This study will test the hypothesis that the Final Market Image (FMI) sitagliptin/metformin 50 mg/500 mg and 50 mg/850 mg (Fixed Dose Combination) FDC tablet and co-administration of corresponding doses of sitagliptin and China-sourced metformin as individual tablets will be bioequivalent based on assessment of the AUC(0-t) and Cmax, for both sitagliptin and metformin.