Design and Evaluation of Microcapsules of Sibutramine Hydrochloride Monohydrate

Abstract

In this paper, sibutramine hydrochloride monohydrate was formulated in the form of microcapsules in lieu of conventional tablet dosage form available to achieve its slower release rate and reduce the possible side effects of dry mouth, anorexia, insomnia, constipation and headache using ionotropic gel entrapment method with different ratio of biodegradable polymethacrylate polymers Eudragit RS-100 and RL-100. There was significant increase in half-life from 1.1-5.0 h. with entrapment up to 88 %. The physicochemical studies like bulk density, tapped density, carr's index confirmed free flowing natures of the granules. FTIR studies showed no interaction between drugs and polymer. SEM studies confirmed smooth topography of microcapsules. The in vitro dissolution studies showed maximum release of 82 % for best formulated batch B2 (1:2 drug polymer ratio) out of 5 batches B1, B2, B3, B4 and B5. The release was controlled upto 11 h. The release pattern was diffusion rate controlled and followed Higuchi pattern.