Implementing DBS methodology for the determination of Compound A in monkey blood: GLP method validation and investigation of the impact of blood spreading on performance

Background: This article describes validation work for analysis of an Abbott investigational drug (Compound A) in monkey whole blood with dried blood spots (DBS). The impact of DBS spotting volume on analyte concentration was investigated. Results: The quantitation range was between 30.5 and 10,200 ng/ml. Accuracy and precision of quality controls, linearity of calibration curves, matrix effect, selectivity, dilution, recovery and multiple stabilities were evaluated in the validation, and all demonstrated acceptable results. Incurred sample reanalysis was performed with 57 out of 58 samples having a percentage difference (versus the mean value) less than 20%. A linear relationship between the spotting volume and the spot area was drawn. The influence of spotting volume on concentration was discussed. Conclusion: All validation results met good laboratory practice acceptance requirements. Radial spreading of blood on DBS cards can be a factor in DBS concentrations at smaller spotting volumes.