Pharmacokinetics and Bioequivalence of a Generic Fixed-Dose Combination Tablet of Metformin Hydrochloride/Vildagliptin Versus a Branded Product in Healthy Chinese Subjects Under Fed and Fasting Conditions

The purpose of this study was to compare the bioequivalence and safety of test and reference preparations of fixed-dose combination tablets of metformin hydrochloride/vildagliptin 850 mg/50 mg in healthy volunteers under fasting and fed conditions for marketing authorization in China. A single-dose, randomized, open-label, 2-way crossover study was conducted. Blood samples were collected up to 36 hours after dosing in each period with a 7-day washout. Pharmacokinetic parameters, including maximum plasma concentration (C-max), time to reach C-max, area under the plasma concentration-time curve (AUC) from time 0 to the last time point of the measurable concentration, AUC from time 0 to infinity, terminal elimination half-life, and apparent clearance, were calculated using noncompartmental methods and compared between the 2 formulations. Safety profiles were assessed, including significant findings of vital signs, electrocardiogram, laboratory tests, physical examination, and adverse events. A total of 30 healthy subjects (19 men, 11 women) were randomized, and 29 subjects were treated under fasting conditions. Likewise, 30 subjects (24 men, 6 women) were randomized and treated under fed conditions. The geometric mean ratio and corresponding 90% confidence intervals of C-max, AUC from time 0 to the last time point of the measurable concentration , and AUC from time 0 to infinity for both metformin hydrochloride and vildagliptin between the 2 fixed-dose combination formulations were within the bioequivalence acceptance range of 80% to 125% under fasting or fed conditions. Therefore, the generic and branded formulations were bioequivalent and well tolerated in healthy Chinese subjects.