FORMULATION AND EVALUATION OF CONTROLLED RELEASE TABLETS OF MIGLITOL USING HYDROPHOBIC POLYMERS

Abstract

In the present study, miglitol 25 mg controlled release matrices were prepared by direct compression and in vitro drug dissolution studies were performed to find out the drug release rate and patterns. Hydroxypropyl methylcellulose phthalate (HPMCP), polyvinyl acetate (PVA) and their combination were used as rate controlling polymers. Effects of addition of hydroxypropyl methylcellulose phthalate and polyvinyl acetate on in-vitro drug dissolution were studied.  Tablets were formulated using total polymer content as 20, 30 and 40 percent. In-vitro drug release was carried out using USP Type II at 50 rpm in 900 ml of acidic dissolution medium (pH 1.2) for 2 hours, followed by 900 ml alkaline dissolution medium (pH 7.4) up to 12 hours. Mean dissolution time is used to characterize drug release rate from a dosage form and indicates the drug release retarding efficiency of polymer. When hydroxypropyl methylcellulose phthalate and polyvinyl acetate were used alone as the only retarding polymer, retardation effect increased proportionately as the concentration of polymer increased; however lacked the desirable physical properties. Combination in the matrix gave both the retardation effect as well as desired physical properties to the formulation. Several kinetic models were applied to the dissolution profiles to determine the drug release kinetics.

KEYWORDS: Miglitol, Hydroxypropyl methylcellulose phthalate, Polyvinyl Acetate, Release Kinetics.