Application of the DBS methodology to a toxicokinetic study in rats and transferability of analysis between bioanalytical laboratories.

Background: There are little published data on either the comparison of liquid blood and dried blood spots (DBS) analyses or the ability to generate comparable DBS data at different analytical laboratories. We assess the comparative results of samples stored as liquid blood and DBS. We also determine the transferability of DBS samples by comparing the analysis at two laboratories.

Results: Bioanalytical methods for the analysis of pioglitazone in DBS and liquid blood samples were validated to US FDA guidelines. Pharmacokinetic data generated from DBS and liquid blood samples demonstrated area under the time-concentration profile (0-24 h) values within 3% of each other and maximum plasma concentration values within 7% of each other. Comparing DBS sample results at different laboratories showed more than 99% of results agreeing within 20%.

Conclusions: The results indicate that comparable concentration results are obtained from DBS and whole blood samples within the same laboratory, indicating that changing between the two matrices is viable. The comparable results of DBS samples analyzed at two laboratories using different analytical methodologies demonstrate that the technique is robust and transferable.