Formulation Characterization and Evaluation of Matrix type Transdermal Patches of Carvedilol

The present study was carried out to formulate, characterize and evaluate a matrix-type transdermal formulation containing Carvedilol with different ratios of polymer (Eudragit RL100, HPMC and Ethyl Cellulose) combinations plasticized with dibutylpthalate by the solvent evaporation technique. The interference of the polymers were ruled out by infrared spectroscopy. In-vitro release study was performed using Franz diffusion cell with cellophane membrane as barrier. The prepared patches were tested for their physicochemical characteristics such as thickness, drug content uniformity, Percentage moisture uptake and folding endurance. In-vitro release studies of Carvedilol-loaded patches in phosphate buffer saline of pH 7.4 exhibited drug release in the range of 52% to 81% in 24h for the formulations F1-F6. The in-vitro drug permeability studies of optimized formulation F1 was found to be 48.67 μg/cm²/hr. Data of in vitro release from patches were fit in to different equations and kinetic models to explain release kinetics. The release of Carvedilol from the optimized formulation F1 follows zero order kinetics and the mechanism of drug release was concluded as diffusion controlled. The developed transdermal patches increase the efficacy of Carvedilol for the therapy of hypertension.