Identification of benidipine hydrochloride metabolites in rats and dogs.

A study of the metabolism of [14C]-(+/-)-(R*)-2,6-dimethyl-4-(m-nitrophenyl)- 1,4-dihydropyridine-3, 5- dicarboxylic acid (R*)-1-benzyl-3-piperdidinyl ester, methyl ester hydrochloride (14C-benidipine hydrochloride, 14C-KW-3049) revealed as major metabolic pathways oxidative N-dealkylation, hydrolysis of the ester moiety, dehydrogenation of the 1,4-dihydropyridine ring, hydroxylation of the methyl group and decarboxylation in rat and dog. Rat and dog showed similar metabolic pathways, but some quantitative differences were found between rat and dog.