title: Kinetics of tissue distribution and elimination of retinoid drugs in the rat. I. Acitretin.
abstract: Rats were injected with single intravenous doses of acitretin (6 mg/kg), and concentrations of the drug and its metabolite, 13-cis-acitretin, were determined in plasma and nine tissues up to 6 hr postdose. A newly developed sensitive method for the determination by HPLC of acitretin, 13-cis-acitretin, and etretinate was used. Acitretin rapidly appeared in liver and muscle, where it underwent redistribution into skin and adipose tissue. Tissue/plasma concentration ratios of acitretin ranged from 2.8 to 0.3 in the order adipose tissue > brain, liver > lung, heart, kidney, spleen > skin, muscle. Adipose tissue storage was moderate and short-lived. The metabolite, 13-cis-acitretin, was detected in all tissues but not in plasma; it accounted for < 10% of the administered dose at any time. No etretinate could be detected as a metabolite in plasma or tissues. After 6 hr, < 1% of the dose remained in the body as acitretin and 13-cis-acitretin. Disappearance was monophasic, with an elimination half-life of 70 min in plasma and 68 +/- 9 min in the nine tissues. The volume of distribution was 0.6 liters/kg and clearance 6 ml.min-1.kg-1. Acitretin was characterized by rapid first-order elimination and the absence of storage in a deep compartment.
authors.affiliation: Department of Pharmacology, University of Berne, Switzerland.
authors.forename: E U
authors.initials: EU
authors.lastname: Eisenhardt
authors.forename: M H
authors.initials: MH
authors.lastname: Bickel
mesh_terms: D017255:Acitretin / Q000097:blood / Q000493:pharmacokinetics*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D017255:Acitretin