19A-19D , luer  44  of luer fitted hypodermic syringe  40  preferably engages inner rearward cylindrical portion  556  of sealing element  540  of syringe adaptor element  50  and tabs  558  formed thereon, such that needle  550  is in fluid flow engagement with the hollow body of syringe  40 . 
         [0227]    At this stage, the sharpened tip of needle  550  is preferably placed between septa  502  and  504 , and compression spring  536  is relaxed. Preferably, when syringe  40  is connected to syringe adaptor assembly  50 , plunger  42  of syringe  40  is pushed fully inward with respect to the syringe. 
         [0228]    Reference is now made to  FIG. 20 , which is a partially pictorial partially sectional illustration of the drug mixing system of  FIG. 1D  during attachment of spike port adaptor element  60 . 
         [0229]    As seen in  FIG. 20 , spike  608  of spike element  606  of spike port adaptor element  60  is preferably inserted into a spike port  61  of receptacle  62 . At this stage, receptacle  62  and tube  602  are in fluid flow engagement. However, clamp  604  is closed and prevents fluid from flowing out of the receptacle through bore  612  into tube  602 . Additionally, bore  610  is in fluid flow communication with cylindrical portion  620  via bore  616  of neck portion  618 . 
         [0230]    Reference is now made to  FIG. 21 , which is a partially pictorial partially sectional illustration of the drug mixing system of  FIG. 1D  during attachment of needle port adaptor element  70 . 
         [0231]    As seen in  FIG. 21 , needle  724  of needle port adaptor element  70  is preferably inserted into needle port  64  of receptacle  62 . Preferably, teeth  715  of tabs  714  engage port  64  when needle  724  is inserted. Additionally, after needle  724  is inserted, cover element  740  is preferably moved with respect to main body element  700  along ribbed engagement surface portion  710  ( FIG. 13B ). 
         [0232]    The axial displacement of cover element  740  preferably seals and locks the connection between main body element  700  and port  64 , by pressing on tabs  714  and pushing them inward. Displacement of cover element  740  includes a corresponding axial displacement of protrusions  754  with respect to slots  712  of rear portion  702  of main body element  700 . The axial displacement terminates when sections  716  of tabs  714  engage inner surface  751  of cover element  740 . 
         [0233]    At this stage, receptacle  62  is preferably in fluid flow engagement with bore  732  of cylindrical portion  726  via intermediate portion  720  and needle  724 . However, fluid does not flow out of cylindrical portion  726 , as the cylindrical portion is sealed by septum  728 . 
         [0234]    Reference is now made to  FIG. 22 , which is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 20  prior to the attachment of syringe  40  and syringe adaptor element  50  to spike port adaptor element  60 . 
         [0235]    As seen in  FIG. 22 , syringe adaptor element  50  and syringe  40  joined thereto are placed in close proximity to cylindrical portion  620  of spike port adaptor element  60 . It is appreciated that at this stage compression spring  536  is relaxed and the sharpened tip of needle  550  is preferably placed between septa  502  and  504 . Preferably, surfaces  528  of teeth  527  of arms  526  engage forward facing surfaces on either side of intermediate portion  514  of housing element  500 . 
         [0236]    Throughout the engagement process, septum  622  of spike port adaptor element  60  and septum  502  of syringe adaptor element  50  are pushed into touching engagement by the biasing force of spring  536 , thus preventing exposure of the tip of needle  550  to the environment. 
         [0237]    Reference is now made to  FIG. 23 , which is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 20  following the attachment of syringe  40  and syringe adaptor element  50  to spike port adaptor element  60 . 
         [0238]    As seen in  FIG. 23  syringe adaptor element  50  and syringe  40  joined thereto are pushed into engagement with cylindrical portion  620  of spike port adaptor element  60 . 
         [0239]    Preferably, surfaces  528  of teeth  527  of arms  526  snap into engagement with wall portion  618 , thus ensuring that the engagement between syringe adaptor element  50  and cylindrical portion  620  is secure. At this stage, spring  536  is in a compressed state, and housing element  500  is pushed rearwardly by the pressure from cylindrical portion  620 . 
         [0240]    The rearward motion of housing element  500  causes the sharpened tip of needle  550  to pierce septa  502  and  622 . As a result, needle  550  partially extends through the hollow space in cylindrical portion  620 , and is in fluid flow engagement with receptacle  62  via bore  610  of spike  608  of spiked element  606  and via bore  616  of neck portion  618 . Due to the fluid flow engagement between luer  44  of syringe  40  and needle  550  of syringe adaptor element  50 , the syringe  40  is now in fluid flow engagement with receptacle  62 . It is appreciated that when using the syringe adaptor element described in  FIG. 9C , needle protector  560  at least partially collapses, thus exposing the needle  550 . 
         [0241]    In order to draw fluid from receptacle  62  into syringe  40  via spiked element  606 , bore  616  of neck portion  618 , cylindrical portion  620  and needle  550 , a user retracts plunger  42 . In order to disengage syringe adaptor element  50  and cylindrical portion  620 , a user pushes slightly on arms  526  extending from side surfaces  524  of housing element  522 , causing teeth  527  to move outward and release a rearward facing surface of cylindrical portion  620 , thus disconnecting the cylindrical portion. 
         [0242]    Throughout the disengagement process, septum  622  of spike port adaptor element  60  and septum  502  of syringe adaptor element  50  are pushed into touching engagement by the biasing force of spring  536 , thus preventing exposure of the tip of needle  550  to the environment. 
         [0243]    Reference is now made to  FIG. 24 , which is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 21  prior to the attachment of syringe  40  and syringe adaptor element  50  to needle port adaptor element  70 . As seen in  FIG. 24 , syringe adaptor element  50  and syringe  40  joined thereto are placed in close proximity to cylindrical portion  726  of needle port adaptor element  70 . It is appreciated that at this stage compression spring  536  is relaxed and the sharpened tip of needle  550  is preferably located between septa  502  and  504 . Preferably, surfaces  528  of teeth  527  of arms  526  engage forward facing surfaces on either side of intermediate portion  514  of housing element  500 . 
         [0244]    Reference is now made to  FIG. 25 , which is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1E and 21  following the attachment of syringe  40  and syringe adaptor element  50  to needle port adaptor element  70 . As seen in  FIG. 25  syringe adaptor element  50  and syringe  40  joined thereto are pushed into engagement with cylindrical portion  726  of needle port adaptor element  70 . 
         [0245]    Preferably, surfaces  528  of teeth  527  of arms  526  snap to engage a rearward facing wall portion of cylindrical portion  726 , thus ensuring that the engagement between syringe adaptor element  50  and cylindrical portion  726  is secure. At this stage, spring  536  is in a compressed state, and housing element  500  is pushed rearwardly by the pressure from cylindrical portion  726 . 
         [0246]    The rearward motion of housing element  500  causes the sharpened tip of needle  550  to pierce septa  502  and  728 . As a result, needle  550  partially extends through bore  732  of cylindrical portion  726 , and is in fluid flow engagement with receptacle  62  via needle  724  of rear portion  702 , neck portion  720  of main body element  700  and bore  732  of cylindrical portion  726 . Due to the fluid flow engagement between luer  44  of syringe  40  and needle  550  of syringe adaptor element  50 , the syringe  40  is now in fluid flow engagement with receptacle  62 . It is appreciated that when using the syringe adaptor element described in  FIG. 9C , needle protector  560  at least partially collapses, thus exposing the needle  550 . 
         [0247]    In order to draw fluid from receptacle  62  into syringe  40  via needle  724 , bore  732  and needle  550 , a user retracts plunger  42 . In order to disengage syringe adaptor element  50  and cylindrical portion  726 , a user pushes slightly on arms  526  extending from side surfaces  524  of housing element  522 , causing teeth  527  to move outward and release a rearward facing wall portion of cylindrical portion  726 , thus disconnecting cylindrical portion  726 . 
         [0248]    Throughout the engagement and disengagement process, septum  728  of needle port adaptor element  70  and septum  502  of syringe adaptor element  50  are pushed into touching engagement by the biasing force of spring  536 , thus preventing exposure of the tip of needle  550  to the environment. 
         [0249]    Reference is now made to  FIG. 26 , which is a sectional illustration of the drug mixing system of  FIG. 1G  prior to drug dilution. 
         [0250]    As seen in  FIG. 26 , syringe adaptor element  50  and syringe  40  joined thereto are placed in close proximity to forward facing portion  348  of vial adaptor element  30 . 
         [0251]    It is appreciated that at this stage compression spring  536  is relaxed and the sharpened tip of needle  550  is preferably located between septa  502  and  504 . Preferably, surfaces  528  of teeth  527  of arms  526  engage forward facing surfaces on either side of intermediate portion  514  of housing element  500 . 
         [0252]    At this stage, syringe  40  is preferably filled with a fluid drawn from receptacle  62  ( FIGS. 22-25 ) and therefore plunger  42  is at least partially retracted. 
         [0253]    Reference is now made to  FIG. 27 , which is a sectional illustration of the drug mixing system of  FIG. 1H  following drug dilution. 
         [0254]    As seen in  FIG. 27  syringe adaptor element  50  and syringe  40  joined thereto are pushed into engagement with forward facing portion  348  of vial adaptor element  30 . 
         [0255]    Preferably, surfaces  528  of teeth  527  of arms  526  snap to engage wall portion  346  of forward facing portion  348 , thus ensuring that the engagement between syringe adaptor element  50  and portion  348  is secure. At this stage, spring  536  is in a compressed state, and housing element  500  is pushed rearwardly by the pressure from forward facing portion  348 . 
         [0256]    The rearward motion of housing element  500  causes the sharpened tip of needle  550  to pierce septa  502  and  350 . As a result, needle  550  partially extends through a hollow section of portion  348 , and is in fluid flow engagement with vial  10  via bore  350  of neck portion  344  and vial puncturing spike  322  of main body element  302 . Due to the fluid flow engagement between luer  44  of syringe  40  and needle  550  of syringe adaptor element  50 , the syringe  40  is now in fluid flow engagement with vial  10 . It is appreciated that when using the syringe adaptor element described in  FIG. 9C , needle protector  560  at least partially collapses, thus exposing the needle  550 . 
         [0257]    At this stage, a user injects the fluid contained in syringe  40  into vial  10  via bore  350  of neck portion  344  and vial puncturing spike  322  by inwardly pushing plunger  42  of syringe  40 . A corresponding volume of air escapes from vial  10  via membrane  336  and optional carbon cloth filter  340 . It is appreciated that any drug containing aerosol is blocked by the membrane and any non-aerosolized drug vapor is adsorbed by the charcoal filter, thus protecting users and the environment from contamination. 
         [0258]    Preferably, the user ensures that the drug contained in vial  10  is fully dissolved, and then draws at least part of the drug solution contained in vial  10  into syringe  40  by turning the system upside down and retracting plunger  42  (not shown). At this stage, a corresponding volume of sterile air enters vial  10  via membrane  336  and optional carbon cloth filter  340 . 
         [0259]    In order to disengage syringe adaptor element  50  and forward facing portion  348 , a user pushes slightly on arms  526  extending from side surfaces  524  of housing element  522 , causing teeth  527  to move outward and release a wall portion  346  of forward facing portion  348 , thus disconnecting the forward facing portion. 
         [0260]    Throughout the engagement and disengagement process, septum  350  of vial adaptor element  30  and septum  502  of syringe adaptor element  50  are pushed into touching engagement by the biasing force of spring  536 , thus preventing exposure of the tip of needle  550  to the environment. 
         [0261]    Reference is now made to  FIG. 28 , which is a sectional illustration of the drug mixing system of  FIGS. 1K and 1L  in a protected, ready for delivery state, when syringe adaptor element  50  is covered by syringe protection cover  80 . 
