Pharmacokinetics of Nifedipine-Sustained Release Tablets in Healthy Subjects After a Single Oral Administration: Bioequivalence Analysis and Food Effects.

Abstract

We compared newly developed delayed-release oral tablets (test) of 30-mg nifedipine (NFP) with its marketed counterpart (30mg; reference) in healthy adult Chinese volunteers to assess the former's bioequivalence. This was a randomized, open-label, four-period, crossover trial study including fasting and fed trials. The participantswere randomly administered test or reference formulations (1:1 ratio) throughout each period, with a 7-day washout period. In the next session, they were administered the alternate products. Liquid chromatography-tandem mass spectrometry and WinNonlin software were used to evaluate the bioequivalence of the maximum plasma concentration (Cmax ) of NFP and the area under the concentration-time curve (AUC). In total, 46 and 48 people participated in the fasting and postprandial trials. In both groups, the 90% confidence intervals of geometric mean ratios of Cmax , AUC from time zero to time t, and AUC from time zero to infinity were in the equivalence range (80%-125%). When NFP was administered concomitantly with a high-fat meal, time to maximum concentration was approximately twofold earlier, absorption was approximately 4.8% less, and Cmax exhibited a slight change relative to those under fasting conditions. Moreover, no serious adverse events were recorded in the participants. The present findings confirm the bioequivalence of test and reference formulations of NFP tablets under fasting and postprandial conditions.