Delayed Release Pharmaceutical Pellets having Duloxetine Hydrochloride Containing Core and Acid Resistant Acrylic Polymer Based Outer Layer Coat.

Abstract

The aim of this investigation was to develop a delayed release pellets dosage form of duloxetine hydrochloride. Drug loaded nuclei was prepared using powder-layering technique in a conventional coating pan. The nuclei was coated with an acid resistant acrylic polymer (Eudragit L30 D55) in a wurster coater to different thickness equivalent to theoretical polymer load 25%, 30%, 35% and 40% (w/w) on dry basis. The in vitro dissolution studies were conducted in 0.1 N HCl (pH»1.1) for 2 hours followed by phosphate buffer (pH»6.8) for 1 hour with USP dissolution tester (Type-II). Enteric coated pellets with polymer load 25% and 30% failed to provide required acid resistant to the pellets but very insignificant amount of drug was leached from the coated pellets in acid phase with polymer load 35% and 40%  in the acidic phase whereas almost the whole amount of drug was released in the buffer phase. The results generated in this study showed that proper selection of polymeric materials based on their physicochemical properties as well as polymer load is important in designing delayed release pellets dosage form with acceptable dissolution profile.

KEY WORDS: Eudragit L30 D 55, Duloxetine hydrochloride, enteric coating, pellets, powder layering.