Polyurethanes as self adhesive matrix for the transdermal drug delivery of testosterone.

The new technology to manufacture transdermal active patches without solvents or increased temperatures described here is based on polyol and isocyanate reacting to polyurethane (PU) in the presence of the drug. The technology was proven using testosterone (T) as the drug and N,N-Diethyl-m-toluamide (DEET) and Limonene (L) as enhancers for skin permeation. The experimental patches varied in drug content and enhancer concentration. The patches were evaluated regarding adhesion to stainless steel or leather, in vitro drug release and T permeation across human cadaver skin using Franz cell. Comparing the results with those of a parallel investigation of the commercial product, Testopatch(®), adhesion to leather and in vitro drug release of the experimental patches were found to be higher. The steady-state flux (J(SS)) of T from the experimental patches was found lower than Testopatch(®). The flux of the experimental patch P3, which had the highest concentration of DEET and a low concentration of L was comparable to J(SS) of the commercial product, Testopatch(®).