FORMULATION DEVELOPMENT AND EVALUATION OF ION SENSITIVE IN SITU OPHTHALMIC GEL OF OLOPATADINE HYDROCHLORIDE

The poor bioavailability of ophthalmic solutions caused by dilution and drainage from the eye can be overcome by using in situ forming ophthalmic drug delivery system prepared from polymer that exhibit reversible liquid–gel phase transition. The objective of the study was to develop optimized formulation of in situophthalmic gel of Olopatadine hydrochloride using ion activated polymer, Gelrite (gellan gum) as a gelling polymer, HPMC E-50LV (hydroxyl propyl methyl cellulose) as release retardant and benzalkonium chloride as a preservative. The 3 2 full factorial design was employed to optimize the formulation wherein HPMC E-50LV (X1) and Gelrite (X2) were taken as independent variables & the dependent variables were viscosity (Y1) and release of drug (Y2). The formulations were assessed for appearance, gelation ability, sterility, pH, drug content, viscosity, release through cellophane membrane & corneal membrane of goat, ocular irritation study & stability study. The developed formulations F4 and F5 werefound to be stable, non-irritant to rabbit eyes and in vitro drug release were found to be 94.88% and 95.02% over the period of 12 hr through cellophane membrane and 92.17% and 90.87% through corneal membrane of goat respectively. The stable in situ gelling system of Olopatadine hydrochloridewas successfully developed using Gelrite and HPMC E-50LV.