Abstract
1. The urinary metabolites of pinacidil administered orally to rats, were analysed by h.p.l.c. Seven metabolites were isolated from rat urine following fractionation on an HP-20 column and purified by t.l.c.
2. The major metabolite was pinacidil-pyridine-N-oxide (M-1). ω-Hydroxypinacidil (M-2) and dealkylpinacidil (M-3) were less abundant metabolites, and minor metabolites were the M-2-aldehyde, in which an intramolecular ring had formed (M-4), M-2-pyridine-N-oxide (M-5), carbamoyl-pinacidil (M-7) and M-7-pyridine-N-oxide (M-6).
3. Metabolic pathways of pinacidil in rats were postulated from the isolated metabolites.