Determination of levamisole in the plasma of patients with falciparum malaria using high-performance liquid chromatography.

ABSTRACT

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: The HPLC method is simple, rapid, and robust and is suited for monitoring levamisole patients in routine or toxicological studies.