In Vitro and In Vivo Evaluation of a Novel Nonscrotal Matrix-Type Transdermal Delivery System of Testosterone

Abstract

A matrix-type testosterone (TS) transdermal delivery system for nonscrotal skin was developed with DuroTak 87-2510 as an adhesive polymer. When 3% dodecylamine was used in combination with 10% span 80, the in vitro rat permeation rate increased from 2.29 microg/cm2/hr to 6.51 microg/cm2/ hr as the TS loading dose increased from 2% to 6%. The maximum flux of experimental patch was about 14-fold higher than that of Testoderm. Release kinetics of TS from the patches was proportional to t1/2 following the Higuchi equation, and the release rate of TS increased as TS loading dose increased. Also, a good linear relationship between the skin permeation rate and the release rate was observed, which implies that the release rate is the rate-limiting process of the skin permeation. In vivo study showed that the plasma concentration of TS promptly increased and reached the peak level within 3-6 hours of application of the experimental patch. Area under the curve (AUC0 approximately 48) and Cmax also linearly increased in a dose-dependent manner up to 6% of TS. These results demonstrate the feasibility of developing a nonscrotal matrix-type transdermal delivery system of TS.