PT - JOURNAL ARTICLE AU - Rubio, F AU - Jensen, B K AU - Henderson, L AU - Garland, W A AU - Szuna, A AU - Town, C TI - Disposition of [14C]acitretin in humans following oral administration. DP - 1994 Mar 01 TA - Drug Metabolism and Disposition PG - 211--215 VI - 22 IP - 2 4099 - http://dmd.aspetjournals.org/content/22/2/211.short 4100 - http://dmd.aspetjournals.org/content/22/2/211.full SO - Drug Metab Dispos1994 Mar 01; 22 AB - The disposition of the antipsoriatic agent, acitretin, was investigated in six healthy human volunteers who each received a single, oral 50 mg dose of [14C]acitretin (50 microCi). plasma, urine, and feces were collected for 240 hr after administration. Mean values of 20.9 and 62.6% of the administered dose were recovered in the urine and feces, respectively. The terminal elimination half-life of total radioactivity from the plasma was approximately 120 hr. Extraction of pooled plasma samples followed by separation by HPLC and quantitation by liquid scintillation counting indicated that acitretin and its 13-cis-isomer, isoacitretin, were minor fractions of the total drug-related material in the plasma at most time points up to 72-hr postdose. The structures of acitretin, isoacitretin, and two other metabolites--(5E,7E)-8-(4-methoxy,2,3,6-trimethylphenyl)-2,6 -dimethyl-5,7- octadienoic acid (I) and (5E,7E)-8-(4-hydroxy-2,3,6-trimethylphenyl)-2,6-dimethyl-5,7 -octadienoic acid (II)--were confirmed by MS and cochromatography with authentic standards. I and II were major fractions of the drug-related material in the plasma at all time points. Other compounds, whose structures could not be confirmed, also account for a significant fraction of the circulating radioactivity.