Original Articles: 2011 Vol: 3 Issue: 5
Design & Fabrication of Tramadol HCl loaded Multiparticulate Colon Targeted Drug Delivery System
Abstract
The aim of the present study is to develop a multiparticulate system containing pectin microspheres for the colon targeted delivery of Tramdol HCl (TMD) for the treatment of irritable bowel syndrome. This work combines pH-dependent solubility of shellac polymers and microbial degradability of pectin polymers. Pectin microspheres containing TMD were prepared by emulsion cross linking method using different ratios of TMD and pectin (1:2 to 1:5), stirring speeds (500-2000 rpm) and emulsifier concentrations (1.0 % - 2.0% wt/vol). The yield of preparation and the encapsulation efficiencies were high for all pectin microspheres. Microspheres prepared by using drug: polymer ratio 1:3, stirring speed 1000 rpm, and 1.25% wt/vol concentration of emulsifying agent were selected as an optimized formulation. Shellaccoating of pectin microspheres was performed by oil-in-oil solvent evaporation method using coat: core ratio (5:1). Microspheres were evaluated for surface morphology, particle size and size distribution, swellability, percentage drug entrapment, and in vitro drug release in simulated gastrointestinal fluids (SGF). The release profile of TMD from Shellac-coated pectin microspheres was pH dependent. In acidic medium, the release rate was much slower; however, the drug was released quickly at pH 7.4. It is concluded from the present investigation that Shellac-coated pectin microspheres are promising controlled release carriers for colon-targeted delivery of TMD.