Validação de metodologia analítica por cromatografia liquida de alta eficiencia (CLAE), para determinação de mefloquina e carboximefloquina em amostras de sangue total adsorvidas em papel de filtro, em pacientes com malária por Plasmodium falciparum

Abstract

Among the main challenges for malaria control in Brazil and in the world, the advent of resistance to the Plasmodium, particularly Plasmodium falciparum, is presented as the most relevant. Mefloquine is a drug of first line for the treatment of falciparum malaria, and the availability of sensitive methods and low cost for monitoring of blood concentrations of the drug and carboxymefloquine assists in the optimization of drug regimens. In this sense, analytical methodology was validated in accordance with the parameters suggested by official regulatory agency for determination of mefloquine and its carboxylated derivative on the whole blood sample adsorbed on filter paper. The method was employed using High Performance Liquid Chromatography after liquid-liquid extraction of the analytes. The detection was performed at 222nm. No interference was observed in other antimalarials commonly used. The method was linear in concentration range from 0.25 to 2.5 μg/mL for mefloquine and its carboxylated derivative. The detection and quantification limits were 35 ng/mL and 70 ng/mL for mefloquine and carboxymefloquine, respectively. The average intra assay precision was 31±4% for mefloquine and 21±5% for carboxymefloquine. The average inter assay precision was 38±4% for mefloquine and 25±7% for carboxymefloquine. The average of recovery for concentrations of mefloquine ranging from 0.25 to 2.5μg/mL was 83±14% and carboxymefloquine varying from 0.375 to 3740 μg/mL was 88±11%. The drug was stable in samples adsorbed on filter paper for a period of a month. . The method showed to be robust for small changes on pH of the mobile phase. To evaluate the applicability of the method was performed determination of analytes in blood samples adsorbed on filter paper from patients with falciparum malaria. The average concentration of mefloquine was 0.861±0.723 μg/mL and carboxymefloquine 0.472±0.086 μg/mL. The validation parameters of the analytical methodology followed the recommendations proposed by the official agencies and the method showed to be appropriate for determination of mefloquine and carboxymefloquine in whole blood samples adsorbed on filter paper.