Pharmacokinetics and Bioequivalence of Nifedipine Sustained-release Capsules in Healthy Volunteers

A randomized cross-over design was conducted to evaluate the pharmacokinetics and bioequivalence of two brands of nifedipine sustained-release capsules in 19 healthy male volunteers.After a single and multiple oral dose of test and reference preparations,the drug concentration in plasma was determined by LC-MS/MS.The main pharmacokinetic parameters of test and reference preparations after a single dose were:t_(max)(2.00±0.82) and(2.08±0.61) h,c_(max)(52.6±17.6) and(49.1±14.0)ng/ml,AUC_(0-t),(300±102) and(298±80.3)ng·h·ml~(-1),respectively.The relative bioavailability was(99.5±16.7)%.The main pharmacokinetic parameters of test and reference preparations after multiple doses were:t_(max)(2.11±0.66) and(2.03±0.49)h,c_(max)(49.8±17.3) and(49.3±18.9)ng/ml,AUC_(SS)(277±142) and(278±120) ng·h·ml~(-1),respectively.The relative bioavailability was(99.5±15.8)%.