         [0262]    As seen in  FIG. 28 , syringe adaptor element  50  is preferably covered at a forward end thereof by syringe protection cover  80 . At this stage, plunger  42  is preferably at least partially retracted with respect to syringe  40 , and the syringe contains a drug solution withdrawn from vial  10  ( FIG. 27 ). 
         [0263]    The forwardmost circumference of main body portion  523  is preferably seated in the recess formed by wall portions  806  and  810  of syringe protection cover  80  and surface  804  of syringe cover element  80  preferably engages a forward surface of septum  502 . 
         [0264]    It is appreciated that at this stage compression spring  536  is relaxed and the sharpened tip of needle  550  is preferably located between septa  502  and  504 . Preferably, surfaces  528  of teeth  527  of arms  526  engage forward facing surfaces on either side of intermediate portion  514  of housing element  500 . 
         [0265]    Reference is now made to  FIG. 29 , which is a partially pictorial, partially sectional illustration of the drug mixing system of  FIGS. 1M and 28  when ready for injection. 
         [0266]    As seen in  FIG. 29 , syringe protection cover  80  has been removed from syringe adaptor element  50 , and syringe adaptor element  50  and syringe  40  joined thereto are pushed into engagement with cylindrical portion  902  of infusion set adaptor element  90 , while the infusion set adaptor element  90  is connected to a side port of an intravenous cannula located at an injection site. 
         [0267]    Preferably, surfaces  528  of teeth  527  of arms  526  snap to engage a rearward facing wall portion of cylindrical portion  902 , thus ensuring that the engagement between syringe adaptor element  50  and cylindrical portion  902  is secure. At this stage, spring  536  is in a compressed state, and housing element  500  is pushed rearwardly by the pressure from cylindrical portion  902 . 
         [0268]    The rearward motion of housing element  500  causes the sharpened tip of needle  550  to pierce septa  502  and  904 . As a result, needle  550  partially extends through bore  912  of infusion set adaptor element  90 , and is therefore in fluid flow engagement with the injection site. Due to the fluid flow engagement between luer  44  of syringe  40  and needle  550  of syringe adaptor element  50 , the syringe  40  is now in fluid flow engagement with the injection site. It is appreciated that when using the syringe adaptor element described in  FIG. 9C , needle protector  560  at least partially collapses, thus exposing the needle  550 . 
         [0269]    In order to disengage syringe adaptor element  50  and cylindrical portion  902 , a user pushes slightly on arms  526  extending from side surfaces  524  of housing element  522 , causing teeth  527  to move outward and release a the rearward facing wall portion of cylindrical portion  902 , thus disconnecting the cylindrical portion. 
         [0270]    Reference is now made to  FIG. 30 , which is a partially pictorial partially sectional illustration of the drug mixing system of  FIGS. 1M and 20  when ready for injection. 
         [0271]    Preferably, receptacle  62  is connected via spike port adaptor element  60  to an infusion set  92 . The infusion set then connects to a standard intravenous cannula  94  such as a Venolit model commercially available from Teva Medical Ltd. of Ashdod, Israel which is located in an infusion site. Typically, prior to connection of spike port adaptor element  60  to infusion set  92 , sealing element  630  is removed, and infusion set  92  is connected directly to tube  602 . 
         [0272]    Alternatively, infusion set  92  may be connected to a new receptacle, not containing a drug, in which case the drug solution is injected directly into the infusion set. If this option is selected, syringe adaptor  50  having syringe  40  ( FIG. 28 ) joined thereto is connected to port  93  after syringe protector cover  80  is removed, and the drug solution contained therein is injected into the infusion line. 
         [0273]    Preferably, surfaces  528  of teeth  527  of arms  526  snap to engage a rearward facing wall portion of port  93 , thus ensuring that the engagement between syringe adaptor element  50  and port  93  is secure. At this stage, spring  536  is in a compressed state, and housing element  500  is pushed rearwardly by the pressure from port  93 . 
         [0274]    The rearward motion of housing element  500  causes the sharpened tip of needle  550  to pierce septum  502  and a sealing septum of port  93 . As a result, needle  550  partially extends into infusion set  92 , and is therefore in fluid flow engagement with the injection site. Due to the fluid flow engagement between luer  44  of syringe  40  and needle  550  of syringe adaptor element  50 , the syringe  40  is now in fluid flow engagement with the injection site. 
         [0275]    In order to disengage syringe adaptor element  50  and port  93 , a user pushes slightly on arms  526  extending from side surfaces  524  of housing element  522 , causing teeth  527  to move outward and release a rearward facing wall portion of port  93 , thus disconnecting the port. 
         [0276]    Reference is now made to  FIGS. 31A ,  31 B,  31 C,  31 D,  31 E,  31 F,  31 G,  31 H,  31 I,  31 J and  31 L which are simplified pictorial illustrations of various stages of assembly and typical use of a drug mixing system constructed and operative in accordance with another preferred embodiment of the present invention. 
         [0277]      FIG. 31A  shows a spike port adaptor element  1030 , as described hereinbelow with reference to  FIGS. 34-35 , being inserted into a spike port  1031  in a receptacle  1032  containing a fluid. Preferably, a luer connector of spike port adaptor element  1030  is sealed by a luer cover element  1034 . 
         [0278]    Typically, receptacle  1032  comprises a bag, and the fluid contained therein is sterile salt solution, water, or any other suitable sterile solution or pure fluid. 
         [0279]    As shown in  FIG. 31B , a luer-equipped hypodermic syringe  1040 , having a plunger  1042  and a luer tip  1044 , is connected to a syringe port of an adaptor assembly  1050 , which is described hereinbelow with reference to FIGS.  36  and  44 - 45 B. Preferably, the syringe port is defined by a stopcock  1052  which is described hereinbelow with reference to  FIGS. 37-38B  and includes a removable protection cap  1054 .  FIG. 46  shows a sectional view of the drug mixing system at this stage. 
         [0280]    Typically, plunger  1042  of syringe  1040  is pushed fully inward before the syringe is connected to the syringe port of stopcock  1052 . 
         [0281]      FIG. 31C  shows spike port adaptor element  1030  and receptacle  1032  joined thereto being connected to a receptacle adaptor subassembly  1056  of adaptor assembly  1050 . Subassembly  1056  is described hereinbelow with reference to  FIGS. 39-40B . Preferably, stopcock  1052  is in an operative orientation which enables fluid flow between receptacle adaptor subassembly  1056  and syringe  1040 .  FIG. 47  shows a sectional view of the drug mixing system at this stage. 
         [0282]    As seen in  FIG. 31D , a vial  1060 , including a top portion  1062  and a neck portion  1063 , is pushed into engagement with a vial adaptor subassembly  1058  of adaptor assembly  1050 . Top portion  1062  of vial  1060  preferably has a septum  1064  sealingly seated therein. Subassembly  1058  is described hereinbelow with reference to  FIGS. 41-42B . 
         [0283]    Alternatively, if a small vial  1066  is used, small vial  1066  is pushed into engagement with a vial head adaptor element  1068 , which is described hereinbelow with reference to  FIGS. 32-33 , as shown in  FIG. 31E , and is then pushed into engagement with vial adaptor subassembly  1058 . Vials  1060  and  1066  typically contain a drug in soluble powder form, in a solution or in other suitable four.  FIG. 48  shows a sectional view of the drug mixing system at this stage. 
         [0284]    It is appreciated that stopcock  1052 , receptacle adaptor subassembly  1056  and vial adaptor subassembly  1058  are preferably enclosed in a housing element  1070  of adaptor assembly  1050 , which is described hereinbelow with reference to  FIGS. 43A-43B . 
         [0285]    It will be appreciated by persons skilled in the art that the assembly steps shown in  FIGS. 31C-31E  may be performed in any suitable sequence. 
         [0286]    As seen in  FIG. 31F , a user retracts plunger  1042  while receptacle  1032  is upright and vial  1060  lies therebelow, thus at least partially filling syringe  1040  with fluid drawn from receptacle  1032 . The operative orientation of stopcock  1052  enables this fluid flow from receptacle  1032  to syringe  1040  via spike port adaptor element  1030 , receptacle adaptor subassembly  1056  and stopcock  1052  in a manner that ensures that the fluid remains sterile, and that the user is not exposed thereto.  FIG. 49  shows a sectional view of the drug mixing system at this stage. 
         [0287]    The user then rotates a handle  1080  of stopcock  1052  to enable fluid flow between syringe  1040  and vial adaptor subassembly  1058 , having joined thereto vial  1060 , as shown in  FIG. 31G . 
         [0288]    When the syringe  1040  and vial  1060  are in fluid flow engagement, the user pushes plunger  1042  inward, thus injecting the fluid contained in syringe  1040  into vial  1060  and dissolving the drug contained therein.  FIG. 50  shows a sectional view of the drug mixing system at this stage. 
         [0289]    As seen in  FIG. 31H , the user then shakes the drug mixing system of  FIG. 31G  to ensure that the drug in vial  1060  is fully dissolved and that the resulting solution is homogenous. 
         [0290]    As seen in  FIG. 31I , the user turns the system upside down, so that the vial  1060  faces upward, and then retracts plunger  1042 , thus drawing at least part of the solution from vial  1060  into syringe  1040 .  FIG. 51  shows a sectional view of the drug mixing system at this stage. 
         [0291]    It will be appreciated by those skilled in the art that at this stage the drug mixing system of the present invention is preferably held such that vial  1060  lies above syringe  1040 , to allow smooth flow of the fluid from vial  1060  to syringe  1040  via vial adaptor subassembly  1058  and stopcock  1052 . 
         [0292]    As shown in  FIG. 31J , handle  1080  of stopcock  1052  is oriented to enable flow of fluid between syringe  1040  and receptacle  1032 . The user then pushes plunger  1042  of syringe  1040  inward, thus injecting the drug solution into receptacle  1032  and further diluting it prior to infusion into a patient.  FIG. 52  shows a sectional view of the drug mixing system at this stage. 
         [0293]    Subsequently, spike port adaptor element  1030 , having receptacle  1032  joined thereto, is disconnected from adaptor assembly  1050 , which remains connected to vial  1060  as shown in  FIG. 31K . 
         [0294]    As seen in  FIG. 31L , if some of the drug solution is left in vial  1060 , vial  1060  and adaptor assembly  1050  joined thereto may be stored in a suitable facility for further use. It is appreciated that at this stage syringe  1040  remains connected to the syringe port of stopcock  1052  of adaptor assembly  1050 .  FIG. 53  is a sectional view of the drug mixing system at this stage. 
         [0295]    The structure of elements of the drug mixing system of  FIGS. 31A-31L  is described hereinbelow with reference to  FIGS. 32-43B . 
         [0296]    Reference is now made to  FIG. 32 , which is a simplified pictorial illustration of a vial head adaptor element  1068  which forms part of the drug mixing system of  FIGS. 31A-31L  and to  FIG. 33  which is a sectional illustration taken along section lines XXXIII-XXXIII in  FIG. 32 . 
         [0297]    As seen in  FIG. 32 , vial head adaptor element  1068  is preferably a side-to-side symmetric integrally formed element which is preferably injection molded of plastic. 
         [0298]    Vial head adaptor element  1068  preferably includes a main body portion  1200  which is generally cylindrical and has a central axis  1201 . An inner cylindrical surface  1202  of main body portion  1200  preferably has four arms  1204  extending therefrom, each arm  1204  being arranged at generally right angles with respect to its neighboring arms. 
         [0299]    Each of arms  1204  terminates at an upper end thereof, in the sense of  FIG. 31A , in an inwardly facing generally triangular tooth  1206  having a upwardly facing inclined surface  1208  and a bottom-facing engagement surface  1210  extending generally perpendicular to arm  1204 . 
