title: Pharmacokinetics and bioavailability of a new testosterone gel formulation in comparison to Testogel® in healthy men.
abstract: This randomized, open-label, multiple-dose three-way cross-over study compared the pharmacokinetics of a new testosterone gel formulation in two strengths, testosterone gel 1% and testosterone gel 2% (FE 999303), with Testogel® in 11 testosterone-suppressed healthy men. Subjects received one of six treatment sequences; 50 mg of testosterone was administered once daily for 7 consecutive days, with different treatments separated by washout-periods of 6-9 days. Testosterone gel 1% and testosterone gel 2% displayed greater relative bioavailability (2.6- and 1.6-fold, respectively) than Testogel on Day 1, which persisted, to a smaller extent, on Day 7. Initial absorption was highest and most rapid for testosterone gel 1% and 2%, showing apparent first-order absorption kinetics. Maximum serum concentrations (Cmax ) were 6.25 and 2.97 ng/mL, respectively, occurring ∼5-6 hours post-application on Day 1 versus Cmax of 1.71 ng/mL after ∼24 hours with Testogel, showing apparent zero-order absorption kinetics. Similar differences were observed on Day 7. All treatments appeared to reach approximately the same steady-state level within the first 24 hours. No application-site skin reactions occurred with any preparation. In conclusion, the new testosterone formulation showed higher bioavailability, and the ability to deliver more testosterone in a smaller volume.
authors.affiliation: Ferring Pharmaceuticals A/S, Experimental Medicine, Copenhagen, Denmark.
authors.forename: Håkan
authors.initials: H
authors.lastname: Olsson
authors.affiliation: Ferring Pharmaceuticals A/S, Experimental Medicine, Copenhagen, Denmark.
authors.forename: Rikard
authors.initials: R
authors.lastname: Sandström
authors.affiliation: Ferring Pharmaceuticals A/S, Urology and Endocrinology, Copenhagen, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Neijber
authors.affiliation: Ferring Galenisches Labor AG, Allschwill, Switzerland.
authors.forename: Dario
authors.initials: D
authors.lastname: Carrara
authors.affiliation: Ferring Pharmaceuticals A/S, Experimental Medicine, Copenhagen, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Grundemar
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D001682:Biological Availability; D018592:Cross-Over Studies; D004334:Drug Administration Schedule; D004339:Drug Compounding; D005782:Gels; D005858:Germany; D006207:Half-Life; D064368:Healthy Volunteers; D020249:Hormone Replacement Therapy; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D012869:Skin Absorption; D013739:Testosterone / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics*; D013810:Therapeutic Equivalency; D055815:Young Adult
chemical_list: D005782:Gels; D013739:Testosterone
keywords: bioavailability; dihydrotestosterone; gel; pharmacokinetics; testosterone