Lindegardh N, Hanpithakpong W, Kamanikom B, Singhasivanon P, Socheat D, Yi P, Dondorp A M, McGready R, Nosten F, White N J, Day N P J
Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
J Chromatogr B Analyt Technol Biomed Life Sci. 2008 Dec 1;876(1):54-60. doi: 10.1016/j.jchromb.2008.10.021. Epub 2008 Oct 18.
A bioanalytical method for the analysis of artesunate (ARS) and its metabolite dihydroartemisinin (DHA) in human plasma using protein precipitation and liquid chromatography coupled to positive tandem mass spectroscopy was developed. The method was validated according to published US FDA-guidelines and showed excellent performance. However, when it was applied to clinical pharmacokinetic studies in malaria, variable degradation of the artemisinins introduced an unacceptable large source of error, rendering the assay useless. Haemolytic products related to sample collection and malaria infection degraded the compounds. Addition of organic solvents during sample processing and even low volume addition of the internal standard in an organic solvent caused degradation. A solid phase extraction method avoiding organic solvents eliminated problems arising from haemolysis induced degradation. Plasma esterases mediated only approximately 20% of ex vivo hydrolysis of ARS into DHA. There are multiple sources of major preventable error in measuring ARS and DHA in plasma samples from clinical trials. These various pitfalls have undoubtedly contributed to the large inter-subject variation in plasma concentration profiles and derived pharmacokinetic parameters for these important antimalarial drugs.
建立了一种生物分析方法，用于通过蛋白质沉淀和液相色谱-正离子串联质谱联用技术分析人血浆中的青蒿琥酯（ARS）及其代谢物二氢青蒿素（DHA）。该方法根据美国食品药品监督管理局（US FDA）发布的指南进行了验证，表现出优异的性能。然而，当将其应用于疟疾的临床药代动力学研究时，青蒿素的可变降解引入了不可接受的大量误差来源，导致该检测方法无用。与样本采集和疟疾感染相关的溶血产物会降解这些化合物。在样本处理过程中添加有机溶剂，甚至在有机溶剂中少量添加内标都会导致降解。一种避免使用有机溶剂的固相萃取方法消除了溶血诱导降解引起的问题。血浆酯酶仅介导约20%的ARS离体水解为DHA。在测量临床试验血浆样本中的ARS和DHA时，存在多个主要可预防误差来源。这些各种陷阱无疑导致了这些重要抗疟药物血浆浓度曲线和推导的药代动力学参数在受试者之间存在较大差异。
