Simultaneous quantification of alpha-/beta-diastereomers of arteether, sulphadoxine and pyrimethamine: A promising anti-relapse antimalarial therapeutic combination, by liquid chromatography tandem mass spectrometry

摘要

A rapid, sensitive, selective and specific HPLC/ESI-MS/MS assay method was developed and validated for the simultaneous quantitation of alpha/beta-diastereomers of arteether (AE), sulphadoxine (SDX) and pyrimethamine (PYR) in rat blood plasma using propyl ether analogue of P-arteether as internal standard. The method involved a single-step, liquid-liquid extraction with ethyl acetate and the analytes were chromatographed on a C-18 chromatographic column by isocratic elution with methanol: ammonium acetate buffer (10 mM, pH 4) (90:10%, v/v) and analyzed by tandem mass spectrometry. The run time was 4.5 min and the weighted (1/x(2)) calibration curves were linear over a range of 0.78-400 ng ml(-1). The method was validated fully and the lower limit of quantification (LLOQ) in plasma was 0.78 ng ml(-1) for all the analytes. The intra- and inter-day precision and accuracy were found to be well within the acceptable limits (< 15%) and the analytes were stable after three freeze-thaw (f-t) cycles. The absolute recoveries were consistent and reproducible. The assay method was applied to pre-clinical pharmacokinetic interaction studies of alpha-/beta-AE, SDX and PYR in rats. (c) 2006 Elsevier B.V. All rights reserved.