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

The document reports on a study that developed a validated method for quantifying ketoconazole in anti-dandruff shampoo and cream formulations using ultra-performance liquid chromatography with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS^n). The method featured a solid-phase extraction for sample preparation, with ketoconazole recoveries of 97±3% and internal standard recoveries of 93±4%. The UPLC separation was completed within 10 minutes, and the method showed high precision (values below 5%) and accuracy (ranging from 89.6% to 96.2%). The limit of quantification (LOQ) for ketoconazole was 0.21 ng/mL, and the substance was stable for 3 months at -20°C. When applied to shampoo and cream samples, the ketoconazole content was consistent with labeled amounts (96% to 104%), and the method was also successfully adapted for use in human plasma, with an LOQ of 0.4 ng/mL and recoveries of 92% to 95%. This study was the first to use the UPLC-ESI-ion trap MS^n technique for the quantification of ketoconazole in these matrices, indicating its potential for drug monitoring.