Background: Vildagliptin, a potent dipeptidyl peptidase IV inhibitor (DPP-4i), is usually administered twice daily to provide ≥90% inhibition of DPP-4 over 24 hours. Considering most type 2 diabetes (T2D) patients are on multiple medications, reducing dosing and pill burden can increase patient convenience. A 100 mg Vildagliptin sustained release (SR) formulation that would inhibit DPP-4 ≥ 80% over 24 hours with a lower dosing frequency was developed. The study was thus conducted to evaluate the pharmacodynamics, pharmacokinetics, and safety profile of once-daily Vildagliptin SR compared to twice-daily Vildagliptin immediate-release (IR) formulation. Results: Twenty-four healthy adult male subjects were enrolled, and 22 completed the clinical phase of the study. The DPP-4 inhibition over time was comparable between the formulations. At 24 hrs single dose of once-daily Vildagliptin SR 100 mg tablet inhibited DPP4 by 89.58%, whereas twice-daily Vildagliptin IR 50 mg by 91.052%. The pharmacokinetic parameters like peak plasma concentration (Cmax), area under the plasma concentration-time curve from 0 hours to the last measurable concentration (AUC0-t) and AUC-time curve up to infinity (AUC0-inf) were not significantly different in both groups. Besides this, both groups reported no serious adverse effects during the study period. Conclusion: The above result shows that once-daily Vildagliptin SR 100 mg is bioequivalent to twice-daily Vildagliptin IR 50 mg. Moreover, the ability of Vildagliptin SR 100 mg to provide above 80% DPP-4 inhibition coverage over 24 hrs may help to achieve a clinically meaningful glucose-lowering effect and reduce the pill burden in diabetes patients. Keywords: Vildagliptin, dipeptidyl peptidase IV inhibitor (DPP-4i), type 2 diabetes (T2D) patients, pharmacokinetic parameters