Determination of Chloroquine and its Desethyl Metabolite in Whole Blood

Authors:
  • BLBjörn Lindström
    Björn Lindström
  • ÖEÖrjan Ericsson
    Örjan Ericsson
  • GAGunnar Alván
    Gunnar Alván
  • LRLars Rombo
    Lars Rombo
  • LELena Ekman
    Lena Ekman
  • MRMargareta Rais
    Margareta Rais
  • FSFolke Sjoqvist
    Folke Sjoqvist
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Abstract
A high performance liquid chromatography method for analysis of chloroquine and desethylchloroquine was adapted for 75 microliters aliquots of whole blood obtained by finger-prick and dried on filter paper. The precision of the method was satisfactory at whole blood concentrations of 40 nmol/L (coefficient of variation, 5%). The dried samples were stable for at least 7 weeks at 20 degrees C. The concentrations in venous whole blood and in dried samples correlated well. The correlation coefficient was 0.99 for chloroquine and 0.97 for desethylchloroquine. Chloroquine concentrations were marginally but significantly higher in venous whole blood. When fitted to a linear equation (y = bx + a) the relationship was y = 0.96x + 0.03. Desethylchloroquine concentrations did not differ significantly in venous whole blood and in finger-prick blood dried on filter paper. The method is specific and sensitive enough for pharmacokinetic studies and can be used in areas with limited technical facilities.