IDENTIFICATION OF URINARY METABOLITES OF ECABAPIDE IN RAT

1. C-14-Ecabapide, yl]carbamoyl]methyl]amino-N-methyl[C-14]benzamide, was dosed orally to rat (100mg/kg). Within 48h after dosing, 36.7+/-5. 4 and 55.7+/-11.8% of the administered radioactivity was recovered fro m urine and faeces respectively. 2. The unchanged drug was the major c ompound excreted in the urine and accounted for 37% of the urinary rad ioactivity. Seven urinary metabolites were purified by preparative hpl c and their structures were elucidated by mass and H-1-nmr spectrometr y. 3. The major metabolic pathway of ecabapide was found to be the for mation of 3-amino-N-methylbenzamide produced by N-dealkylation of the secondary amine at the 3-position of the benzamide moiety followed by acetylation. 4. Further metabolic pathways of the N-methylbenzamide mo iety were N-demethylation via the carbinolamine derivatives, and/or ar omatic hydroxylation followed by glucuronidation.