Pharmacokinetics and biliary excretion of osaterone acetate, a new steroidal antiandrogen, in dogs.
The pharmacokinetics and biliary excretion of osaterone acetate (17alpha-acetoxy-6-chloro-2-oxa-4,6-pregnadiene-3,20-dione; OA), a new steroidal antiandrogen, were investigated in intact dogs and biliary fistula dogs after bolus intravenous administration of (14)C-labeled drug. In intact dogs, OA exhibited a biexponential disposition with a very long half-life of 197.9 +/- 109.9 h. OA accounted for almost all the plasma radioactivity. The major route of excretion was in feces via the bile. One-third of the radioactivity in the bile was due to OA. The major biliary metabolite was identified as a glucuronide of 17alpha-acetoxy-6-chloro-21-hydroxy-2-oxa-4,6-pregnadiene-3,20-dione. A significant amount of biliary recycling occurs in dogs.
Minato
Kouichi
K
Pharmacokinetics Research Department, Teikoku Hormone Manufacturing Company, Takatsu-ku, Kawasaki-shi, Kanagawa, Japan. minato-k@kw.teikoku-hormone.co.jp
Koizumi
Naoyuki
N
Honma
Seijirou
S
Tsukamoto
Kunio
K
Iwamura
Satoshi
S
D000726:Androgen Antagonists / Q000737:chemistry / Q000493:pharmacokinetics*; D000818:Animals; D001646:Bile / Q000378:metabolism*; D002715:Chlormadinone Acetate / Q000031:analogs & derivatives / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics*; D002855:Chromatography, Thin Layer; D004285:Dogs; D005260:Female; D008297:Male; D019906:Nuclear Magnetic Resonance, Biomolecular
D000726:Androgen Antagonists; D002715:Chlormadinone Acetate; C069297:osaterone acetate