FORMULATION AND EVALUATION OF FLURBIPROFEN OCULAR IN-SITU GEL

Conventional ophthalmic preparations exhibit poor bioavailability due to the rapid precorneal elimination of the drug, and the physiological constraints imposed by the protective mechanisms of the eye lead to the low absorption of the drugs resulting in a short duration of the therapeutic effect. In order to increase the residence time of the drug in-situ gelling systems were prepared and instilled as drops into the eye which undergo a sol-gel transition in the cul-de-sac. The present work describes the formulation and evaluation of flurbiprofen ocular in-situ gel, based on the concept of pH – triggered in-situ gelation. Polyacrylic acid (carbopol) was used as the gelling agent in combination with hydroxy-propyl methyl cellulose (HPMC) which acted as a viscosity enhancing agent. The formulations were evaluated for clarity, pH measurement, gelling capacity, gelling temperature, drug content estimation, rheological study, in-vitro drug release study, sterility testing and stability studies. The physicochemical interactions between drug and polymers were investigated by fourier transform infrared (FTIR) spectroscopy. FTIR studies did not show any evidence of interaction between the drug and the polymers. The formulation F22 (containing 1% HPMC E15, 0.3% carbopol 971) showed sustained release over a period of 8 h follows, first order mechanism.