Bioequivalence and Pharmacokinetics Study of Two Zidovudine/Lamivudine Tablets in Chinese Healthy Volunteers.

Zidovudine/lamivudine tablets are nucleoside reverse transcriptase inhibitors that are used to treat human immunodeficiency virus. The objective of this study was to investigate the bioequivalence and pharmacokinetics (PKs) of test and reference preparations of zidovudine/lamivudine tablets in healthy Chinese subjects. We designed a randomized, open, single-center, single-dose, 2-crossover experiment with a 7-day washout period involving 20 healthy subjects. The subjects were given a single dose of the test or reference preparation after fasting overnight for 10 hours. Blood samples were subsequently collected at scheduled time points from 0 hour (preadministration) up to 24 hours postadministration. The plasma concentrations of zidovudine and lamivudine were determined by a validated ultra-performance liquid chromatography-tandem mass spectrometry method. Analysis of variance (ANOVA) was used to compare differences in the mean values of key PK parameters between the 2 preparations. Bioequivalence was evaluated by 2 one-sided t-tests and 90% confidence intervals (CIs) of the geometric mean ratio (GMR). In total, 19 of the 20 subjects completed the trial. Based on the analysis of PK parameters, the relative bioavailability of zidovudine and lamivudine was 101.1% ± 2.0% and 100.3% ± 1.5%, respectively. ANOVA found no significant difference in primary PK parameters when compared between the 2 formulations, and the 90% CIs of the GMR of the 2 formulations were within the bioequivalence margins of 80%-125%. No serious adverse events occurred. Thus, we confirmed that the 2 preparations were bioequivalent in healthy Chinese volunteers. Our analysis demonstrated that both products showed good tolerance in all subjects.

Bioequivalence and Pharmacokinetic Evaluation of Two Metformin Hydrochloride Tablets Under Fasting and Fed Conditions in Healthy Chinese Volunteers.

This article aims to assess the bioequivalence of the test and the reference metformin hydrochloride tablets in healthy Chinese volunteers under fasting and fed conditions and to explore the effect of food on the pharmacokinetic (PK) profiles of both formulations. In total, 56 healthy Chinese subjects (28 in each group) were enrolled in this randomized, open, single-center, single-dose, 2-treatment, 2-sequence, 2-cycle cross clinical trial. The subjects were administrated a single dose of the test and the reference tablets at 0.25 g with a 7-day washout. Venous blood samples of all subjects were taken from predose 0 hour to postdose 24 hours according to the planned times. PK parameters for metformin were analyzed and calculated with noncompartmental methods. There were no significant differences in the PK parameters between the 2 formulations under both the fasting and the fed states. The 90% confidence intervals of 2 formulations were within 80.00%-125.00% based on Cmax , AUC0-t , and AUC0-∞ under both conditions. High-fat and high-calorie diets delayed the Tmax and reduced the AUC0-t and AUC0-∞ . No severe adverse events occurred in this study. Two metformin hydrochloride tablets were bioequivalent under both fasting and fed states; the high-fat and high-calorie diet could lower the rate and extent of absorption of metformin in healthy Chinese volunteers.