TRANSDERMAL TESTOSTERONE ADMINISTRATION IN HYPOGONADAL MEN - COMPARISON OF PHARMACOKINETICS AT DIFFERENT SITES OF APPLICATION AND AT THE FIRST AND 5TH DAYS OF APPLICATION

In this study of 13 hypogonadal men (25-69 years of age), three open-l abel, randomized treatments were administered to determine the pharmac okinetics of serum testosterone after application of an investigationa l testosterone transdermal system to the upper buttocks, upper arm, an d back. Testosterone in vivo input kinetics profiles were estimated by DeMonS, a recently developed numerical deconvolution method for estim ating drug absorption at different time intervals and/or drug disposit ion model parameters, and compared on the first and fifth days of syst em application. Area under the concentration-time curve from 0 to 27 h ours (AUC(0-27)) values for testosterone after one-day applications to the upper buttocks, upper arm, and back were 9,560 ng . hr/dL, 8,651 ng . hr/dL, and 8,988 ng . hr/dL, respectively. Maximum observed conce ntration (C-max) values were 482 ng/dL, 462 ng/dL, and 499 ng/dL, resp ectively. Serum testosterone concentrations were equivalent to each ot her, and C-max values fell within the normal range. No drug accumulati on was seen with repeated dosing over 5 days.