A rapid, cost-effective liquid chromatographic method for the determination of chloroquine and desethylchloroquine in biological fluids.

We have developed a rapid and cost-effective method for the analysis of chloroquine (CQ) and desethylchloroquine in biological samples. The extraction procedure is a simple two-step process that has eliminated the need for costly extraction and evaporation equipment. The mobile phase consists largely of a buffer that was mostly water, making the method cheap to run. The calibration curves were linear from 0 to 200 ng/ml for plasma and from 0 to 3,000 ng/ml for urine. The regression coefficients were of the order of 0.99 and above in all instances. The interassay coefficient of variation (CV) for the assay of CQ was 4.8% in plasma and 4.4% in urine. The intraassay CV for CQ was 3.8% in plasma and 4.2% in urine. There were no interfering peaks from presently used antimalarial drugs. Baseline resolution and separation were very good. The method was found to be applicable for pharmacokinetic studies.