Development and Evaluation of Diltiazem Hydrochloride Transdermal Patches by Using Glycerol and Castor Oil as Plasticizers

In this study, matrix-type transdermal patches containing Diltiazem hydrochloride were prepared using ethyl cellulose (EC) by solvent evaporation technique using 20%, 30%, 40% of glycerol and 20%,30%,40% of castor oil incorporated as plasticizer. The drug matrix film of EC was casted on a polyvinylalcohol backing membrane that was previously dried at 60°C for 6 hrs. All the prepared formulations were subjected to physical studies (moisture content, moisture uptake, Tensile strength, flatness and Drug content determination), in vitro release studies and in vitro skin permeation studies. The physiochemical compatibility of the drug and the polymers studied by infrared spectroscopy suggested absence of any incompatibility. In vitro permeation studies were performed across cadaver skin using a Franz diffusion cell. Variations in drug release profiles among the formulations studied were observed. The Optimized formulation containing ethyl cellulose and 40% of glycerol as a plasticizer showed 86.21% drug release after 24 hours.