         [0300]    At the bottom of vial head adaptor element  1068 , there are formed four inwardly protruding surfaces  1212 , extending generally perpendicular to inner surface  1202  of main body portion  1200 . Each of neighboring surfaces  1212  is preferably arranged at a generally right angle with respect to its neighboring surfaces  1212 . Surfaces  1212  and arms  1204  are rotationally offset from one another about axis  1201 . 
         [0301]    Reference is now made to  FIG. 34 , which is a simplified pictorial illustration of spike port adaptor element  1030  which forms part of the drug mixing system of  FIGS. 31A-31L  and to  FIG. 35  which is a sectional illustration taken along section lines XXXV-XXXV in  FIG. 34 . 
         [0302]    Spike port adaptor element  1030  preferably comprises a hollow flexible plastic tube  1302  having associated therewith a standard clamp  1304 , which is commercially available from various manufacturers such as Quosina of Italy. 
         [0303]    At a forward end thereof, tube  1302  is connected to a tube port  1305  of a hollow spike element  1306  which is preferably formed of plastic. Spike element  1306  preferably includes a main body portion  1307  which defines at a forward end thereof a spike  1308  which includes an aperture communicating with an axially extending bore  1310  and an additional bore  1312  which extends partially through main body portion  1307  and communicates with a top portion of bore  1310 , thus facilitating complete priming before drug injection. 
         [0304]    Rearward of spike  1308 , main body portion  1307  defines a generally circular planar protrusion  1314  adapted to define the location at which a user grips the spike. 
         [0305]    The interior of tube  1302  is in fluid flow communication with bore  1312  via tube port  1305 . Bore  1310  preferably terminates in an aperture located in spike  1308  of main body portion  1307 , and fully extends through the body portion  1307 . 
         [0306]    Main body portion  1307  preferably terminates in a connection port  1318  which is adapted to connect spike port adaptor element  1030  to receptacle adaptor subassembly  1056 . Connection port  1318  preferably sealingly accommodates a generally circular septum  1320  on a seat  1322 . Septum  1320  preferably engages the rear end of bore  1310 , thus sealing the rear end of the bore. 
         [0307]    Forward of connection port  1318 , there is formed on main body portion  1307  a circumferential protrusion  1324 , forward of which is formed an additional circumferential protrusion  1326 , having an outer circumference which is slightly larger than that of protrusion  1324 . Protrusions  1324  and  1326  are adapted to limit the movement of spike port adaptor element  1030  when it is connected to receptacle adaptor subassembly  1056 . 
         [0308]    A luer connector  1330  is preferably attached to a rear end of tube  1302 . Luer connector  1330  preferably includes at a rearwardmost end thereof a narrow hollow port section  1332 , forward of which there is formed a connecting tube portion  1334  and a hollow neck portion  1336  which connects port section  1330  to tube  1302 . Preferably, luer connector  1330  is sealed by luer cover element  1034 . 
         [0309]    It is appreciated that spike port adaptor element  1030  may alternatively be identical to spike port adaptor element  630  described hereinabove with reference to  FIGS. 10-11B . 
         [0310]    Reference is now made to  FIG. 36 , which is a simplified exploded view illustration of adaptor assembly  1050  which forms part of the drug mixing system of  FIGS. 31A-31L . 
         [0311]    As seen with particular clarity in  FIG. 36 , adaptor assembly  1050  includes vial adaptor subassembly  1058 , onto which is placed a hydrophobic membrane  1402 , above which is optionally seated a carbon cloth filter  1404 . Vial adaptor subassembly  1058  is connected at a forward portion thereof to a vial port  1082  of stopcock  1052 , which additionally includes a syringe port  1084  adapted for engagement with luer  1044  of syringe  1040 . Stopcock  1052  additionally includes a receptacle port  1086  which is adapted for connection to a rear connection element  1406  of receptacle adaptor subassembly  1056 . 
         [0312]    Preferably, when syringe  1040  is not connected to the syringe port of stopcock  1052 , the syringe port  1084  is sealed by protection cap  1054 . 
         [0313]    A needle holding element  1408  is preferably seated within rear connection element  1406  and supports a needle  1410 . A forward portion of needle  1410  is preferably protected by a flexible latex needle protection element  1412 . Receptacle adaptor subassembly  1056  connects at a rearward end thereof to rear connection element  1406 , enclosing needle holding element  1408 , needle  1410  and needle protection element  1412 . 
         [0314]    The forward portion of vial adaptor subassembly  1058  as well as stopcock  1052  and the rear portion of receptacle adaptor subassembly  1056  are located within housing element  1070 . However, a handle  1080  of stopcock  1052  protrudes from housing element  1070 , thus enabling a user to change the operative orientation of the stopcock  1052  and thereby switch the fluid flow pathway. 
         [0315]    Reference is now made to  FIG. 37 , which is a simplified pictorial illustration of stopcock  1052  which forms part of the adaptor assembly of  FIG. 36  and to  FIGS. 38A and 38B , which are sectional illustrations taken along respective section lines XXXVIIIA-XXXVIIIA and XXXVIIIB-XXXVIIIB in  FIG. 37 . 
         [0316]    Stopcock  1052 , as noted hereinabove, has a vial port  1082 , a syringe port  1084  and a receptacle port  1086 , all of which are defined in a housing portion  1090 . User operable handle  1080  is fixed to a pathway defining element  1092 , which defines a three-way direction pathway, as seen with particularity in  FIG. 38B . Selectable rotational orientation of handle  1080  enables any two of ports  1082 ,  1084  and  1086  to be placed in mutual fluid communication. Stopcock  1052  is commercially available from Elcam Ltd. of Baram, Israel. 
         [0317]    Reference is now made to  FIG. 39 , which is a simplified pictorial illustration of receptacle adaptor subassembly  1056  which forms part of the adaptor assembly of  FIG. 36  and to  FIGS. 40A and 40B , which are sectional illustrations taken along respective section lines XLA-XLA and XLB-XLB in  FIG. 39 . 
         [0318]    As seen in  FIGS. 39-40B , receptacle adaptor subassembly  1056  includes a main body element  1600  which is arranged generally about an axis  1601 . Main body element  1600  is preferably integrally formed of plastic, and is preferably side-to-side symmetric about axis  1601 . Main body element  1600  preferably includes a generally cylindrical base portion  1602  terminating in a rear portion  1604 . 
         [0319]    Top and bottom generally concave wall portions  1606  are formed at a forward end of base portion  1602 , each wall portion  1606  defining on an outer surface thereof an outwardly facing axially extending rib  1608 , which extends from a forwardmost end of each of wall portions  1606  and along base portion  1602 . 
         [0320]    A connection surface  1610  extending transversely from side surfaces  1612  of base portion  1602  connects an outwardly extending arm  1614  to each side surface  1612 . 
         [0321]    Each arm  1614  preferably has a generally square rear portion  1616 , formed rearwardly of connection surface  1610 , and has a radially extending outwardly facing protrusion  1618  formed thereon. Protrusion  1618  preferably extends onto an outer surface of a generally rectangular forward portion  1620  of each of arms  1614 , which extends forwardly of connection surface  1610 . 
         [0322]    An inwardly facing generally triangular tooth  1622  is formed adjacent a top end of each of forward portions  1620 . Each tooth  1622  preferably includes a forwardly facing inclined surface  1624  and a rearwardly facing engagement surface  1626 . 
         [0323]    Rear portion  1604  preferably includes a transversely extending generally circular portion  1630  which forms a base for ribs  1608  and which terminates at a rear end thereof in an axially extending generally cylindrical wall portion  1632 . 
         [0324]    Wall portion  1632  preferably defines on a top and bottom surface thereof a small generally rectangular window  1634 , and two forwardly facing slots  1636  which are formed on either side of window  1634 . Two generally symmetric side-facing tabs  1638  are formed on side surfaces  1640  of wall portion  1632 , each tab  1638  being formed forwardly of a generally rectangular forwardly facing slot  1642 . 
         [0325]    Rear connection element  1406  preferably includes a forward disk  1652  defining a central bore  1654 . Disk  1652  preferably functions as a terminating wall for a forward facing cylindrical portion  1656 . Rearward of disk  1652  there is preferably formed a rear portion  1658 , having a narrow bore  1660  extend therethrough. Bore  1660  preferably widens toward the rear end of rear portion  1658 , thus enabling rear portion  1658  to connect to an appropriate port. Preferably, two generally symmetric tabs  1662  are formed on top and bottom surfaces of rear portion  1658 . Cylindrical portion  1656  preferably has an outer circumference that is slightly smaller than that of wall portion  1632 , and is located therein. 
         [0326]    Needle holding element  1408  preferably supports needle  1410  on a generally circular disk portion  1672 . Needle  1410  extends axially through base portion  1602  of main body element  1600  and through bore  1660  of rear connection element  1650 . Disk portion  1672  is preferably seated in cylindrical portion  1656 , and is locked into cylindrical portion  1656  by portion  1630 . 
         [0327]    Reference is now made to  FIG. 41 , which is a simplified pictorial illustration of vial adaptor subassembly  1058  which forms part of adaptor assembly  1050  of  FIG. 36  and to  FIGS. 42A and 42B , which are sectional illustrations taken along respective section lines XLIIA-XLIIA and XLIIB-XLIIB in  FIG. 41 . 
         [0328]    As seen in  FIGS. 41-42B , vial adaptor subassembly  1058  comprises a main body element  1702  arranged generally about an axis  1703 . Main body element  1702  is preferably integrally formed and preferably injection molded of plastic. 
         [0329]    Main body element  1702  is preferably side-to-side symmetric about axis  1703 , and preferably includes a rear portion  1704 , which is generally cylindrical and terminates in a forward wall  1706 . Rear portion  1704  comprises a forward base section  1708 , preferably having four transversely extending outwardly facing protrusions  1709  extend therefrom, each protrusion being arranged at generally right angles with respect to its neighboring protrusions. 
         [0330]    Rearward of base section  1708  there are formed four tabs  1710  each having a rectangular window  1712 . Rearward of rectangular windows  1712  and on an inner surface  1714  of each of tabs  1710  there are preferably formed two radially extending inwardly facing protrusions  1716  each having an inclined surface. Protrusions  1716  preferably terminate at a forward end thereof in an inwardly facing transversely extending protrusion  1718 . Rearward of protrusions  1716 , each of tabs  1710  preferably includes an outwardly tapered portion  1720 . 
         [0331]    A hollow vial puncturing spike  1722  extends rearwardly from a rearward surface  1724  of forward wall  1706 , and is surrounded by base section  1708  and by tabs  1710 . Rearward surface  1724  additionally includes a circular cylindrical protrusion  1725 , surrounding puncturing spike  1722 . Two axially extending bores  1726  and  1727  extend through vial puncturing spike  1722 . 
         [0332]    Forward of forward wall  1706  of rear portion  1704  there is formed an intermediate portion which is formed of two generally rectangular surfaces  1728 , and which includes an axial tubular portion  1730  having a bore  1731  extend therethrough, bore  1731  being in fluid flow engagement with bore  1726  of hollow vial puncturing spike  1722 . 
         [0333]    On the top rectangular surface  1728  and slightly recessed with respect thereto there is formed a plastic membrane support surface  1732 , having formed thereon a plurality of generally evenly distributed spherical protrusions  1734 , which are adapted to support hydrophobic membrane  1402  and prevent it from excessive inflation and from cracking. Membrane  1402  is adapted to allow free passage of air to and from main body element  1702 , but to prevent passage of liquid and air borne particles, microorganisms and aerosol. A preferred membrane  1402  is Model Versapor R 0.2 Micron which is commercially available from Pall Corporation of New York, U.S.A. Membrane  1402  is in fluid flow engagement with vial puncturing spike via bore  1727  and via a recess  1737  formed in top rectangular surface  1728 . 
