Liquid chromatography-mass spectrometry in evaluation of bioequivalence of two kinds of amlodipine besylate tablets

Objective:To establish a liquid chromatography-mass spectrometry(LC-MS) method for determining the concentration of amlodipine besylate in human plasma and to evaluate the bioequivalence of 2 kinds of amlodipine besylate tablets.Methods: Twenty healthy male volunteers were enrolled into a single crossover study.A single dose of the suspension equivalent to 10 mg amlodipine besylate or a reference preparation was given in a crossover way.The plasma concentrations of amlodipine besylate were determined by LC-MS method in the volunteers at different time points;the pharmacokinetic parameters and relative bioavailability were calculated and the bioequivalence of the 2 preparations were evaluated.Results: The pharmacokinetic parameters for experimental and the reference preparations were: C_max(6.21±1.88) vs(6.03±1.08) ng/ml;AUC_0-120(250.68±52.61) vs(246.14±52.11) ng h/ml;T_max(6.0±2.3) vs(6.1± 2.5) h;t_1/2(40.45±6.68) vs(43.74±9.05) h,respectively.The linear range of the present method was 0.1-20.0 ng/ml;the lowest detectable concentration of amlodipine besylate was 0.1 ng/ml.There was no significant difference in pharmacokinetic parameters between the 2 tablets.Conclusion: The present method is simple to use,fast,and accurate.The 2 preparations of amlodipine besylate are bioequivalent.