[Transdermal administration of drugs. XI. Formulation of polymeric matrices with metoprolol in transdermal therapeutic systems].

The paper is concerned with formulation studies of the transdermal therapeutic system of the matrix type with beta-adrenolytic drug metoprolol. The base of the hydrophobic matrix is the biocompatible polymer-silicone rubber, and the hydrophilic matrix was prepared from the polyacrylate polymer of the Eudragit type. The properties of the silicone matrix were modified by the additive Methocel F 4M, macrogol 600, copolymer p (HEMA) with methacrylic acid and polyacrylamide. The matrices were evaluated on the basis of the results of in vitro liberation of the drug at 32 degrees C. The liberation profiles of metoprolol were evaluated by means of the parameters of Tornquist hyperbolic function calculated by nonlinear regression. Of the composite ingredients of the silicone matrix, Methocel F 4M proved to be the best. Metoprolol was released most from the hydrophilic matrix prepared from Eudragit NE 30D. It released 12.32 mg.cm(-2).24 h-1 of metoprolol.