         [0334]    A rim  1738  surrounding support surface  1732  is adapted to support a carbon cloth filter  1404  and maintain it in a raised position above and spaced from membrane  1402 . Carbon filter  1404  is adapted to prevent toxic vapors from escaping from main body element  1702 , thus protecting users. A preferred carbon cloth filter  1404  is Model No. Zorflex EMI which is commercially available from Charcoal Cloth International Ltd. of Houghton-le-Spring, England. 
         [0335]    Rectangular surfaces  1728  of the intermediate portion terminate at a forward end thereof in a forward facing cylindrical portion  1748 , having a bore  1750  extend therethrough. Preferably, bore  1750  is a continuation of tubular portion  1730  of the intermediate portion. 
         [0336]    It is appreciated that the functionalities of membrane  1402  and carbon cloth filter  1404 , to allow free passage of air into the drug mixing system while preventing passage thereinto of liquid and air-borne particles, microorganisms and aerosol and preventing toxic vapors from escaping from the drug mixing system, may be incorporated, using similar elements, into spike port adaptor element  1030  or receptacle adaptor subassembly  1056 . 
         [0337]    Reference is now made to  FIGS. 43A and 43B , which are simplified pictorial illustrations of the housing element  1070  which forms part of the adaptor assembly  1050  of  FIG. 36  in closed and open orientations, respectively. 
         [0338]    As seen in  FIGS. 43A and 43B , housing element  1070  is preferably integrally formed about an axis  1800  and includes a top housing portion  1801  and a bottom housing portion  1802 . Preferably, housing portions  1801  and  1802  are side-to-side symmetric about axis  1800 . Preferably, each of housing portions  1801  and  1802  includes a semi-cylindrical forward portion  1804  and a semi-cylindrical rearward portion  1806 . 
         [0339]    Top housing portion  1801  includes an inwardly recessed portion  1808  including a generally round aperture  1810  which extends forwardly into an elongate aperture  1812 . Rearward of aperture  1810  there is preferably formed an elongate protrusion  1814 . Preferably, apertures  1810  and  1812  lie below handle  1080  of stopcock  1052  when adaptor assembly  1050  is assembled. 
         [0340]    Bottom housing portion  1802  includes an inwardly recessed portion  1816  which is generally symmetrical to recessed portion  1808  of top housing portion  1801 , and which includes a central generally round aperture  1818 . Two elongate protrusions  1820  are formed on either side of aperture  1818 , such that rearward protrusion  1820  is generally symmetrical to protrusion  1814  of top housing portion  1801 . Preferably, a bottom portion of pathway defining element  1090  of stopcock  1052  extends through aperture  1818  when adaptor assembly  1050  is assembled. 
         [0341]    Top housing portion  1801  includes at forward and rearward ends thereof outwardly extending fingers  1822  terminating in a generally triangular teeth  1824  which include inclined outwardly facing surfaces  1826  and engagement surfaces  1828 . Bottom housing portion  1802  preferably includes at forward and rearward ends thereof two generally rectangular windows  1830  which are placed generally below fingers  1822  and are adapted to engage engagement surfaces  1828  of fingers  1822  when housing element  1070  is assembled. 
         [0342]    An inner surface  1834  of housing element  1070  preferably includes at a rearward end thereof a circumferential recess  1836  which is adapted to engage protrusions  1709  of rear portion  1704  of vial adaptor subassembly  1058 . An outer surface of housing element  1070  which lies above recess  1836  preferably includes an outwardly facing protrusion  1840  which protrudes out of cylindrical forward portion  1804 . 
         [0343]    Preferably, side surfaces of top housing portion  1801  and bottom housing portion  1802  include generally parallel generally rectangular slots  1842 , through which syringe port  1084  of stopcock  1052  extends when adaptor assembly  1050  is assembled. 
         [0344]    Reference is now made to  FIG. 44 , which is a simplified assembled pictorial illustration of the adaptor assembly of  FIG. 36  and to  FIGS. 45A and 45B , which are sectional illustrations taken along respective section lines XLVA-XLVA and XLVB-XLVB in  FIG. 44 . 
         [0345]    As seen in  FIGS. 44-45B , rear portion  1704  of vial adaptor subassembly  1058  extends from a rear portion of housing element  1070 . Vial puncturing spike  1722  preferably extends out of housing element  1070 , and is accessible for connection of vial  1060  or of vial  1066  ( FIG. 31E ) thereto. 
         [0346]    Preferably, circumferential recess  1836  of inner surface  1834  of housing element  1070  engages protrusions  1709  of rear portion  1704  of vial adaptor subassembly  1058 . Preferably, forward facing cylindrical portion  1748  engages vial port  1082  of stopcock  1052 . 
         [0347]    A forward portion of main body element  1600  of receptacle adaptor subassembly  1056  preferably extends from a forward portion of housing element  1070  of adaptor assembly  1050 , and surrounds needle  1410  enclosed in needle protection element  1412 . Main body element including needle  1410  and needle protection cover  1412  is preferably accessible for connection of spike port adaptor element  1030  ( FIGS. 34-35 ) thereto. 
         [0348]    Preferably, rear portion  1658  of rear connection element  1406  engages receptacle port  1086  of stopcock  1052 . A rear end of needle  1410  at least partially extends through bore  1660  such that needle  1410  is in fluid flow communication with receptacle port  1086 . 
         [0349]    Syringe port  1084  of stopcock  1052  preferably extends from housing element  1070  through slots  1842  formed in side surfaces thereof. Preferably, pathway defining element  1092  extends from apertures  1810  and  1812  of top housing portion  1801 , and a bottom portion of stopcock  1052  extends through aperture  1818  of bottom housing element. 
         [0350]    Housing element  1070  is preferably assembled such that top housing portion  1801  and bottom housing portion  1802  are connected by engagement of engagement surfaces  1828  of teeth  1824  of top housing portion  1801  and windows  1830  of bottom housing portion  1802 . 
         [0351]    Reference is now made to  FIG. 46 , which is a sectional illustration of the drug mixing system of  FIG. 31B  during attachment of syringe  1040  to the adaptor assembly  1050  of  FIGS. 44-45B . 
         [0352]    As seen in  FIG. 46 , luer tip  1044  of syringe  1040  is attached to syringe port  1084  of stopcock  1052 . At this stage, handle  1080  of stopcock  1052  is positioned such that fluid can flow from receptacle port  1086  to syringe  1040  thereof. It is appreciated that at this stage plunger  1042  of syringe  1040  is preferably pushed fully inward in the syringe. 
         [0353]    Reference is now made to  FIG. 47 , which is a sectional illustration of the drug mixing system of  FIG. 31C  during attachment of spike port adaptor element  1030  and receptacle  1032  of  FIG. 31A  to the receptacle adaptor subassembly  1056  of the adaptor assembly  1050  of  FIG. 46 . 
         [0354]    As seen in  FIG. 47 , spike port adaptor element  1030 , having receptacle  1032  joined thereto, is connected to receptacle adaptor subassembly  1056  of adaptor assembly  1050 . 
         [0355]    Spike  1308  is preferably previously inserted into spike port  1031  of receptacle  1032 , such that bore  1310  of spike element  1306  engages fluid content of receptacle  1032 . Connection port  1318  of spike port adaptor element  1030  engages wall portions  1606  and base portion  1602  of main body element  1600  of receptacle adaptor subassembly  1056 . 
         [0356]    Connection port  1318  is preferably locked into connection with receptacle adaptor subassembly  1056  by engagement of engagement surfaces  1626  of forward portions  1620  of arms  1614  ( FIG. 40B ) and a rearward facing wall portion of connection port  1318 . 
         [0357]    Preferably, needle  1410  punctures needle protection cover  1412  and septum  1320 , resulting in a change to the structure of the needle protection cover. At this stage, receptacle  1032  is in fluid flow communication with syringe  1040  via bore  1310  of spike  1308  of spike port adaptor element  1030 , needle  1410 , bore  1660  and receptacle port and syringe port  1084  of stopcock  1052 . 
         [0358]    Reference is now made to  FIG. 48 , which is a sectional illustration of the drug mixing system of  FIG. 31D  during attachment of vial  1060  to vial adaptor subassembly  1058  of the adaptor assembly  1050  of  FIG. 47 . 
         [0359]    Vial  1066  and vial head adaptor element  1068  joined thereto ( FIG. 31E ) or vial  1060  is preferably pushed into engagement with vial puncturing spike  1722  of vial adaptor subassembly  1058 . 
         [0360]    Typically, vial puncturing spike  1722  of vial adaptor subassembly  1058  punctures septum  1064  located inside top portion  1062  of vial  1060 , thus enabling fluid flow between the main body of vial  1060  and cylindrical portion  1748  of main body element  1702  of vial adaptor subassembly  1058 . Preferably, puncturing of septum  1064  releases any vacuum in vial  1060  by entrance of air into vial  1060  through carbon filter  1404  ( FIG. 42B ) and membrane  1402  ( FIG. 42B ). 
         [0361]    Engagement between vial adaptor subassembly  1058  and vial  1060  is preferably maintained by snap engagement of protrusions  1716  and  1718  ( FIGS. 42A and 42B ) of rear portion  1704  of main body element  1702  with a neck portion  1063  of vial  1060 . The engagement of protrusions  1716  and  1718  with neck portion  1063  ensures that vial adaptor subassembly  1058  is latched onto vial  1060  and cannot be removed therefrom. Tabs  1710  and outwardly tapered portions  1720  generally surround top portion  1062  and neck portion  1063  of vial  1060 . 
         [0362]    At this stage, the main body of vial  1060  is in fluid flow communication with syringe port  1084  via vial puncturing spike  1722 , bore  1750  of cylindrical portion  1748  and vial port  1082  of stopcock  1052 . 
         [0363]    Reference is now made to  FIG. 49 , which is a sectional illustration of the drug mixing system of  FIGS. 31F and 48  during fluid drawing from receptacle  1032  into syringe  1040 . 
         [0364]    At this stage, plunger  1042  of syringe  1040  is preferably retracted, thus drawing fluid from receptacle  1032  into syringe  1040 . Fluid drawn from receptacle  1032  reaches syringe  1040  via bore  1310  of spike  1308  of spike port adaptor element  1030 , needle  1410 , bore  1660  of receptacle adaptor subassembly  1056 , receptacle port  1086 , pathway defining element  1092 , syringe port  1084  and luer tip  1044 . 
         [0365]    Reference is now made to  FIG. 50 , which is a sectional illustration of the drug mixing system of  FIGS. 31G and 48  during injection of fluid from syringe  1040  into vial  1060 . 
         [0366]    Initially, the user rotates handle  1080  of stopcock  1052 , thus bringing syringe port  1084  into fluid flow engagement with vial port  1082 . 
         [0367]    Preferably, the user pushes plunger  1042  of syringe  1040  inwardly with respect to syringe  1040 , resulting in injection of fluid from syringe  1040  to vial  1060 , thus dissolving the drug contained in the vial. The fluid injected from syringe  1040  flows to vial  1060  via luer tip  1044  of syringe  1040 , syringe port  1084 , pathway defining element  1092 , vial port  1082 , bore  1750  of cylindrical portion  1748  and vial puncturing spike  1722 . 
         [0368]    The user preferably shakes the drug mixing system of  FIG. 50  as shown in  FIG. 31H , in order to ensure that the drug contained in vial  1060  is fully dissolved, and that the drug solution is homogenous. 
         [0369]    Reference is now made to  FIG. 51 , which is a sectional illustration of the drug mixing system of  FIGS. 31I and 48  during drawing of fluid from vial  1060  into syringe  1040 . 
         [0370]    At this stage, the user positions the system such that vial  1060  is on top, and preferably draws at least part of the drug solution contained in vial  1060 , by at least partially retracting plunger  1042  of syringe  1040 . The fluid drawn from vial  1060  flows into syringe  1040  via vial puncturing spike  1722 , bore  1750  of cylindrical portion  1748 , vial port  1082 , pathway defining element  1092  and syringe port  1084  of stopcock  1052  and luer tip  1044  of syringe  1040 . 
