Abstract
Eye-drops are the conventional dosage forms that account for 90% of currently accessible ophthalmic formulations. Despite the excellent acceptance by patients, one of the major problems encountered is rapid pre-corneal elimination of drug resulting in poor bioavailability and therapeutic response. This problem can be tackled by using in situ gelling system which are prepared from polymer which exhibit sol-to-gel phase transition due to change in a specific physiochemical parameter such as pH, temperature, and ion-sensitive. The sol-gel transition occurs as a result of a chemical/ physical change induced by physiological environment. In situ gelling systems are preferred as they can be delivered in drop form with sustained release properties. This type of gel combines the advantage of solution (accurate and reproductive administration of drug) and gels ( prolong residence time) for improving ocular bioavailability. Current review intends to summarize the existing conventional formulations for ocular delivery and their advancements followed by current nanotechnology based formulation developments. Also, recent developments with other ocular drug delivery strategies employing in situ gels, implants, contact lens, erodible inserts have been discussed.
