Isolation and identification of beta-hydroxyethylaprophen: a urinary metabolite of aprophen in rats.

The metabolism of the anticholinergic drug aprophen was studied in rats after oral administration via stomach intubation. beta-Hydroxyethylaprophen, a major urinary metabolite of aprophen, was isolated and identified by normal-phase high-performance liquid chromatography and electron ionization mass spectrometry. More than 22% of the parent drug was recovered and quantified over a 72-h collection period. Results show that 2,2-diphenylpropionic acid, another major metabolite of aprophen which lacks anticholinergic properties, was also isolated and identified in this study. Experiments are currently underway to synthesize and test the anticholinergic properties of beta-hydroxyethylaprophen in mammals.