The determination of the antimalarial blood concentrations employing by fast simple and sensitive methods represents important tool for the optimization of therapeutic regimens currently used in Brazil. In this sense, this paper describes the validation of an analytical methodology by high performance liquid chromatography with ultraviolet detection for the determination of chloroquine in blood samples adsorbed on filter paper, from patients with vivax malaria. It was evaluated: precision intra and inter assay, recovery, limits of detection and quantification, robustness, stability, linearity and selectivity. The results showed that the coefficients of variation of intra assay, at concentrations of 100 to 1000 ng/ml ranged from 6 to 10% for both chloroquine and desethylchloroquine. The coefficient of variation inter assay, at concentrations of 100 to 1000 ng/ml ranged from 5 to 10% and 4 to 10% for chloroquine and desethylchloroq uine, respectively. The limits of detection were 62.5 ng/mL for chloroquine and 50.0 ng/mL f or desethylchloroquine and limits of quantificatio n were 100 ng/mL for both analytes. The recovery in the concentration from 100 to 1000 ng/ml ranged from 90 to 105 % and 95% to 105 for chloroquine and desethylchloroquine, respectively. The method was linear in the range of concentration of 100 to 2000 ng/ml for chl oroquine and 100 to 800 ng/ml for desethylchloroquine. The method showed to be robust for small changes in flow, pH of the mobile phase and composition of the organic phase. It was not observed interferents in the validated procedure among those drugs used to treat malaria. The determination of chloroquine and desethylchloroquine in patients with vivax malar ia whose average values were 1266±455 ng/mL and 357±165 ng/mL, characterized the applicabilityof the validated procedure for the determination of antimalarial drugs in these patients.
|
