the in - vivo study on ophthalmic products is done on experimental animals , usually on rabbit 's eye .
preparation volume 50 l is instilled topically in the center of the lower cul - de - sac .
eyes of the animal are observed for signs of irritation and injury . in vitro methods
diclofenac sodium solid lipid nanoparticles ( slns ) , prepared with goat fat and phospholipids evaluated using bio - engineered human cornea , produced from immortalized human corneal endothelial cells ( henc ) , stromal fibroblasts , and epithelial cells .
sustained release and high permeation of diclofenac sodium through the bio - engineered cornea were achieved .
the bovine corneal opacity and permeability ( bcop ) assay has been accepted as a valid in - vitro alternative method to the draize eye irritation test with the development of an improved laser light - based opacitometer ( llbo ) for the analysis of the complete corneal surface instead of dual beam op - kit opacitometer .
confocal laser scanning microscopy study on the transport mechanism through the corneal epithelium of nanostructured lipid carrier was carried out in rabbits in vivo .
the corneas were isolated and rinsed in physiological saline to remove the adhesive fluorescence fragment .
after 30 minute administration in to eyes , the interaction with corneal epithelia to be investigated by observing the corneal samples using confocal laser scanning microscopy ( clsm ) .
the epiocular tissue model is a new in - vitro test method for ocular irritation , produced by mattek corporation tissue production facilities .
the epiocular tissue model shows in - vivo like morphological and growth characteristics that are uniform and highly reproducible .
the tissue consists of highly organized basal cells , which progressively flatten out as the apical surface of the tissue similar to the normal in - vivo corneal epithelium .
this test could be applied as an alternate to rabbit eye test in the toxicological assessment of ophthalmic preparations .
the in - vivo study on ophthalmic products is done on experimental animals , usually on rabbit 's eye .
preparation volume 50 l is instilled topically in the center of the lower cul - de - sac .
eyes of the animal are observed for signs of irritation and injury . in vitro methods
diclofenac sodium solid lipid nanoparticles ( slns ) , prepared with goat fat and phospholipids evaluated using bio - engineered human cornea , produced from immortalized human corneal endothelial cells ( henc ) , stromal fibroblasts , and epithelial cells .
sustained release and high permeation of diclofenac sodium through the bio - engineered cornea were achieved .
the bovine corneal opacity and permeability ( bcop ) assay has been accepted as a valid in - vitro alternative method to the draize eye irritation test with the development of an improved laser light - based opacitometer ( llbo ) for the analysis of the complete corneal surface instead of dual beam op - kit opacitometer .
confocal laser scanning microscopy study on the transport mechanism through the corneal epithelium of nanostructured lipid carrier was carried out in rabbits in vivo .
the corneas were isolated and rinsed in physiological saline to remove the adhesive fluorescence fragment .
after 30 minute administration in to eyes , the interaction with corneal epithelia to be investigated by observing the corneal samples using confocal laser scanning microscopy ( clsm ) .
the epiocular tissue model is a new in - vitro test method for ocular irritation , produced by mattek corporation tissue production facilities .
the epiocular tissue model shows in - vivo like morphological and growth characteristics that are uniform and highly reproducible .
the tissue consists of highly organized basal cells , which progressively flatten out as the apical surface of the tissue similar to the normal in - vivo corneal epithelium .
this test could be applied as an alternate to rabbit eye test in the toxicological assessment of ophthalmic preparations .
most of the formulation efforts aim at maximizing ocular drug absorption through prolongation of the drug residence time in the eye as well as to slow drug release from the delivery system and minimize pre - corneal drug loss .
nanostructured platforms provide the effective ways for delivery of insoluble drugs to the target site .
as these platforms for ophthalmic delivery are very recent and the research continues , formulation factors such as loading of drug , release rate , stability , and therapeutic effectiveness for these needs to be optimized .
 the topically applied drugs as drops are washed off from the eye in very short period , resulting in low ocular bioavailability of drugs . 
 number of approaches have been attempted to increase the bioavailability and the duration of action of ocular drugs . 
 this review provides an insight into various novel approaches ; hydrophilic nanogels , solid lipid nanoparticles , and nanosponges applied very recently in the delivery of insoluble drugs , prolonging the ocular residence time , minimize pre - corneal drug loss and , therefore , bioavailability and therapeutic efficacy of the drugs . despite various scientific approaches , efficient ocular drug delivery remains a challenge for pharmaceutical scientists . 
None
Ophthalmic products toxicity evaluation
Conclusion