FORMULATION, DEVELOPMENT AND EVALUATION OF OCULAR IN SITU GEL OF NSAIDS DRUG NEPAFENAC

In situ gels are systems which are applied as solutions or suspensions and are capable of undergoing rapid sol-to-gel transformation triggered by external stimulus such as temperature, pH etc. on instillation. The aim of the present study was to formulate and evaluate pH responsive in-situ gel for ophthalmic delivery. Ophthalmic nepafenac is used to treat eye pain, redness, and swelling in patients who are recovering from cataract surgery (procedure to treat clouding of the lens in the eye). Nepafenac is in a class of medications called nonsteroidal anti-inflammatory drugs (NSAIDs). It works by stopping the production of certain natural substances that cause pain and swelling. Ophthalmic in situ gelling system of Nepafenac was successfully formulated using polymeric combination of gelling agents Pluronic F127, Carbopol 934 as, temperature sensitive and pH-sensitive respectively along with HPMC 15cps as viscosity enhancing agent.  All the formulations except F7, F8 and F9 showed instantaneous gelation when contacted with simulated tear fluid (STF), formulation F6 showed best gelation property amongst all other. Formulation F6 showed sustained drug release for a period of 6 hour.  The In vitro drug release data of the optimized formulation was subjected to goodness of fit test by linear regression analysis according to zero order, first order Higuchi and Korsmeyerpeppas release kinetic equation in order to determine the mechanism of drug release.

Key words:Nepafenac, nonsteroidal anti-inflammatory drugs, Ophthalmic, In situ gel