DETERMINATION OF THE ANTIMALARIAL ARTEETHER AND ITS DEETHYLATED METABOLITE DIHYDROARTEMISININ IN PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH REDUCTIVE ELECTROCHEMICAL DETECTION

A rapid, sensitive, and specific reversed-phase HPLC method using reductive electrochemical detection has been developed for the determination of arteether and its omicron-dealkylated metabolite dihydroartemisinin (DQHS) in plasma. The internal standard assay was validated between 25 and 1000 ng/mL, with a coefficient of variation of < 10% for both intra- and interday accuracy and precision. An assay for determination of arteether only, using the n-propyl ether of DQHS as internal standard, was also developed and validated from 5-500 ng/mL. A new automated sample deoxygenation and injection system is used to greatly increase sample throughput. These methods have been used to study the pharmacokinetics of arteether after intravenous and intramuscular administration.