Formulation and evaluation of dapsone loaded microsphere incorporated gel delivery system

Abstract

The present study was aimed to control and prolong the release of Dapsone by formulating and microspheres and incorporating in to gel dosage form for topical application with a reduced frequency of application and hence lesser known side effects. The microspheres were prepared using suspension polymerization method. An increase in concentration of the polymer was found to increase the particle size along with the amount of entrapped drug. The surface of the microspheres was found to be smooth. In vitro drug release of microspheres exhibited a biphasic release pattern with an initial burst release effect. The release kinetics data best fitted with first order kinetics and the Higuchi matrix data was able to explain the controlled release of drug from the microspheres. The gel formulations made from the microspheres (DM4, (drug: polymer, 1:4)) possessed all the physicochemical evaluation parameters within acceptable limits. The in vitro diffusion data made it evident that the gel formulation with 1.0% HPMC, loaded with DM4 was able to release about 68% drug at the end of 24 hours.