Qualitative and quantitative determination of drotaverine metabolites in rat bile

After oral and intravenous administration of drotaverin-14C its metabolites were determined in rat bile. Three major metabolites were identified by tlc. All the metabolites appeared in conjugated form. No unchanged drotaverine was detectable in the bile, except after treatment with doses much in excess of the therapeutic range. The ratio of major metabolites to unchanged product was determined by two-dimensional densitometry using a Telechrom Video Densitometer.