         [0371]    Reference is now made to  FIG. 52 , which is a sectional illustration of the drug mixing system of  FIGS. 31J and 48  during injection of fluid from syringe  1040  into receptacle  1032 . 
         [0372]    At a first stage, the user rotates handle  1080  of stopcock  1052 , resulting in syringe port  1084  being in fluid flow engagement with vial port  1082 . 
         [0373]    Subsequently, plunger  1042  of syringe  1040  is preferably pushed inward with respect to the main body portion of the syringe. The inward displacement of plunger  1042  causes injection of fluid from syringe  1040  into receptacle  1032 . Fluid drawn from syringe  1040  reaches receptacle  1032  via luer tip  1044 , syringe port  1084 , pathway defining element  1092 , receptacle port  1086  of stopcock  1052 , bore  1660  of receptacle adaptor subassembly  1056 , needle  1410  and bore  1310  of spike  1308  of spike port adaptor element  1030 . 
         [0374]    Reference is now made to  FIG. 53 , which is a sectional illustration of the drug mixing system of  FIG. 31L  when ready for storage. 
         [0375]    As shown in  FIG. 53 , spike port adaptor element  1030  ( FIGS. 34-35 ) and receptacle  1032  joined thereto are disconnected from receptacle adaptor subassembly  1056  of adaptor assembly  1050 . Typically, spike port adaptor element  1030  is disconnected from receptacle adaptor subassembly  1056  by slightly pushing arms  1614  extending from side surfaces  1612  ( FIGS. 39-40B ) of base portion  1602 , causing teeth  1620  to move outward and release the rearward facing wall portion of connection port  1318  ( FIGS. 34-35 ), thus disconnecting the connection port. Typically, needle  1410  is released from connection port  1318 , and needle protection cover  1412  is deployed and once again fully encloses needle  1410 , thus preventing liquid spill and aerosol spray. 
         [0376]    Adaptor assembly  1050 , including vial adaptor subassembly  1058 , stopcock  1052 , receptacle adaptor subassembly  1056  and housing element  1070 , is preferably stored in a suitable cooling facility. During cooling thereof, adaptor assembly is preferably connected to syringe  1040 , having plunger  1042  fully pushed inward, and to vial  1060  containing a drug solution therein. Typically, pathway defining element  1092  of stopcock  1052  connects receptacle port  1086  to syringe port  1084  at this stage. 
         [0377]    Reference is now made to  FIGS. 54A ,  54 B,  54 C,  54 D,  54 E,  54 F,  54 G and  54 H which are simplified pictorial illustrations of various stages of assembly and typical use of a drug mixing system constructed and operative in accordance with yet another preferred embodiment of the present invention. 
         [0378]      FIG. 54A  shows a spike port adaptor element  2010 , as described hereinbelow with reference to  FIGS. 57-58 , being inserted into a spike port  2011  in a receptacle  2012  containing a fluid. Preferably, a luer connector of spike port adaptor element  2010  is sealed by a luer cover element  2014 . 
         [0379]    Typically, receptacle  2012  comprises a bag, and the fluid contained therein is sterile salt solution, water, or any other suitable sterile solution or pure fluid. 
         [0380]    As seen in  FIG. 54B , a vial  2020 , including a top portion  2022  and a neck portion  2023 , is pushed into engagement with a vial adaptor subassembly  2044  of adaptor assembly  2040 . Top portion  2022  of vial  2020  preferably has a septum  2024  sealingly seated therein. Subassembly  2044  is described hereinbelow with reference to  FIGS. 60-61B . 
         [0381]    Alternatively, if a small vial  2026  is used, small vial  2026  is pushed into engagement with a vial head adaptor element  2030  which is described hereinbelow with reference to  FIGS. 55-56  as shown in  FIG. 54C , and is then pushed into engagement with vial adaptor subassembly  2044 . Vials  2020  and  2026  typically contain a drug in soluble powder form, in a solution or in other suitable form.  FIGS. 67A and 67B  show a sectional view of the drug mixing system at this stage. 
         [0382]      FIG. 54D  shows spike port adaptor element  2010  and receptacle  2012  joined thereto, being connected to a receptacle adaptor subassembly  2046  of adaptor assembly  2040 , which is described hereinbelow with reference to  FIGS. 62-63B . 
         [0383]    It is appreciated that receptacle adaptor subassembly  2046  and vial adaptor subassembly  2044  are preferably enclosed in a housing element  2050  of adaptor assembly  2040 , which is described hereinbelow with reference to  FIGS. 64A-64B . 
         [0384]    It is appreciated by persons skilled in the art that the assembly steps shown in  FIGS. 54A-54D  may be performed in any suitable sequence. 
         [0385]    As seen in  FIG. 54E , a user holds receptacle  2012  upright and squeezes the receptacle, thus at least partially filling vial  2020  with fluid squeezed out of receptacle  2012 . This flow of fluid ensures that the fluid remains sterile, and that the user is not exposed thereto. 
         [0386]    As seen in  FIG. 54F , the user then shakes the drug mixing system of  FIG. 54E  to ensure that the drug in vial  2020  is fully dissolved and that the resulting solution is homogenous. 
         [0387]    As seen in  FIG. 54G , the user reverses the direction of the receptacle  2012 , such that it is now facing downward, and then squeezes the receptacle. Squeezing of the receptacle  2012  causes the drug solution contained in vial  2020  to be drawn into the receptacle, thus further diluting the solution. The user preferably repeats this action until vial  2020  is empty, thus diluting the entire content of the vial in a single receptacle. 
         [0388]    As shown in  FIG. 54H , spiked receptacle adaptor element  2010  having receptacle  2012  joined thereto is disconnected from adaptor assembly  2040 , which remains connected to vial  2020 . It is appreciated that at this stage adaptor assembly  2040  and vial  2020  may be disposed of. 
         [0389]    The structure of elements of the drug mixing system of  FIGS. 54A-54H  is described hereinbelow with reference to  FIGS. 55-64B . 
         [0390]    Reference is now made to  FIG. 55 , which is a simplified pictorial illustration of a vial head adaptor element  2030  which forms part of the drug mixing system of  FIGS. 54A-54H  and to  FIG. 56  which is a sectional illustration taken along section lines LVI-LVI in  FIG. 55 . 
         [0391]    As seen in  FIG. 55 , vial head adaptor element  2030  is preferably a side-to-side symmetric integrally formed element which is preferably injection molded of plastic. 
         [0392]    Vial head adaptor element  2030  preferably includes a main body portion  2200  which is generally cylindrical and has a central axis  2201 . An inner cylindrical surface  2202  of main body portion  2200  preferably has four arms  2204  extending therefrom, each arm  2204  being arranged at generally right angles with respect to its neighboring arms. 
         [0393]    Each of arms  2204  terminates at an upper end thereof, in the sense of  FIG. 54C , in an inwardly facing generally triangular tooth  2206  having a forwardly facing inclined surface  2208  and a bottom-facing engagement surface  2210  extending generally perpendicular to arm  2204 . 
         [0394]    At bottom surface of vial head adaptor element  2030 , there are formed four inwardly protruding surfaces  2212 , extending generally perpendicular to inner surface  2202  of main body portion  2200 . Each of neighboring surfaces  2212  is preferably arranged at a generally right angle with respect to its neighboring surfaces  2212 . Surfaces  2212  and arms  2204  are rotationally offset from one another about axis  2201 . 
         [0395]    Reference is now made to  FIG. 57 , which is a simplified pictorial illustration of spike port adaptor element  2030  which forms part of the drug mixing system of  FIGS. 54A-54H  and to  FIG. 58  which is a sectional illustration taken along section lines LVIII-LVIII in  FIG. 57 . 
         [0396]    Spike port adaptor element  2010  preferably comprises a hollow flexible plastic tube  2302  having associated therewith a standard clamp  2304 , which is commercially available from various manufacturers, such as Qosina of Italy. 
         [0397]    At a forward end thereof, tube  2302  is connected to a tube port  2305  of a hollow spike element  2306  which is preferably formed of plastic. Spike element  2306  is preferably formed of a main body portion  2307  which preferably defines at a forward end thereof a spike  2308 , having formed therein an aperture communicating with an axially extending bore  2310  and an additional bore  2312  which extends partially through main body portion  2307  and communicates with a top portion of bore  2310 . 
         [0398]    Rearward of spike  2308 , main body portion  2307  defines a generally circular planar protrusion  2314  adapted to define the location at which a user grips the spike. 
         [0399]    The interior of tube  2302  is in fluid flow communication with bore  2312  via tube port  2305 . Bore  2310  preferably terminates in an aperture located in spike  2308  of main body portion  2307  and fully extends through the main body portion. 
         [0400]    Main body portion  2307  preferably terminates in a connection port  2318  which is adapted to connect spike port adaptor element  2010  to receptacle adaptor subassembly  2046 . Connection port  2318  preferably sealingly accommodates a generally circular septum  2320  on a seat  2322 . Septum  2320  preferably engages the rear end of bore  2310 , thus sealing the rear end of the bore. 
         [0401]    Forward of connection port  2318 , there is formed on main body portion  2307  a circumferential protrusion  2324 , forward of which is formed an additional circumferential protrusion  2326 , having an outer circumference which is slightly larger than that of protrusion  2324 . Protrusions  2324  and  2326  are adapted to limit the movement of spike port adaptor element  2010  when it is connected to receptacle adaptor subassembly  2044 . 
         [0402]    A luer connector  2330  is preferably attached to a rear end of tube  2302 . Luer connector  2330  preferably includes at a rearwardmost end thereof a narrow hollow port section  2332 , forward of which there is formed a connecting tube portion  2334  and a hollow neck portion  2336  which is adapted to connect luer connector  2330  to tube  2302 . Preferably, luer connector  2330  is sealed by luer cover element  2014 . 
         [0403]    It is appreciated that spike port adaptor element  2010  may alternatively be identical to spike port adaptor element  630  described hereinabove with reference to  FIGS. 10-11B . 
         [0404]    Reference is now made to  FIG. 59 , which is a simplified exploded view illustration of adaptor assembly  2040  which forms part of the drug mixing system of  FIGS. 54A-54H . 
         [0405]    As seen with particular clarity in  FIG. 59 , adaptor assembly  2040  comprises vial adaptor subassembly  2044 , onto which are placed a hydrophobic membrane  2402 , above which is optionally seated a carbon cloth filter  2404 . Vial adaptor subassembly  2044  is connected at a forward portion thereof to a rear connection element  2406  of receptacle adaptor subassembly  2046 . 
         [0406]    A needle holding element  2408  is preferably seated within rear connection element  2406  and supports a needle  2410 . A forward portion of needle  2410  is preferably protected by a flexible latex needle protection element  2412 . Receptacle adaptor subassembly  2046  connects at a rearward end thereof to rear connection element  2406 , enclosing needle holding element  2408  and needle protection element  2412 . 
         [0407]    The forward portion of vial adaptor subassembly  2044  as well as the rear portion of receptacle adaptor subassembly  2046  are located within housing element  2050 . 
         [0408]    Reference is now made to  FIG. 60 , which is a simplified pictorial illustration of vial adaptor subassembly  2044  which forms part of adaptor assembly  2040  of  FIG. 59  and to  FIGS. 61A and 61B , which are sectional illustrations taken along respective section lines LXIA-LXIA and LXIB-LXIB in  FIG. 60 . 
         [0409]    As seen in  FIGS. 60-61B , vial adaptor subassembly  2044  comprises a main body element  2502  arranged generally about an axis  2503 . Main body element  2502  is preferably integrally formed and preferably injection molded of plastic. 
         [0410]    Main body element  2502  is preferably side-to-side symmetric about axis  2503 , and preferably includes a rear portion  2504 , which is generally cylindrical and terminates in a forward wall  2506 . Rear portion  2504  comprises a forward base section  2508 , preferably having four transversely extending outwardly facing protrusions  2509  extend therefrom, each protrusion being arranged at generally right angles with respect to its neighboring protrusions. 
