l-Bunolol metabolism in rats: identification of urinary metabolites.

Urine collected for 24 hr from rats given a single oral dose of 3H-l-bunolol (10 mg/kg) was found to contain only 25.8% of the dose and more than 30 labeled compounds. Nine compounds were identified and quantified as follows: bunolol (0.35% of urinary tritium), bunolol glucuronide (5.12%), bunolol sulfate (0.08%), dihydrobunolol (0.08%), dihydrobunolol glucuronide (0.74%), dihydrobunolol sulfate (0.12%), hydroxydihydrobunolol (0.58%), beta-(5-oxytetralonyl)lactic acid (0.74%), and (5-oxytetralonyl) acetic acid glucuronide (1.12%). The total quantity of identified labeled compounds was only 2.3% of the dose and 8.9% of the urinary radioactivity.