Simultaneous Determination of β-Artemether and its Metabolite Dihydroartemisinin in Human Plasma and Urine by a High-Performance Liquid Chromatography-Mass Spectrometry Assay Using Electrospray Ionisation

摘要

A sensitive and selective method is described for the determination of β-artemether (AM) and its metabolite dihydroartemisinin (DHA) in human plasma and urine using artemisinin (IS) as internal standard. The method consists of a liquid-liquid extraction using 2,2,4-trimethylpentane – ethyl acetate (7:3 v/v) with subsequent evaporation of the supernatant to dryness followed by the analysis of the reconstituted sample by liquid chromatography – mass spectrometry (LC-MS) using positive electrospray ionisation (ESI). The acquisition was performed using a mass range scan and the ions (MH+−CH3OH) m/z 267.2, (MH+−H2O) m/z 267.2 and (MH+) m/z 283.2 for AM, DHA and IS respectively were used for compound quantifications. Chromatography was performed on a C18 reversed-phase column using a gradient of acetonitrile – ammonium acetate 10 mM, glacial acetic acid 0.1% as a mobile phase. The method was validated over a concentration range of 10–1000 ng mL−1 using 1 mL of human plasma per assay and over a concentration range of 5–500 ng mL−1 using 2 mL of human urine per assay. The method was applied to the quantitation of β-artemether and dihydroartemisinin in human plasma and urine of volunteers participating in a drug pharmacokinetic study.