Current research and development strategy focus on development of drug delivery system that makes clinically established drugs to their therapeutic best rather than search for new drug in the traditional hit or miss way. Ophthalmic products, like most other product in the medical armamentarium are currently undergoing a process termed optimization. New modes of delivering a drug to the eye are being activity explored, ranging from a solid hydrophobic device that is inserted into the ophthalmic cul-de-sac, to conventionally applied dosage from which due to their formulation characteristic markedly increases the drug residence time in the orbit of eye, thus providing drug for absorption for prolonged periods are for absorption for prolonged periods are reducing the frequency of drug administration. [1] Poor bioavailability of many drugs from topical ophthalmic preparation limits therapeutic drug delivery. Furthermore treatment of several posterior segment disorders requiring therapeutic intravitreal drug level necessitate repeated injections off drugs due to the short residence time of drug in the vitreous cavity. Substantial effort has been directed towards the development of ocular and intraocular drug delivery of ocular and intraocular drug delivery system that would prolong the drug retention allowing the drug to remain in the contact with ocular milieu for longer duration and thus maximize bioavailability. Beyond the issue of bioavailability, patient compliance and dexterity issue for drug installation are other important consideration that may impact therapeutic drug delivery
