Food increases the bioavailability of acitretin.

Eighteen healthy male volunteers received 50 mg oral doses of acitretin on two occasions, according to a random crossover design. Acitretin was administered during a complete fast or following a moderate breakfast. Plasma samples were obtained at various times and the concentration of acitretin and its 13-cis isomeric metabolite (Ro 13-7652) were quantified by a specific HPLC assay. The AUC0-15 for acitretin was increased when administered with food for all subjects (except one) with a mean increase of 90% (from 1175 to 2249 ng/ml.hr). The maximum plasma concentration of acitretin (Cmax) was increased by 70% when administered with food (from 245 to 416 ng/ml), while the time to reach Cmax was unaffected. The ratio of AUC of Ro 13-7652 to acitretin was the same for both the fasted and fed conditions; therefore, the formation of metabolite was not influenced by concomitant ingestion of food. The presence of food increases the apparent bioavailability of acitretin. A likely mechanism behind this observation is an increase in acitretin solubility in addition to an increase in the lymphatic absorption and a prolonged residence time of the drug in the gastrointestinal tract.