MATERIALS AND METHODS: In this trial, a total of 56 eligible subjects were randomly assigned to the fasting group and the postprandial group. The two groups were given 250 mg of the test and reference preparation, respectively. Liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was applied to determine the plasma concentration of cefalexin. PhoenixWinNonlin software (V7.0) was used to calculate the pharmacokinetic parameters of cefalexin using the non-compartmental model (NCA), and the bioequivalence and safety results were calculated by SAS (V9.4) software.
RESULTS: The main pharmacokinetic parameters of the test and reference preparations were as follows, the fasting group: Cmax 12.59 ± 2.65 μg/mL, 12.72 ± 2.28 μg/mL; AUC0-8h 20.43 ± 3.47 h×μg/mL, 20.66 ± 3.38 h×μg/mL; AUC0-∞ 20.77 ± 3.53 h×μg/mL, 21.02 ± 3.45 h×μg/mL; the postprandial group: Cmax 5.25 ± 0.94 μg/mL, 5.23 ± 0.80 μg/mL; AUC0-10h 16.92 ± 2.03 h×μg/mL, 17.09 ± 2.31 h×μg/mL; AUC0-∞ 17.33 ± 2.09 h×μg/mL, 17.67 ± 2.45 h×μg/mL.
CONCLUSION: The 90% confidence intervals of geometric mean ratios of test preparation and reference preparation were calculated, and the 90% confidence intervals of geometric mean ratios of Cmax, AUC0-10h, and AUC0-∞ were within the 80.00% ~ 125.00% range in both groups. Both Cmax and AUC met the pre-determined criteria for assuming bioequivalence. The test and reference products were bioequivalent after administration under fasting as well as under fed conditions in healthy Chinese subjects. This study may suggest that successful generic versions of cefalexin not only guarantee the market supply of such drugs but can also improve the safety and effectiveness and quality controllability of cefalexin through a new process and a new drug composition ratio.