AN INSIGHT TO OPHTHALMIC IN-SITU GEL: AN OVERVIEW

Abstract

Ocular drug delivery has been a major challenging and interesting field for the pharmaceutical scientists due to unique anatomy and physiology of the eye. The major problem encountered in ocular drug delivery is the rapid loss of the drug through lachrymal drainage which results in poor bioavailability and therapeutic response of the drug. There are some static (different layers of the eye i.e. cornea, sclera, retina) and dynamic (blood aqueous and blood retinal barrier) barriers which also affect the bioavailability of the drug. In-situ gels are the liquid preparations which upon instillation undergoes the phase transition in cul-de sac in the eyes to form a viscous gel and this occurs due to environmental changes in the eye ( due to change in pH, change in temperature and ion- induced). This review is to specify the different phase transition process and polymers used in forming in-situ gelling system.