a free - flowing anti - coagulant powder composition , the anti - coagulant composition containing heparin and a bulking agent that is lyophilized or spray dried and ground into a powder . the powdered anti - coagulant composition can be dry filled into syringes and other blood collections systems for rapid dissolution and mixing with collected blood sample without agitation of the container . the formulation may also retain a portion of the initial moisture , which may improve the shelf life and stability of the composition .