A Comparison of a Novel Testosterone Bioadhesive Buccal System, Striant, with a Testosterone Adhesive Patch in Hypogonadal Males

Abstract

A novel delivery system has been developed for testosterone replacement. This formulation, COL-1621 (Striant), a testosterone-containing buccal mucoadhesive system, has been shown in preliminary studies to replace testosterone at physiological levels when used twice daily. Therefore, the current study compared the steady-state pharmacokinetics and tolerability of the buccal system with a testosterone-containing skin patch (Andropatch or Androderm) in an international multicenter study of a group of hypogonadal men. Sixty-six patients were randomized into two groups; one applied the buccal system twice daily, whereas the other applied the transdermal patch daily, in each case for 7 d. Serum total testosterone and dihydrotestosterone concentrations were measured at d 1, 3 or 4, and 6, and serially over the last 24 h of the study. Pharmacokinetic parameters for each formulation were calculated, and the two groups were compared. The tolerability of both formulations was also evaluated. Thirty-three patients were treated with the buccal preparation, and 34 were treated with the transdermal patch. The average serum testosterone concentration over 24 h showed a mean of 18.74 nmol/liter (SD = 5.90) in the buccal system group and 12.15 nmol/liter (SD = 5.55) in the transdermal patch group (P < 0.01). Of the patients treated with the buccal system, 97% had average steady-state testosterone concentrations within the physiological range (10.41-36.44 nmol/liter), whereas only 56% of the transdermal patch patients achieved physiological total testosterone concentrations (P < 0.001 between groups). Testosterone concentrations were within the physiological range in the buccal system group for a significantly greater portion of the 24-h treatment period than in the transdermal patch group (mean, 84.9% vs. 54.9%; P < 0.001). Testosterone/dihydrotestosterone ratios were physiological and similar in both groups. Few patients experienced major adverse effects from either treatment. No significant local tolerability problems were noted with the buccal system, other than a single patient withdrawal. We conclude that this buccal system is superior to the transdermal patch in achieving testosterone concentrations within the normal range. It may, therefore, be a valuable addition to the range of choices for testosterone replacement therapy.