Studies on the Metabolic Fate of o-Hexyloxybenzamide

Abstract

Absorption, distribution, and excretion of o-hexyloxybenzamide (HBA) were studied in rats by using <14>^C-labeled compound, which was prepared from <14>^C-salicylic acid. The radioactivity in blood reached maximum level at 2 hr after intraperitoneal administration of the compound dissolved in soybean oil. The level of radioactivity in blood was as low as that in tissues. The rats excreted about 77% of the injected radioactivity in urine, and about 15% in feces within 72 hr. In the case of percutaneous administration of HBA in ointment, about 16% of the administered radioactivity was excreted in urine within 72 hr and about 73% of the administered radioactivity remained at the site of application. In both routes of administration, distribution of radioactivity in rat tissue was more highly located in the kidney and liver than in other tissues. Examination of metabolite in urine showed that no unaltered compound could be detected and main metabolites might be glucuronides of carboxylic acid-type and alcoholic type derivatives derived from the hexyloxy residue of HBA.