Pharmacokinetics of a new testosterone transdermal delivery system, TDS®-testosterone in healthy males

Abstract

Aims: The Transdermal Delivery System (TDS®) is a liquid formulation that can be applied to the skin via a metered pump spray to deliver drug to the systemic circulation. The aims of this study were to assess the ability of the TDS® preparation to deliver testosterone systemically, and to characterize the pharmacokinetic profiles of the hormone in healthy males. Methods: An open label, comparative, randomized placebo controlled study involving three treatments and three periods with a minimum of a 1 week washout period was conducted. Twelve healthy males received 50 mg TDS®-testosterone, TDS®-placebo, and 50 mg of a commercially available topical testosterone preparation (Androgel ®, 1% topical testosterone gel). Results: The mean AUC(0,12 h) was higher following application of TDS®-testosterone (61.8 ng ml-1 h), compared with Androgel® (57.7 ng ml -1 h) and TDS®-placebo (50.7 ng ml-1 h. The mean Cmax (0,12 h) was similar for TDS®-testosterone (6.6 ng ml-1) and Androgel® (6.5 ng ml-1) and these values were higher than those for TDS®-placebo (5.7 ng ml-1). Analysis of variance showed that the 90% confidence intervals on the relative difference of the ratio for the AUC(0,12 h) and the C max (0,12 h) between TDS®-testosterone and Androgel®, were contained within the bioequivalence limit (80, 125%) (Cmax 89.2, 112.3% and AUC 93.5, 120.5%). Serum testosterone concentrations were lower following TDS®-Placebo and were not bioequivalent either to the gel or spray. Conclusions: The TDS® preparation was shown to deliver testosterone systemically to humans and the concentrations of the hormone in the 12 h following TDS® administration were bioequivalent to an existing topical delivery gel. © 2005 Blackwell Publishing Ltd.