title: Biotransformation and mass balance of tipranavir, a nonpeptidic protease inhibitor, when co-administered with ritonavir in Sprague-Dawley rats.
abstract: In this study, tipranavir (TPV) biotransformation and disposition when co-administered with ritonavir (RTV) were characterized in Sprague-Dawley rats. Rats were administered a single intravenous (5 mg kg(-1)) or oral (10 mg kg(-1)) dose of [(14)C]TPV with co-administration of RTV (10 mg kg(-1)). Blood, urine, faeces and bile samples were collected at specified time-points over a period of 168 h. Absorption of TPV-related radioactivity ranged from 53.2-59.6%. Faecal excretion was on average 86.7% and 82.4% (intravenous) and 75.0% and 82.0% (oral) of dosed radioactivity in males and females, respectively. Urinary excretion was on average 4.06% and 6.73% (intravenous) and 9.71% and 8.28% (oral) of dosed radioactivity in males and females, respectively. In bile-duct-cannulated rats, 39.8% of the dose was recovered in bile. After oral administration, unchanged TPV accounted for the majority of the radioactivity in plasma (85.7-96.3%), faeces (71.8-80.1%) and urine (33.3-62.3%). The most abundant metabolite in faeces was an oxidation metabolite R-2 (5.9-7.4% of faecal radioactivity, 4.4-6.1% of dose). In urine, no single metabolite was found to be significant, and comprised <1% of dose. TPV when co-administered with RTV to rats was mainly excreted in feces via bile and the parent compound was the major component in plasma and faeces.
authors: Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT 06877, USA. smacha@rdg.boehringeringelheim.com
authors: Sreeraj
authors: S
authors: Macha
authors: Linzhi
authors: L
authors: Chen
authors: Stephen H
authors: SH
authors: Norris
authors: Elsy
authors: E
authors: Philip
authors: Yanping
authors: Y
authors: Mao
authors: Helga
authors: H
authors: Silverstein
authors: Craig
authors: C
authors: Struble
authors: Wendy
authors: W
authors: Beers
mesh_terms: D000042:Absorption; D000284:Administration, Oral; D000818:Animals; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001646:Bile / Q000378:metabolism; D001711:Biotransformation; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D010084:Oxidation-Reduction; D011725:Pyridines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011753:Pyrones / Q000008:administration & dosage / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019438:Ritonavir / Q000494:pharmacology*; D012737:Sex Factors; D013449:Sulfonamides; D014018:Tissue Distribution
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D011725:Pyridines; D011753:Pyrones; D013449:Sulfonamides; D019438:Ritonavir; C107201:tipranavir