Preparation and Statistical Optimization of Alginate Based Stomach Specific Floating Microcapsules of an Antihypertensive Agent

Abstract

The present study involves preparation and characterization of floating microcapsules with Simvastatin as model drug for prolongation of gastric residence time. The main objective of this work is to improve solubility of simvastatin  b-cyclodextrin complex (1:2) by co-precipitation method and then to deliver the same in sustained release dosage form. Sustained-release simvastatin microcapsules were prepared by the ionic gelation technique, using carbopol-941 as swellable floating polymer. A 3³ full factorial design was used to study the effect of polymer concentration, drug complex and sodium alginate. The formed microcapsules were subjected to various evaluation tests such as drug encapsulation efficiency, in vitro drug release and surface morphology was studies using SEM. Powdered X-ray diffractometer and FTIR were used to investigate the complexation of simvastatin in the microcapsules. As the carbopol 941 is self swellable polymer, immediate floating was observed. The in vitro release studies and floating behaviour were performed in HCl buffer pH 1.2. The best fit release kinetics was achieved with first order release. It was concluded from the present investigation that porous carbopol 941 microcapsules are promising sustained release as well as stomach specific carriers for delivery of simvastatin.