Pharmacokinetics and bioequivalence of nifedipine sustained-release tablets after multiple doses administration in healthy volunteers / 中国临床药理学与治疗学

ABSTRACT

AIM: To investigate the pharmacokinetic properties and bioequivalence of nifedipine sustained-release tablets after multiple doses administration in healthy volunteers. METHODS: Twenty two male healthy volunteers were enrolled in a randomized two-way crossover design with multiple doses (20 mg·d-1×7 d) study. Nitrendipine was used as the internal standard and the concentrations of nifedipine in plasma were determined by HPLC-APCI-MS. The pharmacokinetic parameters were calculated and the bioequivalence were compared by DAS (ver 1.0) program. RESULTS: The pharmacokinetic parameters of test and reference preparations were as follows Cmax (52.5±27.4) and (54.0±31.2) ng·ml-1;Cmin (5.4±4.1) and (6.2±5.9) ng·ml-1;Cav (16.8±9.2) and (19.3±12.4) ng·ml-1;Tmax (3.7±0.9) and (4.1±1.1) h;t1/2 (8.9±4.9) and (8.5±3.1) h;AUC0-τ (403.4±221.0) and (461.9±296.6) μg·h·L-1, AUC0-36h (444.4±256.1) and (503.1±330.9) ng·h·ml-1;AUC0-∞ (482.1±268.9) and (542.3±348.4) ng·h·ml-1;DF (299.8±117.7)% and (279.2±97.5)%, respectively. There were no significant differences (P>0.05) in Tmax, Cmax, Cmin, Cav, DF, AUC0-τ, AUC0-36h, AUC0-∞ and t1/2 between the two preparations. The relative bioavailability of test tablets was (100.6±38.6)%. CONCLUSION:The test and reference preparations were bioequivalence.