Validation and clinical application of dried blood spot assay for quantitative assessment of edoxaban in healthy adults.

Dried blood spot (DBS) is a sampling approach that offers several advantages over plasma and whole blood (WB) sampling, but several factors, such as hematocrit and temperature, can adversely affect quantitation. In an open-label, three-way crossover study in healthy subjects, we explored the correlation between DBS, WB and plasma samples, and between DBS samples from finger-prick and venipuncture blood for measuring edoxaban and its metabolite M-4 using LC-MS/MS. The methods were validated comprehensively.