Objective:Compare the bioavailability of the test formulation(T)and reference formulation(R)of metformin hydrochloride sustained-release tablets in healthy adult Chinese subjects under fasting and fed conditions.Methods:Adopting a randomized,open label,single dose,two period,double crossover trial design method.32 and 36 healthy adult subjects were enrolled in the fasting group and fedgroup,respectively.Each group was randomly divided into two cycles,with a single oral dose of 0.5 g of the test formulation(T)or reference formulation(R)per cycle.Collect blood samples according to the prescribed time and use LC-MS/MS method to determine metformin in plasma for bioequivalence analysis.Results:The 90%confidence intervals for the geometric mean ratios of Cmax、AUC0-t and AUC0-∞ of the test formulation to the reference formulation ranged from 80.00%to 125.00%under both fasting and fed conditions.Conclusion:Under fasting and fed conditions,two sustained-release metformin hydrochloride tablets have bioequivalence.