Formulation, characterization and evaluation of bioadhesive buccal patch of venlafaxine

Abstract

The present study involves the formulation and evaluation of buccal patches of venlafaxine using different polymers like Ethyl cellulose, Hydroxypropyl methylcellulose (HPMC) K4M, Eudragit S100 in various proportion and combination, where propylene glycol and dibutylpthalate are used as plasticizer. All formulations are formulated by solvent casting technique. Venlafaxine; an antidepressant drug has high first pass metabolism so buccal route is excellent for its systemic delivery thereby rendering great bioavailability. Preformulation studies were conducted before formulation and formulated patches were subjected for evaluation of various physicochemical parameters like thickness, wt. uniformity, pH, content uniformity, folding endurance, percentage swelling, tensile strength, vapour transmission rate, percentage moisture loss and muco-adhesion force. In vitro drug release study was carried out using Franz diffusion cell. From among all the developed formulations, the formulations FP4, FP7 and FP14 provide a well-controlled release of drugs so these were selected as the best formulations. The optimized fabricated patches were sustained for more than 10 h and obeyed Higuchi kinetics  and mechanism of release was  fickian diffusion. Optimized patches were also subjected to ex vivo study using Goat buccal mucosa. The experimental result revealed that there was no significant difference between ex vivo and in vitro release profile.