COMPARATIVE EVALUATION OF POLYMER COMBINATION IN THE DESIGN OF BRIMONIDINETARTRATE OCULAR INSERTS

Brimonidine is an anti-glaucoma agent useful in treatment of intraocular pressure. In the present study an attempt was made to formulate ophthalmic inserts of brimonidine tartrate (BT) in combination withpolymers like methylcellulose, carboxymethyl chitosan and HPMC. Prepared ocular films were evaluatedfor uniformity in thickness, weight variation, % moisture absorption, % moisture loss, in vitro and invivo release studies. The physical characteristics of the films were found to be within acceptable limits.The study confirmed that brimonidine tartrate can be delivered through films made of methyl cellulose,carboxymethyl chitosan and HPMC combination matrix cast with ethyl cellulose (EC). In vitro release study revealed that increasing the proportion of polymer concentration decreased the rate of release of brimonidine tartrate. In vivo release profile of ocular inserts revealed controlled release of drug over aperiod of 24 h. Optimized formulation CH3 was evaluated for in vivo release characteristics using rabbits as animal model. The optimized formulation CH3 was found to be stable at accelerated storage condition of 40/75 % RH.