Liquid-chromatographic determination of propisomide and its mono-N-dealkylated metabolite in plasma and urine.
Abstract We describe a "high-performance" liquid-chromatographic assay for simultaneously determining propisomide and its mono-N-dealkylated metabolite in plasma and urine. After extraction with dichloromethane at alkaline pH, the unchanged drug, its metabolite, and the internal standard are separated by liquid chromatography on a reversed-phase column and the absorbance of the eluate is measured at 254 nm. Selectivity, sensitivity, and reproducibility are excellent. Results are similar to those by gas chromatography for propisomide but, in addition, the metabolite can be simultaneously measured in the same clinical sample. We also report results by this method for blood and plasma samples from a volunteer receiving a single 200-mg dose of propisomide.