Studies on the Analysis of Drugs by Use of Isotopes. IV. : Reverse Dilution Analysis of the Metabolites of ¹⁴C-Ephedrine.

Abstract

Metabolic rate of ephedrine excretion into urine was examined by intraperitoneal injection of ¹⁴C-labeled d- and l-ephedrine into rats. Metabolic products in the urine was examined by paper chromatography combined with reverse dilution analysis. The l-compound is demethylated or hydroxylated in the p-position in vivo but the d-compound does not undergo these changes. Hippuric acid and a small amount of benzoic acid were detected besides a fair amount of nonidentified carboxylic acid and a neutral product as the metabolites.