Determination of levamisole in the plasma of patients with falciparum malaria using high-performance liquid chromatography.
The oral antihelmintic drug levamisole reduces sequestration of late stage parasites in falciparum malaria. Levamisole has been also identified as a cocaine adulterant. In the present study, authors developed a sensitive and selective HPLC-assay for the determination of levamisole in the plasma from patients with falciparum malaria. Chromatographic separation was achieved by using a C18 column and with an isocratic elution system comprising phosphate buffer and acetonitrile. The eluate was monitored at 235 nm by diode array detection. The calibration curve for levamisole was linear in the range from 50 to 2000 ng/mL (r2 > 0.999). The limit of quantification was 28 ng/mL and the inter- and intraday coefficients of variation were less than 7%. No interference from commonly prescribed malaria treatments was observed. The HPLC method is simple, rapid, and robust and is suited for monitoring levamisole patients in routine or toxicological studies.