Abstract
1. The disposition of adiphenine labelled with 14C in two positions has been investigated in rats and mice after i.v. administration, and has been compared with that of the [14C]diethylethanolamine HCI and of the [14C]diphenylacetic acid.
2. Radioactivity in the blood declined in a biphasic manner. Biliary elimination depended upon the 14C-labelled compound administered: <5% dose for the diethyletha-nolamine moiety, 100% dose for the carboxylic moiety. Of the radioactivity appearing in rat bile, <1% is associated with unchanged adiphenine.
3. In preliminary metabolic studies, three major metabolites have been identified: diphenylacetic acid, diethylethanolamine and a diphenylacetic acid glucuronide.
4. Uptake by the brain of [14C]adiphenine shortly after dosing is 15 times greater than that of blood. Radioactivity is also found in the hypophysis, the adrenals and melanoid pigments, with a concn. up to 30 times greater than that found in the blood.