GSKA is a compound that was in development in clinical trials. A bioanalysis method to quantify GSKA using volumetric absorptive microsampling (VAMS) was developed and hematocrit (HCT) related assay bias was investigated.
After accurate sampling of 10 μl blood, VAMS tips were air dried approximately 18 h and desorbed by an aqueous solution containing internal standard. The recovered blood underwent liquid-liquid extraction in ethyl acetate to minimize matrix suppression. Assay accuracy, precision, linearity, carryover, selectivity, recovery, matrix effects, HCT effects and long-term quality control stability were evaluated.
HCT-related assay bias was minimized in 30-60% blood HCT range, and all validation parameters met acceptance criteria. The method is suitable for quantitative analysis of GSKA in human blood.