Treatments Against Hair Loss May Hinder Cocaine and Metabolites Detection

The study found that Minoxidil, a common treatment for hair loss, interfered with the detection of cocaine and its metabolites in hair samples. This interference was due to the presence of TMS derivatives of Minoxidil, which produced peaks in chromatograms that overlapped with those of cocaine. Experiments showed that applying Minoxidil to hair could hinder the detection of cocaine and benzoylecgonine, a cocaine metabolite. Attempts to separate these interfering peaks through various methods were unsuccessful. However, a partial solution involved drying the derivatised extract and reconstituting it in methanol, which allowed for the detection of cocaine but not its metabolites. The interference was specific to procedures involving trimethylsilylation, a common derivatisation method in drug analysis.