Background: Inhibition of the enzyme dipeptidyl peptidase 4 (DPP-4) is a pharmaceutical treatment for type 2 diabetes. To demonstrate bioequivalence of enzyme inhibition of a new dosage form of the inhibitor vildagliptin, a method for enzyme activity was developed, validated and applied using liquid chromatography and tandem mass spectrometry (LC-MS/MS). Results: The method was validated fit for purpose, including accuracy, precision as well as the stability of the activity and the inhibition of DPP-4 in human plasma. Conclusion: A method for the determination of the activity and inhibition of DPP-4 was developed using LC-MS/MS readout; the characteristics and performance of the method met predefined acceptance criteria and were fit for the purpose of a bioequivalence clinical trial.
Keywords: DPP-4; LC-MS/MS; accuracy; bioequivalence; enzyme inhibition; validation; vildagliptin.