title: Reexamination of pharmacokinetics of oral testosterone undecanoate in hypogonadal men with a new self-emulsifying formulation.
abstract: Many hypogonadal men prefer oral testosterone (T) treatment. Oral T  undecanoate (TU) is available in many countries, but not in the United States.  We aimed to assess the pharmacokinetics of oral TU in a new self-emulsifying  drug delivery system formulation. Pharmacokinetics studies were conducted in 3  parts: 12 hypogonadal men were enrolled in 2 centers for a 1-day dosing study;  29 participants were enrolled from 3 centers for a 7-day dosing study; and 15  participants were enrolled from 1 center for a 28-day dosing study. Serial  blood samples for serum sex hormone measurements by liquid  chromatography-tandem mass spectrometry were drawn for up to 36 hours  after oral TU administration. Mean serum T levels (C(avg)) after oral  dosing of T 200 mg as TU twice daily with food were within the adult male  range in most participants in the 1-, 7-, and 28-day dosing studies but were  much lower in the fasting state. The dose-proportional increase in  C(avg) of serum T after oral T 300 mg twice daily resulted in more  participants with supraphysiologic serum T levels. In the 28-day study, trough  serum T reached a steady state at day 7. Serum dihydrotestosterone and  estradiol levels tracked serum T concentration.  Dihydrotestosterone-testosterone ratios increased 3-fold after oral TU  administration. Oral T 200 mg twice daily as TU in a new SEDDS formulation may  be a viable therapy for hypogonadal men.
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Anthony Y
authors.initials: AY
authors.lastname: Yin
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Michelle
authors.initials: M
authors.lastname: Htun
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Swerdloff
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Maruja
authors.initials: M
authors.lastname: Diaz-Arjonilla
authors.affiliation: Clarus Therapeutics Inc, Northbrook, Illinois.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Dudley
authors.affiliation: Clarus Therapeutics Inc, Northbrook, Illinois.
authors.forename: Sandra
authors.initials: S
authors.lastname: Faulkner
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Rachelle
authors.initials: R
authors.lastname: Bross
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Andrew
authors.initials: A
authors.lastname: Leung
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Sima
authors.initials: S
authors.lastname: Baravarian
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Laura
authors.initials: L
authors.lastname: Hull
authors.affiliation: Clarus Therapeutics Inc, Northbrook, Illinois.
authors.forename: James A
authors.initials: JA
authors.lastname: Longstreth
authors.affiliation: Alabama Internal Medicine, Birmingham, Alabama.
authors.forename: Steven
authors.initials: S
authors.lastname: Kulback
authors.affiliation: Alabama Clinical Therapeutics, Birmingham, Alabama.
authors.forename: Gregory
authors.initials: G
authors.lastname: Flippo
authors.affiliation: Department of Medicine, Division of Endocrinology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California.
authors.forename: Christina
authors.initials: C
authors.lastname: Wang
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000728:Androgens / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D001711:Biotransformation; D002853:Chromatography, Liquid; D018592:Cross-Over Studies; D013196:Dihydrotestosterone / Q000097:blood; D004334:Drug Administration Schedule; D004655:Emulsions; D004958:Estradiol / Q000097:blood; D005215:Fasting / Q000097:blood; D018565:Food-Drug Interactions; D006801:Humans; D007006:Hypogonadism / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D053719:Tandem Mass Spectrometry; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D016896:Treatment Outcome; D014481:United States
chemical_list: D000728:Androgens; D004655:Emulsions; D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol; C010792:testosterone undecanoate