Pharmacokinetic study and bioequivalence of amlodipine besylate tablet in healthy volunteers

Objective: To establish a LC/MS/MS method for determination of amlodipine besylate in human plasma,and investigate the pharmacokinetics and bioequivalence of amlodipine besylate tablet in Chinese healthy volunteers.Methods: A two-way crossover test was used to sudy the pharmacokinetics of amlodipine besylate.18 male healthy volunteers randomly receive a single crossover oral dose of amlodipine besylate tablets or reference tablets.The concentration of amlodipine besylate in plasma was determined by LC/MS/MS and DAS 2.0 was used to analyze the pharmacokinetic parameters.Results: The linear range of amlodipine besylate in plasma was from 0.050 to 20.0 μg·L-1(r=0.994 9) and the limit of detection was 0.050 μg·L-1.The intra-and inter-day precision was less than 7.4%.The main pharmacokinetic parameters of reference and test tablets of amlodipine besylate were: AUC0~tn(249.4±68.6) and(251.9±53.4)μg·h·L-1;AUC0~∞(287.9±84.0) and(288.2±67.5)μg·h·L-1;Cmax(6.02±1.45) and(6.39±1.71)μg·L-1;Tmax(7.90±2.94)h and(8.00±3.40)h,respectively.According to AUC0~tn,the relative bioavailability for test tablets was(104.7±25.2) %;and according to AUC0~∞,the relative bioavailability for test tablets was(103.5±25.7)%.Conclusion: The assay method is shown to be sensitive and accurate with reliable results.The test tablets are bioequivalent to the reference tablets.