Abstract

Ophthalmic inserts of tetracycline HCI were prepared as membrane permeation controlled devices with the aim of achieving once a day administration. Drug reservoir and rate controlling membrane were prepared using different hydrophilic polymers such as HPMC, MC, PVP (K-30) and hydrophobic ethyl cellulose respectively. The ocular inserts were evaluated for their physico chemical properties, in vitro kinetics, and in vivo release characteristics. Since, the targeted zero order mode of release was observed in formulation F6 (Drug reservoir with 2% HPMC and 4% EC as rate controlling membrane), its in vivo release characteristics were evaluated using rabbits as animal models. Influence of changes in polymer composition of films over physical and in vitro release characteristics were tested using statistical tools such as ANOVA and the Students t-test. The in vitro release kinetic data was treated according to diffusion models proposed by Higuchi and Peppas in order to access the mechanism of drug release.