ABSTRACT:
Recently, controlled and sustained drug delivery has become the standard in modern Pharmaceutical design. This interest has been sparked by the advantages shown by in situ forming gelling systems such as ease of administration and reduced frequency of administration, improved patient compliance and comfort. This review article explores the functional activity and development aspects of in situ gel for the visual system. Approximately 314 million people worldwide live with serious vision impairment. Without effective, major intervention, the number of blind people worldwide has been projected to increase to 76 million by 2020. The anatomical structure and the protective physiological process of the eye exert a formidable defense against ophthalmic drug delivery. The primitive ophthalmic solution, suspension, and ointment dosage forms are clearly no longer sufficient to combat eye diseases. The major problem encountered is rapid precornel drug loss and poor ocular bioavailability. The poor bioavailability and therapeutic response exhibited by the conventional ophthalmic solutions due to pre-corneal elimination of the drug may be overcome by the use of in situ gel forming systems, which upon instillation as drops into the eye undergo a solgel transition in the cul-de-sac.