Bioequivalence study of Nimodipine Sustained-Release Tablets in Healthy Volunteers

OBJECTIVE To study the pharmacokinetics and relative bioavailabilty of nimodipine sustained-release tablets and to evaluate the bioequivalence. METHODS A single dose and multiple oral doses of nimodipine sustained-release tablets (the test and the reference) were given to 18 healthy volunteers in a randomized,crossover study. The nimodipine concentration in plasma was determined by High Performance Liquid Chromatography (HPLC). RESULTS The main pharmacokinetic parameters for a single oral dose of 60 mg test and reference preparation were calculated as the follows:t1/2 (2.70±0.48) and (2.85±0.81) h;ρmax (31.00±9.13) and (32.13±10.00) μg·L-1; tmax (2.97±0.88) and (2.89±0.76 ) h. AUC0-t (177.64±42.43) and (186.41±49.37) μg·h·L-1,AUC0-∞ (190.20±45.22) and (204.34±54.46) μg·h·L-1. The relative bioavailability of the test was (99.18±25.08) %. The pharmacokinetic parameters of multiple doses study were as follows:the mean steady state ρss max (42.37±6.34) and (45.66±6.88) μg·L-1; ρss min(13.37±3.37) and (13.51±2.55) μg·L-1;DFss (118.57±21.09) and (127.22±27.54)%. The relative bioavailability of the test wa(s97.11±12.25)%. CONCLUSION No statistical differences were observed between these two preparations,the results showed that the two preparations were bioequivalent.