FORMULATION DEVELOPMENT AND EVALUATION OF BUCCAL FILMS OF CARVEDILOL

Carvedilol is used for hypertension, angina pectoris and in symptomatic heart failure. It has a short half life of 2h and bioavailability of 25%. Therefore the present investigation is concerned with the development of the buco-mucoadhesive films, which were designed to prolong the buccal residence time, to increase penetration through buccal mucosa and thus increase the bioavailability and its half life. Various formulations were developed by using release rate controlling film forming polymers like Eudragit RL-100, PVP, HPMC, NaCMC and Carbopol 934 in various combinations by solvent casting technique using plasticizer propylene glycol with and without penetration enhancers like DMSO, Tween 60 and castor oil. For unidirectional release, backing layer using ethyl cellulose 10% w/v in ethanol incorporated with propylene glycol as a plasticizer was casted on the films. The most satisfactory formulations had retained on buccal cavity for maximum duration of 10h, released for longer duration of dissolution beyond 12h which had maximum drug permeated during ex-vivo studies. During ex-vivo diffusion studies contributed formulation consisting DMSO as penetration enhancer which increase the drug permeability through buccal mucosa up to 15% was nominated as best formulation. The most satisfactory formulation followed zero order kinetics while the drug release mechanism was found to be anomalous diffusion confirmed by Scanning Electron Microscopy. The most satisfactory formulations showed no significant changes in the physicochemical parameters, in-vitro release pattern and ex-vivo diffusion studies during stability studies for two months.