         [0411]    Rearward of base section  2508  there are formed a plurality of tabs  2510  each having a rectangular window  2512 . Rearward of rectangular windows  2512  and on an inner surface  2514  of each of tabs  2510  there are preferably formed two radially extending inwardly facing protrusions  2516  each having an inclined surface. Protrusions  2516  preferably terminate at a forward end thereof in an inwardly facing transversely extending protrusion  2518 . Rearward of protrusions  2516 , each of tabs  2510  preferably includes an outwardly tapered portion  2520 . 
         [0412]    A hollow vial puncturing spike  2522  extends rearwardly from a rearward surface  2524  of forward wall  2506 , and is surrounded by base section  2508  and by tabs  2510 . Rearward surface  2524  additionally includes a circular cylindrical protrusion  2525 , surrounding puncturing spike  2522 . Two axially extending bores  2526  and  2527  extend through vial puncturing spike  2522 . 
         [0413]    Forward of forward wall  2506  of rear portion  2504  there is formed an intermediate portion which formed of two generally rectangular surfaces  2528 , and includes an axial tubular portion  2530  having a bore  2531  extend therethrough, bore  2531  being in fluid flow engagement with bore  2526  of hollow vial puncturing spike  2522 . 
         [0414]    On the top rectangular surface  2528  and slightly recessed with respect thereto there is formed a plastic membrane support surface  2532 , having formed thereon a plurality of generally evenly distributed spherical protrusions  2534 , which are adapted to support hydrophobic membrane  2402  and prevent it from excessive inflation and from cracking. Membrane  2402  is adapted to allow free passage of air to and from main body element  2502 , but to prevent passage of liquid and air borne particles, microorganisms and aerosol. A preferred membrane  2402  is Model Versapor R 0.2 Micron which is commercially available from Pall Corporation of New York, U.S.A. 
         [0415]    A narrow bore  2537  connects membrane  2402  to bore  2531 , thus allowing pressure equalization in an evacuated drug vial  2020  upon connection of vial  2020  to the vial adaptor subassembly  2044 . When fluid first passes through the system during drug dilution, bore  2537  irreversibly fills with liquid, thus preventing air from escaping the system. 
         [0416]    Prevention of the escape of air from the system is necessary for the reversible transfer of liquid from the receptacle  2012  to the vial  2020  and vice versa. Air movement between vial  2020  and receptacle  2012  causes changes in pressure in the vial, thereby pushing liquid from the vial into the receptacle. 
         [0417]    A rim  2538  surrounding support surface  2532  is adapted to support an optional carbon cloth filter  2404  and maintain it in a raised position above and spaced from membrane  2402 . Carbon filter  2404  is adapted to prevent toxic vapors from escaping from main body element  2502 , thus protecting users. A preferred carbon cloth filter  2404  is Model No. Zorflex EMI which is commercially available from Charcoal Cloth International Ltd. of Houghton-le-Spring, England. 
         [0418]    Rectangular surfaces  2528  of the intermediate portion terminate at a forward end thereof in a forward facing cylindrical portion  2548 , having a bore  2550  extend therethrough. Preferably, bore  2550  is a continuation of tubular portion  2530  of the intermediate portion. 
         [0419]    It is appreciated that the functionalities of membrane  2402  and carbon cloth filter  2404 , to allow free passage of air into the drug mixing system while preventing passage thereinto of liquid and air-borne particles, microorganisms and aerosol and preventing toxic vapors from escaping from the drug mixing system, may be incorporated, using similar elements, into any receptacle adaptor subassembly  2046 . 
         [0420]    Reference is now made to  FIG. 62 , which is a simplified pictorial illustration of receptacle adaptor subassembly  2046  which forms part of the adaptor assembly  2040  of  FIG. 59  and to  FIGS. 63A and 63B , which are sectional illustrations taken along respective section lines LXIIIA-LXIIIA and LXIIIB-LXIIIB in  FIG. 62 . 
         [0421]    As seen in  FIGS. 62-63B , receptacle adaptor subassembly  2046  includes a main body element  2600  which is arranged generally about an axis  2601 . Main body element  2600  is preferably integrally formed of plastic, and is preferably side-to-side symmetric about axis  2601 . Main body element  2600  preferably includes a generally cylindrical base portion  2602  terminating in a rear portion  2604 . 
         [0422]    Top and bottom generally concave wall portions  2606  are formed at a forward end of base portion  2602 , each wall portion  2606  defining on an outer surface thereof an outwardly facing axially extending rib  2608 , which extends from a forwardmost end of each of wall portions  2606  and along base portion  2602 . 
         [0423]    A connection surface  2610  extending transversely from side surfaces  2612  of base portion  2602  connects an outwardly extending arm  2614  to each side surface  2612 . Each arm  2614  preferably has a generally square rear portion  2616 , formed rearwardly of connection surface  2610 , and has a radially extending outwardly facing protrusion  2618  formed thereon. Protrusion  2618  preferably extends onto an outer surface of a generally rectangular forward portion  2620  of each of arms  2614 , which extends forwardly of connection surface  2610 . 
         [0424]    An inwardly facing generally triangular tooth  2622  is formed adjacent a top end of each of forward portions  2620 . Each tooth  2622  preferably includes a forwardly facing inclined surface  2624  and a rearwardly facing engagement surface  2626 . 
         [0425]    Rear portion  2604  preferably includes a transversely extending generally circular portion  2630  which forms a base for ribs  2608  and which terminates at a rear end thereof in an axially extending generally cylindrical wall portion  2632 . 
         [0426]    Wall portion  2632  preferably defines on a top and bottom surface thereof a small generally rectangular window  2634 , and two forwardly facing slots  2636  which are formed on either side of window  2634 . Two generally symmetric side-facing tabs  2638  are formed on side surfaces  2640  of wall portion  2632 , each tab  2638  being formed forwardly of a generally rectangular forwardly facing slot  2642 . 
         [0427]    Rear connection element  2406  preferably includes a forward disk  2652  defining a central bore  2654 . Disk  2652  preferably functions as a terminating wall for a forward facing cylindrical portion  2656 . Rearward of disk  2652  there is preferably formed a rear portion  2658 , having a narrow bore  2660  extend therethrough. Bore  2660  preferably widens toward the rear end of rear portion  2658 , thus enabling rear portion  2658  to connect to an appropriate port. Preferably, two generally symmetric tabs  2662  are formed on top and bottom surfaces of rear portion  2658 . Cylindrical portion  2656  preferably has an outer circumference that is slightly smaller than that of wall portion  2632 , and is located therein. 
         [0428]    Needle holding element  2408  preferably supports needle  2410  on a generally circular disk portion  2672 . Needle  2410  extends axially through base portion  2602  of main body element  2600  and through bore  2660  of rear connection element  2650 . Disk portion  2672  is preferably seated in cylindrical portion  2656 , and is locked into cylindrical portion  2656  by portion  2630 . 
         [0429]    Reference is now made to  FIGS. 64A and 64B , which are simplified pictorial illustrations of the housing element  2050  which forms part of the adaptor assembly  2040  of  FIG. 59  in closed and open orientations, respectively. 
         [0430]    As seen in  FIGS. 64A and 64B , housing element  2050  is preferably integrally formed about an axis  2700  and includes a top housing portion  2701  and a bottom housing portion  2702 . Preferably, housing portions  2701  and  2702  are side-to-side symmetric about axis  2700 . Preferably, each of housing portions  2701  and  2702  includes a semi-cylindrical forward portion  2704  and a semi-cylindrical rearward portion  2706 . 
         [0431]    Top and bottom housing portions  2701  and  2702  each include an inwardly recessed portion  2708  including a generally central elongate protrusion  2710 . 
         [0432]    Top housing portion  2701  includes at forward and rearward ends thereof outwardly extending fingers  2722  terminating in a generally triangular teeth  2724  which include inclined outwardly facing surfaces  2726  and engagement surfaces  2728 . Bottom housing portion  2702  preferably includes at forward and rearward ends thereof two generally rectangular windows  2730  which are placed generally below fingers  2722  and are adapted to engage engagement surfaces  2728  of fingers  2722  when housing element  2050  is assembled. 
         [0433]    An inner surface  2734  of housing element  2050  preferably includes at a rearward end thereof a circumferential recess  2736  which is adapted to engage protrusions  2509  of rear portion  2504  of vial adaptor subassembly  2044 . An outer surface of housing element  2050  which lies above recess  2736  preferably includes an outwardly facing protrusion  2740  which protrudes out of cylindrical rearward portion  2706 . 
         [0434]    Reference is now made to  FIG. 65 , which is a simplified assembled pictorial illustration of the adaptor assembly  2040  of  FIG. 59  and to  FIGS. 66A and 66B , which are sectional illustrations taken along respective section lines LXVIA-LXVIA and LXVIB-LXVIB in  FIG. 65 . 
         [0435]    As seen in  FIGS. 65-66B , rear portion  2504  of vial adaptor subassembly  2044  extends from a rear portion of housing element  2050 . Vial puncturing spike  2522  preferably extends out of housing element  2050 , and is accessible for connection of vial  2020  or of vial  2026  ( FIG. 54B ) thereto. 
         [0436]    Preferably, circumferential recess  2736  of inner surface  2734  of housing element  2050  engages protrusions  2509  of rear portion  2504  of vial adaptor subassembly  2044 . Preferably, forward facing cylindrical portion  2548  engages rear portion  2658  of rear connection element  2406 . A rear end of needle  2410  at least partially extends through bore  2660  and through bore  2550  such that bore  2550  is in fluid flow communication with needle  2410  of receptacle adaptor subassembly  2046 . 
         [0437]    A forward portion of main body element  2600  of receptacle adaptor subassembly  2046  preferably extends from a forward portion of housing element  2050  of adaptor assembly  2040 , and surrounds needle  2410  enclosed in needle protection element  2412 . Main body element  2600  including needle  2410  and needle protection cover  2412  is preferably accessible for connection of spike port adaptor element  2010  ( FIGS. 57-58 ) thereto. 
         [0438]    Housing element  2050  is preferably assembled, such that top housing portion  2701  and bottom housing portion  2702  are connected by engagement of engagement surfaces  2728  of teeth  2724  of top housing portion  2701  and windows  2730  of bottom housing portion  2702 . 
         [0439]    Reference is now made to  FIGS. 67A and 67B , which are sectional illustrations of the drug mixing system of  FIG. 54B  during attachment of vial  2020  to the vial adaptor subassembly  2044  of adaptor assembly  2040  of  FIG. 65 . 
         [0440]    Vial  2026  and vial head adaptor element  2030  joined thereto ( FIG. 54C ) or vial  2020  is preferably pushed into engagement with vial puncturing spike  2522  of vial adaptor subassembly  2044 . 
         [0441]    Typically, vial puncturing spike  2522  of vial adaptor subassembly  2044  punctures septum  2024  located inside top portion  2022  of vial  2020 , thus enabling fluid flow between the main body of vial  2020  and bore  2550  of cylindrical portion  2548  of main body element  2502  of vial adaptor subassembly  2044 . Preferably, puncturing of septum  2024  releases any vacuum in vial  2020  by entrance of air into vial  2020  through optional carbon cloth filter  2404  ( FIG. 61A ) and membrane  2402  ( FIG. 61A ). 
         [0442]    Engagement between vial adaptor subassembly  2044  and vial  2010  is preferably maintained by snap engagement of protrusions  2516  and  2518  of rear portion  2504  of main body element  2600  with neck portion  2023  of vial  2020 . The engagement of protrusions  2516  and  2518  with neck portion  2023  ensures that vial adaptor subassembly  2044  is latched onto vial  2020  and cannot be removed therefrom. Tabs  2510  and outwardly tapered portions  2520  generally surround top portion  2022  and neck portion  2023  of vial  2020 . 
