Formulation and Evaluation of Eudragit Rl100 Polymeric Drug Loaded Microsponge for Ophthalmic Use

Aims: The aim of this work is the formulation of Eudragit RL100 polymeric microsponges. The Microsponge Delivery System is a patented technique in which there is a polymeric system consisting of porous particles.

Methodology: The ratio of Diclofenac sodium and eudragit RL100 varied from 1:1 to 13: 1 to formulate microsponge. Dichloromethane was used as internal phase and polyvinylalcohol was used as an external phase. The formed microsponges were characterized for particle size, entrapment efficiency, drug content, in vitro drug release and SEM.

Results: With increase in drug: polymer ratio there is increase in production yield from 20.04% to 72.14%, and entrapment efficiency from 20.11% to 70.77%. Drug content of formed microsponge varied between 50.18% to 91.09% whereas particle size ranged from 1.41 µm to 17.66 µm. Microsponge formulations F3, F4 and F5 showed desired particle size hence studied for further evaluation. Formulation F3, F4 and F5 showed controlled release of 89.54%, 98.5% and 98.76% respectively up to 6 hr. F3 showed more controlled release at the end of 6 hr. The drug release from microsponges was best fitted to Higuchi’s diffusion kinetics for all microsponge formulations with non-Fickian diffusion mechanism. The formed microsponge particles have spherical porous structure.

Conclusion: Study showed significance of Microsponge Delivery System for ophthalmic administration.