The purpose of this study is to investigate in vitro release and ex vivo transdermal penetration of sotalol from monolithic films prepared by Eudragit E100 (E100) combined with Eudragit RS100 (RS100) or ethyl cellulose (EC) prepared onto a PVA backing membrane by solvent casting method. Film properties were evaluated by means of uniformity of the films, which was evidenced by the low standard deviations of thickness and drug amount studies as well as high sotalol contents. In vitro and ex vivo release studies were carried out by vertical Franz diffusion cells. Ex vivo skin penetration of drug was modified by either dimethyl sulphoxide (DMSO) or iontophoresis. Obtained results showed that films containing RS 100 polymer gave higher degrees of swelling accompanied with higher in vitro release rates of drug that could attributed to the higher permeability of this polymer. In vitro release of drug from the films was found slower with E100 and EC combination, which best fitted to the Higuchi as well as Korsmeyer-Peppas kinetics. The skin penetration of sotalol from this film with application of 0.5 mA/cm2 direct current for three hours was found two fold higher than pre-treatment for two hours of 5 % w/w DMSO in ethanol and best fitted to Higuchi kinetic.

Keywords: Transdermal penetration, Sotalol, Eudragit, Iontophoresis, Dimethyl sulphoxide