A rapid thin layer chromatographic procedure to identify poor and extensive oxidative drug metabolizers in man using...

A rapid TLC method is presented to distinguish poor oxidative drug metabolizers from extensive oxidative drug metabolizers. Dextromethorphan (1) is used as test probe because it is safe, well characterized, generally available and easy to measure. The method is based on the extraction of 1 and its major oxidative metabolite dextrorphan (2) from urine, followed by separation on a TLC plate and visualized by a combined Marquis/Mandelin reaction. The intensities of the spots are then compared with a series of standard mixtures containing 1 and 2 in a ratio of 0.3 at different concentrations. This value represents the antimode that separates poor from extensive metabolizers, and an individual is identified as a poor metabolizer if the intensity ratio of the two spots from his urine sample is higher than 0.3. The proposed TLC method was cross checked with an HPLC method and found to correctly identify 9 poor metabolizers out of a population of 71 volunteers.