Bioequivalence of amoxicillin capsules in healthy Chinese subjects

Objective: To study the bioequivalence of amoxicillin capsules in healthy Chinese subjects.Methods: A single-center, open-label, randomized, two-formulation, two-period, two-sequence crossover trial was designed.A total of 48 subjects(24 in each fasting and postprandial trial)were orally administered 0.25 g of amoxicillin capsule test formulation or reference formulation.High performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to determine the plasma concentration of amoxicillin at different times after administration, and the main pharmacokinetic parameters were calculated to determine whether the two formulations were equivalent.Results: The fasting trial showed the maximum plasma concentration (C_max)of the test formulation and the reference formulation of amoxicillin were (5, 483.296±1, 321.102) ng/mL and(5, 611.291±1, 659.407) ng/mL, respectively; the area under the concentration-time curve from time 0 to time t(AUC_0-t)were(13, 255.3±1, 715.7)h·ng/mL and(13, 115.5±2, 091.7)h·ng/mL, respectively; the AUC from time 0 to infinity (AUC_0-∞) were (13, 329.4±1, 718.8) h·ng/mL and (13, 192.7±2, 107.1) h·ng/mL, respectively; both of their T_max was 1.38 h.The postprandial trial showed the C_max of the test formulation and the reference formulation of amoxicillin were C_max were (4, 218.072±780.598) ng/mL and (4, 156.713±877.752) ng/mL, respectively; AUC_0-t were (13, 073.9±1, 584.3) h·ng/mL and (12, 817.8±1, 575.5) h·ng/mL, respectively; AUC_0-∞were (13, 166.8±1, 606.0) h·ng/mL and (12914.8±1587.2) h·ng/mL, respectively; both of their T_max was 3.00 h.The 90% confidence intervals (CI) of the geometric mean ratios of C_max, AUC_0-t and AUC_0-∞of the two preparations were all within the acceptable bioequivalence range (80%-125%).Conclusion: The absorption rate and degree of two amoxicillin capsules are bioequivalent in Chinese healthy subjects.