High-performance liquid chromatographic-tandem mass spectrometric method for the determination of clemastine in human plasma

A highly sensitive high-performance liquid chromatographic-tandem mass spectrometric method (HPLC–MS–MS) has been developed to quantitate clemastine in human plasma for the purpose of pharmacokinetic studies. Sample preparation was carried out by liquid–liquid extraction using deuterated clemastine as an internal standard. Chromatographic separation used a C18 reversed phase polymer column giving an extremely fast total run time of 2 min. The method was validated and used for the bioequivalence study of clemastine tablets in healthy male volunteers (n = 28). The lower limit of detection proved to be 0.01 ng/ml for clemastine.