Use of DBS sample collection to determine circulating drug concentrations in clinical trials : practicalities and considerations.

A clinical investigation was performed into the practicalities of the collection of blood samples for the determination of drug exposures on filter paper, known as dried blood spot (DBS) sampling using a two-period, single-dose, open-label trial conducted in 11 healthy volunteers who received a single oral dose of paracetamol. Questionnaires relating to the blood sampling and spotting process and tolerability were completed by staff and volunteers. Paracetamol concentrations in DBS samples obtained by venous cannula (DBS-Can) were compared against those from fingerprick (DBS-FP) and fresh whole blood obtained from a cannula (WB-Can).