Determination of Finasteride and Its Metabolite in Urine by Dispersive Liquid-Liquid Microextraction Combined with Field-Enhanced Sample Stacking and Sweeping

The study developed a method for determining the concentrations of finasteride and its metabolite M3 in urine samples using dispersive liquid-liquid microextraction combined with field-enhanced sample stacking and sweeping. The method was validated and found to have an ideal precision and accuracy. The sensitivity enrichments of finasteride and M3 were 362-fold and 480-fold, respectively, compared to the conventional MEKC method. The LOD of the analytes was 20 ng mL-¹. The method was used to detect M3 in urine samples from a patient undergoing finasteride treatment for androgenetic alopecia, and the application can help evaluate the pharmacokinetics of finasteride.