         [0443]    At this stage, the main body of vial  2020  is in fluid flow communication with needle  2410  via vial puncturing spike  2522 , bore  2550  of cylindrical portion  2548  and bore  2660  of cylindrical portion  2658 . 
         [0444]    Reference is now made to  FIG. 68 , which is a sectional illustration of the drug mixing system of  FIG. 54D-54G  during attachment of the receptacle port adaptor element  2010  and receptacle  2012  of  FIG. 54A  to the receptacle adaptor subassembly  2046  of adaptor assembly  2040  of  FIG. 67 , having vial  2020  attached thereto. 
         [0445]    As seen in  FIG. 68 , spike port adaptor element  2010 , having receptacle  2012  joined thereto, is connected to receptacle adaptor subassembly  2046  of adaptor assembly  2040 . 
         [0446]    Spike  2308  is preferably previously inserted into spike port  2011  of receptacle  2012 , such that bore  2310  of spike element  2306  engages fluid content of receptacle  2012 . Connection port  2318  of spike port adaptor element  2010  engages wall portions  2606  and base portion  2602  of main body element  2600  of receptacle adaptor subassembly  2046 . 
         [0447]    Connection port  2318  is preferably locked into connection with receptacle adaptor subassembly  2046  by engagement of engagement surfaces  2626  of forward portions  2620  of awls  2614  and a rearward facing wall portion of connection port  2318 . Preferably, needle  2410  punctures needle protection cover  2412  and septum  2320 , resulting in partial collapse of the needle protection cover. At this stage, receptacle  2012  is in fluid flow communication with the main body of vial  2020  via bore  2310  of spike  2308  of spike port adaptor element  2010 , needle  2410 , bore  2660 , bore  2550  of cylindrical portion  2548 , bore  2531  of tubular portion  2530  and vial puncturing spike  2522 . 
         [0448]    Reference is now made to  FIG. 69 , which is a sectional illustration of the drug mixing system of  FIGS. 54H and 68  during disconnection of the spike port adaptor element  2010  and receptacle  2012  from the receptacle adaptor subassembly  2046  of adaptor assembly  2040  of  FIG. 67 . 
         [0449]    As shown in  FIG. 69 , spike port adaptor element  2010  and receptacle  2012  joined thereto are disconnected from receptacle adaptor subassembly  2046  of adaptor assembly  2040 . Typically, spike port adaptor element  2010  is disconnected from receptacle adaptor subassembly  2046  by slightly pushing arms  2614  extending from side surfaces  2612  of base portion  2602 , causing teeth  2620  to move outward and release the rearward facing wall portion of connection port  2318 , thus disconnecting the connection port. Typically, needle  2410  is released from connection port  2318 , and needle protection cover  2412  is deployed and once again fully encloses needle  2410 , thus sealing it to prevent leakage. 
         [0450]    Reference is now made to  FIG. 70  which is a simplified exploded view illustration of a drug mixing system constructed and operative in accordance with a further preferred embodiment of the present invention. The embodiment of  FIG. 70  is a modification of the embodiments of  FIGS. 31A-53  and  54 A- 69 . Accordingly, for the sake of conciseness, it is described hereinbelow in somewhat abbreviated faun with reference to  FIGS. 71-78 . 
         [0451]    In this embodiment the drug vial is enclosed in a protective housing used during storage and dilution, thereby preventing spills in case of breakage. 
         [0452]    As seen with particular clarity in  FIG. 70 , the drug mixing system comprises a vial adaptor subassembly  3000 , which preferably comprises an externally threaded vial support element  3010 , into which is placed a vial  3020 . 
         [0453]    A vial puncturing cover assembly  3030  comprises an internally threaded covering element  3032 , which connects at a forward end thereof to the externally threaded portion of vial support element  3010 . At a top end thereof, covering element  3032  engages a vial puncturing spike element  3034 , which supports a hydrophobic membrane  3036 . 
         [0454]    Vial puncturing cover assembly  3030  connects at a forward end thereof to a connection port of a receptacle adaptor subassembly  3040 , which is adapted to engage a spike port receptacle adaptor element  3050 . Spike port receptacle adaptor element  3050  is preferably inserted into a receptacle port  3051  of a receptacle  3052 . 
         [0455]    Alternatively, vial puncturing cover assembly  3030  may connect at a forward end thereof to a vial port  3080  of a stopcock  3082 , and the connection port of receptacle port adaptor assembly  3040  connects to a receptacle port  3084  of stopcock  3082 . When this option is used, a syringe port  3086  of stopcock  3082  preferably engages a luer fitted syringe. 
         [0456]    It is appreciated that vial  3020  may be identical to either of vials  2020  and  2026 , and that receptacle  3052  may be identical to receptacle  2012 , described hereinabove with reference to  FIGS. 54A-54C . 
         [0457]    Receptacle adaptor subassembly  3040  may be identical to receptacle adaptor subassembly  2046 , described hereinabove with reference to  FIGS. 62-63B . 
         [0458]    Spike port adaptor element  3050  may be identical to spike port adaptor element  2010 , described hereinabove with reference to  FIGS. 57-58 . 
         [0459]    Reference is now made to  FIG. 71  which is a simplified pictorial illustration of a vial support element  3010  which forms part of vial adaptor subassembly  3000  of the drug mixing system of  FIG. 70  and to  FIGS. 72A and 72B  which are, respectively, a sectional illustration and a pictorial sectional illustration taken along section lines LXXII-LXXII in  FIG. 71 . 
         [0460]    Vial support element  3010  comprises a generally cylindrical body element  3100  arranged generally about an axis  3101 . Body element  3100  is preferably integrally formed and preferably is generally side-to-side symmetric about axis  3101 . 
         [0461]    Body element  3100  preferably includes a top portion  3102 , which is externally threaded and which is separated from a bottom portion  3104  by an outwardly facing circumferential protrusion  3106 . Four axially extending outwardly facing protrusions  3108  are preferably formed on bottom portion  3104 , each protrusion  3108  being arranged at generally right angles with respect to its neighboring protrusions. 
         [0462]    Body element  3100  preferably terminates in a transversely extending base wall portion  3110 , which includes a central spherical protrusion  3112  which is adapted to center vial  3020  in vial support element  3010 . 
         [0463]    As seen with particular clarity in  FIG. 72B , an inner surface  3114  of body element  3100  may optionally include a plurality of axially extending inwardly facing generally rectangular protrusions  3116 , which are operative to adapt vial support element  3010  to support a smaller vial. Different body elements  3100 , molded with protrusions  3116  of different sizes, may be used for different vial sizes. Similarly, base wall portion  3110  may optionally be molded at various heights with respect to bottom portion  3104 , thus enabling different vial support elements  3010  to support vials of different heights. 
         [0464]    Reference is now made to  FIG. 73 , which is a simplified pictorial illustration of vial support element  3010  of  FIGS. 71-72B  containing a vial  3020  and to  FIG. 74 , which is a sectional illustration taken along section lines LXXIV-LXXIV in  FIG. 73 . 
         [0465]    As seen in  FIGS. 73 and 74 , vial  3020  is placed within vial support element  3010 , such that top portion  3022 , septum  3024  and at least part of neck portion  3023  extend above the vial support element and are accessible to a user. 
         [0466]    A base of vial  3020  is preferably seated on base wall portion  3110  and engages spherical protrusion  3112 . 
         [0467]    Reference is now made to  FIGS. 75A and 75B , which are simplified pictorial illustrations of vial puncturing cover assembly  3030  which forms part of the vial adaptor subassembly  3000  of  FIG. 70  and to  FIG. 76  which is a sectional illustration taken along section lines LXXVI-LXXVI in  FIG. 75A . 
         [0468]    Vial puncturing cover assembly  3030  includes covering element  3032 , which comprises a generally cylindrical main body portion  3202  arranged generally about an axis  3203 . 
         [0469]    Main body portion  3202  is preferably internally threaded and is adapted to engage the externally threaded top portion  3102  of vial support element  3010 . Four axially extending outwardly facing protrusions  3204  are preferably formed on an outer surface  3205  of main body portion  3202 , each protrusion  3204  being arranged at generally right angles with respect to its neighboring protrusions. An outwardly facing radially extending wall portion  3206  extends from a bottom end of main body portion  3202 . 
         [0470]    Main body portion  3202  terminates in a wall portion  3208 , which preferably extends transversely with respect to axis  3203  and includes a generally round aperture  3210 . An inner surface  3212  of wall portion  3208  preferably includes two semi-circular tracks  3214 . 
         [0471]    Vial puncturing spike element  3034  preferably includes a vial puncturing spike  3220  extending through aperture  3210  of wall portion  3208 . Vial puncturing spike  3220  preferably has two axial bores  3222  and  3224  extending therethrough. 
         [0472]    Preferably membrane  3036  is in fluid flow engagement with cover element  3032  via bore  3224  of vial puncturing spike  3220 . 
         [0473]    Spike  3220  preferably extends forwardly from a generally circular wall portion  3226 , which engages a top surface of wall portion  3208 . Four generally rectangular wall portions  3228  extend radially from spike  3220 , each wall portion  3228  being arranged at generally right angles with respect to its neighboring wall portions. 
         [0474]    Wall portions  3228  preferably define at top surfaces thereof four spherical protrusions  3230 , which engage tracks  3214  and are adapted to lock vial puncturing spike element  3034  with respect to covering element  3032 . 
         [0475]    A generally cylindrical portion  3232 , including an axial bore  3234 , preferably extends rearwardly from wall portion  3226 . Cylindrical portion  3232  is preferably adapted to engage rear portion  3658  of receptacle adaptor subassembly  3040 . 
         [0476]    A second generally cylindrical portion  3236  preferably extends rearwardly of wall portion  3226  and adjacent cylindrical portion  3232 . Portion  3236  preferably defines a seat  3238  which is adapted to support unidirectional breathing membrane  3036  and prevent it from excessive inflation and from cracking. Membrane  3036  is adapted to allow free passage of air into the main body element  3032 , but prevent passage therethrough of liquid and air-borne particles, microorganisms and aerosol. A preferred membrane  3036  is Model Versapor R 0.2 Micron which is commercially available from Pall Corporation of New York, U.S.A. 
         [0477]    Reference is now made to  FIG. 77 , which is a simplified assembled pictorial illustration of the vial adaptor subassembly  3000  of  FIG. 70  and to  FIG. 78 , which is a sectional illustration taken along section lines LXXVIII-LXXVIII in  FIG. 77 . 
         [0478]    As seen in  FIGS. 77 and 78 , vial puncturing cover assembly  3030  threadably engages vial support element  3010 , thus enclosing therein vial  3020 . 
         [0479]    The threaded engagement between vial support element  3010  and vial puncturing cover element  3032  causes puncturing spike  3220  to be pushed into engagement with vial  3020 . 
         [0480]    Typically, vial puncturing spike  3220  of vial puncturing cover element  3030  punctures septum  3024  located inside top portion  3022  of vial  3020 , thus enabling fluid flow between the main body of vial  3020  and bore  3234  of cylindrical portion  3232  via bore  3222  of puncturing spike  3220 . Preferably, puncturing of septum  3024  releases any vacuum in vial  3020 . 
         [0481]    Reference is now made to  FIG. 79 , which is a pictorial illustration of the vial adaptor subassembly  3000  of  FIG. 77  when assembled to receptacle adaptor subassembly  3040  thus forming an adaptor assembly in accordance with a preferred embodiment of the present invention, and to  FIG. 80 , which is a sectional illustration taken along section lines LXXX-LXXX in  FIG. 79 . 
