Design & Development of Modified Release Venlafaxine HCl Capsules

Abstract

The purpose of this research work was to develop venlafaxine hydrochloride capsules for obtaining zero order drug release. Granules were prepared by wet granulation technique using combination of ethyl cellulose & hydrophilic polymers and were filled into hard gelatine capsule. The in-vitro dissolution study was performed in distilled water. Capsule containing ethyl cellulose and hypromellose were coated by different ratio of ethyl cellulose and dibutyl phthalate at different levels. 32 full factorial design was applied for optimization of the formulation, f1 & f2 values were calculated between optimized release profile and proposed release. Kinetics of drug release was studied and the dissolution of the optimized batch was carried out in 0.1N HCl and phosphate buffer. Burst drug release was exhibited by the uncoated capsules, probably due to high aqueous solubility of the venlafaxine hydrochloride, the coated capsules showed sustained drug release without burst effect. The optimized batch showed similarity with the proposed release profile, the drug release was best explained by zero order release model. The optimized batch showed identical drug release in 0.1 N HCl and phosphate buffer. this study demonstrate the utility of sustained release formulation to sustain the in-vitro release of highly water soluble drugs