In the past years, Esomeprazole (EMP) was analyzed in human plasma samples, which still has stability issues; thus, the new biosampling technique known as Dried Blood Spot (DBS) might solve the issue. This research aims to evaluate the incurred sample stability of esomeprazole in dried blood spot using high performance liquid chromatographyphotodiode array with lansoprazole as an internal standard. The analytical separation was performed on a C-18 column (Waters, Sunfire™ 5 μm; 250 × 4.6 mm) at 40 °C. The mobile phase used was acetonitrile–phosphate buffer pH 7.6 (40:60% v/v) with a flow rate of 1.00 mL/min; and was detected at 300 nm. The analyte was extracted from dried blood spot by methanol. Incurred sample stability was evaluated from 6 healthy subjects on day 0, 7, 14, and 28, respectively. This method was linear in the range concentration of 70– 1400 ng/mL with r > 0.98. Pharmacokinetic study shows that the average of AUC0–t of EMP in the DBS sample was 1765.41 ngh/mL. The highest percent difference value of esomeprazole’s incurred samples stability on day 7, 14, and 28 from 6 healthy subjects were 9.81%. This result fulfilled the acceptance criteria, which is the percent difference should not be greater than 20%, and 67% of total samples have to fulfill the criteria. The incurred sample stability result showed that esomeprazole was stable in the DBS sample at least until 28 days with the highest value of percent difference is 9.81%.
- Dried blood spot
- Incurred sample