Distribution and excretion of orally administered oleic acid anilide in the rat

Oleic acid anilide [aniline-14C(U)] was administered by gastric tube to male rats in a single dose (10 mg/kg body weight). After intervals of 3, 6, 24 or 120 h the excretion of radioactivity and the distribution in different organs were studied. The radioactivity was eliminated rapidly through the urine and faeces containing 62% and 38%, respectively, after 24 h. At this time the excretion was almost complete. No radioactivity could be found in the expired air. The absorbed oleic anilide was easily deacylated as evidenced by the excretion of N-acetyl-p-aminophenol conjugate as the main urinary metabolite representing 60-70% of the urinary radioactivity. The radioactivity in faeces was due to the unchanged substance. Twenty-four hours after administration only 0.7% of the dose remained in the total organism with the highest concentrations in the red blood cells, spleen and forestomach. Even after 5 daily doses, an accumulation of radioactivity could not be found.