Compared kinetics of 2-(2,3-dihydro-5-acetoxy-4,6,7-trimethylbenzofuranyl) acetic acid (IRFI 016) and its active metabolite 2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuranyl) acetic acid (IRFI 005) in plasma and bronchial alveolar liquid in mice.

The concentration of 2-(2,3-dihydro-5-acetoxy-4,6,7-trimethylbenzofuranyl) acetic acid (IRFI 016) and its active metabolite 2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuranyl) acetic acid (IRFI 005) in bronchial alveolar liquid (BAL) and plasma of mice were studied. IRFI 016 and its active metabolite IRFI 005 are both present in BAL and plasma after oral administration of IRFI 016. In BAL no delay times were noted, in comparison with plasma, regarding Cmax time nor significant variation of t1/2 and the elimination constant (Kel). IRFI 016, orally administered, is very rapidly absorbed and, both in unaltered form and as its active metabolite, reaches the anatomic site where it carries out its principal pharmacological activity, according to the same kinetic course observed in plasma.