SIMULTANEOUS DETERMINATION OF CHLOROQUINE AND SELECTED CALCIUM(II) CHANNEL BLOCKERS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Chloroquine (CQ), which is the primary drug for treatment and prophylaxis against malaria, has become ineffective because of the high prevalence of CQ-resistant P. falciparum parasites, but resistant parasites exposed to a Ca(II) channel blocker become as susceptible to CQ as sensitive parasites. A reversed-phase liquid chromatographic method is described for simultaneously determining CQ, its metabolites desethyl-CQ and bisdesethyl-CQ, the Ca(II) channel blocker verapamil, and the tiapamil analogue N-(3,4-dimethoxyphenethyl)- N-methyl-2-(naphthyl)-m-dithiane-2-propylamine hydrochloride. The analytes were separated by gradient elution with acetonitrile and 1-heptane sulfonic acid; the detector wavelength was 232 nm. The mean recovery from spiked plasma was 100.1 ± 2.28 (SD). Within-day retention times were reproducible to within ± 0.03 SD of mean values and the lower limit of detection was about 2 ng of each analyte. © 1990.