Kinetics of plasma and tissue distribution of 9-cis-retinoic acid in rat.

The biotransformation and tissue distribution of 9-cis-retinoic acid was investigated in hairless rats. Indeed, only limited information is available about the pharmacokinetics of 9-cis-retinoic acid. Assuming that the target site for retinoids is the skin, tissue distribution study is therefore particularly justified. Following single oral administration of 30 mg/kg of 9-cis-retinoic acid, the parent drug and five metabolites were detected in plasma. Additionally, concentrations of 9-cis-retinoic acid and metabolites were determined in the skin and seven other tissues. The distribution of 9-cis-retinoic acid was rapid in all of the organs studied (T(max) </=2 h). In skin, unchanged 9-cis-retinoic acid was still measurable up to 168 h after administration and was undetectable in other organs and plasma after 48 h. Copyright 2000 S. Karger AG, Basel