A simple LC-MS/MS method to determine plasma and cerebrospinal fluid levels of albendazole metabolites (albendazole sulfoxide and albendazole sulfone) in patients with neurocysticercosis

ABSTRACT The development and validation of an LC‐MS/MS method for the simultaneous determination of albendazole metabolites (albendazole sulfoxide and albendazole sulfone) in human plasma are described. Samples of 200 μL were extracted with ether–dichloromethane–chloroform (60:30:10, v/v/v). The chromatographic separation was performed using a C18 column with methanol–formic acid 20 mmol/L (70:30) as the mobile phase. The method was linear in a range of 20–5000 ng/mL for albendazole sulfoxide and 10–1500 ng/mL for albendazole sulfone. For both analytes the method was precise (RSD