Ultra-Performance Liquid Chromatography with Electrospray Ionization Tandem Mass Spectrometry for the Determination of Ketoconazole in Anti-Dandruff Shampoo

A fast and highly sensitive method for the quantification of ketoconazole in antidandruff emulsion formulas was developed and validated. Sample preparation utilizing solid-phase extraction was a simple and reliable method for extracting both ketoconazole and its internal standard miconazole from the samples: 97 ± 3% for ketoconazole and 93 ± 4% for the internal standard. The separation by isocratic ultra-high performance liquid chromatography and multiple-stage mass spectrometry with a reversed-phase C₁₈ column was performed within 10 min. The method, which operated in a selective reaction monitoring mode specific to ketoconazole, was validated for quantitative use. The intra- and inter-day precision values were <5% and their accuracies ranged from 89.6 to 96.2%. The ketoconazole concentrations in two samples obtained by the established protocol were comparable to the concentrations indicated on the labels of the formulations. Thus, this paper describes the first use of ultra-high performance liquid chromatography and multiple-stage mass spectrometry for the determination of ketoconazole.