Evaluation of the pharmacokinetic profiles of the new testosterone topical gel formulation, Testim, compared to AndroGel.

A two-period, randomized, complete crossover study was performed to evaluate the pharmacokinetic profiles of Testim (AA2500), a new 1% testosterone topical gel formulation, compared to AndroGel, an already available 1% testosterone topical gel. Twenty-nine hypogonadal subjects received a single dose (50 mg testosterone) of each formulation seven days apart. C(max) estimates for total testosterone, dihydrotestosterone and free testosterone were greater (30, 19 and 38%, respectively) following the application of Testim compared to AndroGel. Similarly, AUC(0-24) estimates for total testosterone, dihydrotestosterone, and free testosterone were greater (30, 11 and 47%, respectively) following the application of Testim compared to AndroGel. Confidence intervals for C(max) and AUC(0-24) were not wholly contained within the bioequivalence limits for testosterone, therefore Testim trade mark and AndroGel are not bioequivalent with Testim providing higher serum levels and greater bioavailability than AndroGel.