         [0482]    As seen in  FIGS. 79 and 80 , cylindrical portion  3232  of vial cover element  3030  engages rear portion  3658  of receptacle adaptor subassembly  3040 . A rear end of needle  3410  at least partially extends through bore  3660  and through bore  3234  such that bore  3234  is in fluid flow communication with needle  3410  of receptacle adaptor subassembly  3040 . Due to fluid flow communication between bore  3234  and the main body of vial  3020 , needle  3410  is in fluid flow communication with vial  3020 . 
         [0483]    A forward portion of main body element  3414  of receptacle adaptor subassembly  3040  preferably surrounds needle  3410  enclosed in needle protection element  3412 . Main body element  3600  including needle  3410  and needle protection cover  3412  is preferably accessible for connection of spike port adaptor element  3050  thereto. 
         [0484]    It is appreciated that cylindrical portion  3232  of vial cover element  3030  may alternatively engage a stopcock  3052 , which additionally engages receptacle adaptor subassembly  3040  and a syringe as described hereinabove with reference to  FIGS. 31A-53 . In such a case, the method of use of the system would be similar to that described in  FIGS. 31A-31L . 
         [0485]    Reference is now made to  FIG. 81 , which is a pictorial illustration of vial adaptor subassembly  3000  connected to receptacle adaptor subassembly  3040  of  FIG. 79  when connected to a spike port adaptor element  3050  and receptacle  3052  and to FIG.  82 , which is a sectional illustration taken along section lines LXXXII-LXXXII in  FIG. 81 . 
         [0486]    As seen in  FIGS. 81 and 82 , spike port adaptor element  3050 , having receptacle  3052  joined thereto, is connected to receptacle adaptor subassembly  3040 . 
         [0487]    A spike  3308  is preferably previously inserted into spike port  3051  of receptacle  3052 , such that a bore  3310  of a spike element  3306  engages fluid content of receptacle  3052 . A connection port  3318  of spike port adaptor element  3050  engages wall portions  3606  and base portion  3602  of main body element  3414  of receptacle adaptor subassembly  3040 . 
         [0488]    Connection port  3318  is preferably locked into connection with receptacle adaptor subassembly  3040  by engagement of engagement surfaces  3626  of forward portions  3620  of arms  3614  and a rearward facing wall portion of connection port  3318 . 
         [0489]    Preferably, needle  3410  punctures needle protection cover  3412  and septum  3320 , resulting in partial collapse of the needle protection cover. At this stage, receptacle  3052  is in fluid flow communication with the main body of vial  3020  via bore  3310  of spike  3308  of spike port adaptor element  3050 , needle  3410 , bore  3660 , bore  3234  of cylindrical portion  3232  and vial puncturing spike  3220 . 
         [0490]    Reference is now made to  FIG. 83 , which is a simplified exploded view illustration of a drug mixing system constructed and operative in accordance with a still further preferred embodiment of the present invention. The embodiment of  FIG. 83  is a modification of the embodiment of  FIGS. 54A-69 . Accordingly, for the sake of conciseness, it is described hereinbelow in somewhat abbreviated form with reference to  FIGS. 84-92 . 
         [0491]    As seen with particular clarity in  FIG. 83 , the drug mixing system comprises a receptacle adaptor subassembly  4000  which preferably comprises a receptacle adaptor housing element  4010 . Receptacle adaptor housing element  4010  preferably engages a receptacle adaptor needle assembly  4020 . Receptacle adaptor subassembly  4000  preferably engages a port such as a receptacle port  4031  of a receptacle  4032 . 
         [0492]    Receptacle adaptor needle assembly  4020  connects at a rearward end thereof to a connection port of a vial adaptor subassembly  4040 , which is adapted to engage a vial  4050 . 
         [0493]    It is appreciated that vial  4050  may be identical to either of vials  2020  and  2026 , and receptacle  4032  may be identical to receptacle  2032 , described hereinabove with reference to  FIGS. 54A-54C . 
         [0494]    Vial adaptor subassembly  4040  may be identical to vial adaptor subassembly  2046 , described hereinabove with reference to  FIGS. 60-61B . 
         [0495]    Receptacle port  4031  may be identical receptacle port  2031 , described hereinabove. It is appreciated that receptacle adaptor subassembly  4000  may engage a spike port adaptor element such as spike port adaptor element  2030  described hereinabove with reference to  FIGS. 57-58 . 
         [0496]    Reference is now made to  FIG. 84 , which is a simplified pictorial illustration of receptacle adaptor housing element  4010  which fauns part of the drug mixing system of  FIG. 83  and to  FIGS. 85A and 85B , which are sectional illustrations taken along section lines LXXXVA-LXXXVA and LXXXVB-LXXXVB in  FIG. 84 . 
         [0497]    Receptacle adaptor housing element  4010  comprises a body element  4100 , arranged generally about an axis  4101 . Body element  4100  comprises a tube of generally rectangular cross-section, is preferably integrally formed and preferably is generally side-to-side symmetric about axis  4101 . 
         [0498]    Body element  4100  preferably includes a rear portion  4102  which is formed with ribbed grip regions  4104  on an outer surface  4106 . Two elongate windows  4108  are preferably formed on top and bottom surfaces of rear portion  4102 . 
         [0499]    A forward portion  4110  of body element  4100  has a slightly smaller outer circumference than that of rear portion  4102 , and includes a generally rectangular window  4112  on each of the surfaces thereof. Forward portion  4110  preferably sealingly accommodates a septum  4114  in a seat  4116 . 
         [0500]    Four axially extending tabs  4118  extend forwardly of forward portion  4110 , each tab  4118  being arranged at generally right angles with respect to its neighboring tabs. Each tab  4118  preferably includes and an inwardly facing tooth  4120  and preferably terminates in an outwardly tapered portion  4122 . 
         [0501]    Reference is now made to  FIG. 86 , which is a simplified pictorial illustration of receptacle adaptor needle assembly  4020  which forms part of the drug mixing system of  FIG. 83  and to  FIGS. 87A and 87B , which are sectional illustrations taken along section lines LXXXVIIA-LXXXVIIA and LXXXVIIB-LXXXVIIB in  FIG. 86 . 
         [0502]    Receptacle adaptor needle assembly  4020  comprises a generally cylindrical body element  4200 , arranged generally about an axis  4201 . Body element  4200  is preferably integrally formed and preferably is generally side-to-side symmetric about axis  4201 . 
         [0503]    Body element  4200  preferably includes a rear connection port  4202  which is separated from a forward portion  4204  by a circumferential outwardly extending protrusion  4206 . Protrusion  4206  is adapted to limit the extent to which receptacle adaptor needle assembly  4020  is inserted into receptacle adaptor housing element  4010 . 
         [0504]    Forward portion  4204  preferably terminates in a forward wall portion  4205  from which extends a cylindrical portion  4210  having an outer circumference which is slightly larger than that of forward portion  4204 . Cylindrical portion  4210  preferably has formed thereon four axially extending protrusions  4212 , each protrusion  4212  being arranged at generally right angles with respect to its neighboring protrusions. 
         [0505]    Two outwardly extending arms  4214  are formed at a forward end of cylindrical portion  4210 , each aim  4214  being generally across from the other arm. Protrusions  4212  and arms  4214  are preferably rotationally offset from one another about axis  4201 . Each arm  4214  preferably defines at a forward most end thereof a generally triangular tooth  4216  including an engagement surface  4218 . 
         [0506]    A hollow needle  4220  is preferably sealingly mounted in a cylindrical portion  4222  which is formed within cylindrical portion  4210  of receptacle adaptor needle assembly  4020 . 
         [0507]    Reference is now made to  FIG. 88 , which is a simplified assembled pictorial illustration of the receptacle adaptor subassembly  4000  of  FIG. 83  and to  FIGS. 89A and 89B , which are sectional illustrations taken along section lines LXXXIXA-LXXXIXA and LXXXIXB-LXXXIXB in  FIG. 88 . 
         [0508]    As seen in  FIG. 88-89B , cylindrical portion  4210  of receptacle adaptor needle assembly  4020  preferably engages a rearwardmost portion of rear portion  4102  of receptacle adaptor housing element  4010 . Teeth  4216  of arms  4214  of cylindrical portion  4210  preferably extend through windows  4108  and maintain receptacle adaptor needle assembly  4020  locked in receptacle adaptor housing element  4010 . 
         [0509]    It is appreciated that a user may push receptacle adaptor needle assembly  4020  inward with respect to receptacle adaptor housing element  4010 . Such inward motion of receptacle adaptor needle assembly  4020  is limited by protrusion  4206 . 
         [0510]    Reference is now made to  FIG. 90 , which is a pictorial illustration of the receptacle adaptor subassembly  4000  of  FIG. 88  when assembled to a vial adaptor subassembly  4040  and to port  4031  of receptacle  4032 , prior to insertion of needle  4220  into the receptacle port  4031  and to  FIG. 91 , which is a sectional illustration taken along section lines XCI-XCI in  FIG. 90 . 
         [0511]    Vial  4050  is preferably pushed into engagement with a vial puncturing spike  4522  of vial adaptor subassembly  4040 . 
         [0512]    Typically, vial puncturing spike  4522  of vial adaptor subassembly  4050  punctures a septum  4014  located inside a top portion  4012  of vial  4050 , thus enabling fluid flow between the main body of vial  4050  and a bore  4550  of a cylindrical portion  4548  of main body element  4502  of vial adaptor subassembly  4050 . Preferably, puncturing of septum  4014  releases any vacuum in vial  4050  by entrance of air into vial  4050  through a carbon filter  4404  and a membrane  4402 . 
         [0513]    Engagement between vial adaptor subassembly  4040  and vial  4050  is preferably maintained by snap engagement of protrusions  4516  and  4518  of rear portion  4504  of main body element  4502  with neck portion  4013  of vial  4050 . The engagement of protrusions  4516  and  4518  with neck portion  4013  ensures that vial adaptor subassembly  4040  is latched onto vial  4050  and cannot be removed therefrom. Tabs  4510  and outwardly tapered portions  4520  generally surround top portion  4012  and neck portion  4013  of vial  4050 . 
         [0514]    Cylindrical portion  4548  preferably engages connection port  4202  of receptacle adaptor needle assembly  4020 , such that needle  4220  is in fluid flow communication with vial  4050  via forward portion  4204 , bore  4550  of cylindrical portion  4548  and vial puncturing spike  4522 . The sharpened tip of needle  4220  preferably partially extends through septum  4114 . 
         [0515]    Teeth  4120  of arms  4118  preferably engage receptacle port  4031  of receptacle  4032 , or may alternatively engage any other suitable port such as a spike port adaptor element  4030  as described hereinabove. 
         [0516]    Reference is now made to  FIG. 92 , which is a pictorial illustration of the receptacle adaptor subassembly  4000  of  FIG. 88  when assembled to a vial adaptor subassembly  4040  and to port  4031  of receptacle  4032 , following insertion of needle  4220  into receptacle port  4031  and to  FIG. 93 , which is a sectional illustration taken along section lines XCIII-XCIII in  FIG. 92 . 
         [0517]    As seen in  FIGS. 92 and 93 , a user preferably pushes receptacle adaptor needle assembly  4020  inward, such that needle  4220  pierces septum  4114 , resulting in fluid flow communication between receptacle  4032  and vial  4050 . 
         [0518]    It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of various features described hereinabove as well as modifications thereof which would occur to persons skilled in the art upon reading the foregoing specification and which are not in the prior art.
A drug mixing system including at least one receptacle port adaptor adapted to be inserted into a port of a fluid receptacle, at least one syringe adaptor adapted to be attached to a syringe and to the at least one receptacle port adaptor and at least one vial adaptor adapted for connection to a vial containing a drug and adapted for connection to the at least one syringe adaptor, the system being characterized in that at least one of the receptacle port adaptor, the at least one syringe adaptor and the at least one vial adaptor being vented to the atmosphere in a manner which prevents release to the atmosphere of possibly harmful contents of the vial in a liquid, solid or gaseous form.