title: [Pharmacokinetics of epristeride in rats and beagle dogs].
abstract: OBJECTIVE
  To study the pharmacokinetics of epristeride (EPR) in rats and Beagle dogs.
  
  
  METHODS
  The concentrations of EPR in biological samples were determined by an HPLC method with UV detection.
  
  
  RESULTS
  The concentration-time curves in rat serum showed two peak concentrations after i.g. doses of 10, 20 and 40 mg.kg-1. The Tpeak1 and Tpeak2 were attained within 0.5-1 h and 3-4 h, respectively. The elimination half-life(T1/2 beta) was 2.43-3.14 h. The Tpeak and T1/2 beta in Beagle dogs were 1 h and 5 h, respectively. EPR was shown to be widely distributed to various tissues after i.g. dose of 20 mg.kg-1. The concentrations in most tissues at 3 h were higher than those of 6 h. The excretion of parent drug in urine amounted to only 0.09% of the dosage and in feces to 42.9% within 24 h after dosing. The biliary excretion were mainly metabolites and only 0.14% of parent drug of the dosage within 12 h. Plasma protein binding ratio of EPR was 92.3% at the concentration range of 50-3,000 ng.mL-1.
  
  
  CONCLUSIONS
  The absorption of EPR was shown to be of first order processes at doses of 10-40 mg.kg-1, both the Cmax and AUC increased proportionally with the dosages. EPR was shown to be widely distributed to the various tissues and mainly eliminated via the feces and bile.
authors.affiliation: Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
authors.forename: G L
authors.initials: GL
authors.lastname: Wei
authors.forename: S H
authors.initials: SH
authors.lastname: Xiao
authors.forename: C X
authors.initials: CX
authors.lastname: Liu
mesh_terms: D000730:Androstadienes / Q000493:pharmacokinetics*; D000818:Animals; D004285:Dogs; D006207:Half-Life; D008297:Male; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
chemical_list: D000730:Androstadienes; C072547:epristeride