A HPLC METHOD TO DETERMINE CHLOROQUINE IN PLASMA

A simple, rapid and sensitive ion-pair high-performance liquid chromat ographic method is described, which allows the quantification of chlor oquine in human plasma. -(4-ethylpropylamino-1-methyl-butylamino)quino line was synthesized and used as internal standard. After extraction b y toluene from 1 ml plasma, chloroquine was reextracted with 15% phosp horic acid from the organic phase. Chromatographic separation on a RP- 18 column and UV-detection (343 nm) allows sensitive determination of chloroquine in plasma with a lower limit of quantification of 2.5 ng/m l. The method was successfully applied to human plasma samples from 16 subjects after oral administration of 250 mg chloroquine diphosphate.