目的:研究在空腹和餐后条件下国产左乙拉西坦片的生物等效性,并探讨餐后给药试验的意义和样本量对试验结果的影响。方法:分别进行空腹和餐后单次给药的二交叉生物等效性试验,22名健康男性受试者口服国产左乙拉西坦片(受试制剂)或进口左乙拉西坦片(参比制剂)0.5 g,液相色谱-串联质谱联用法测定血浆中左乙拉西坦的浓度。采用Win Nonlin 6.4软件,非房室模型法计算药动学参数,药动学参数AUC和Cmax对数转换后,以90%置信区间(90%CI)法进行生物等效性评价。结果:在空腹和餐后条件下,健康男性受试者口服国产和进口左乙拉西坦片后左拉西坦的AUC0~t,AUC0~∞和Cmax几何均数比值(GMR)的90%CI均在80.00%~125.00%的范围内。与空腹给药相比,餐后给药后Tmax延长,Cmax降低,而AUC和t1/2没有差异。结论:在空腹和餐后条件下国产和进口左乙拉西坦片具有生物等效性;左乙拉西坦片的生物等效性试验可仅进行空腹试验,且12例样本量即可。 OBJECTIVE: To study the bioequivalence of domestic levetiracetam tablets under fasting and postprandial conditions and to explore the significance of the postprandial administration test and the effect of sample size on the test results. Methods: Two cross-bioequivalence tests were conducted on fasting and postprandial single administration respectively. Twenty-two healthy male subjects received either domestic levetiracetam tablets (test preparations) or levofloxacin tablets Reference preparation) 0.5 g, liquid chromatography - tandem mass spectrometry determination of plasma concentration of levetiracetam. Pharmacokinetic parameters were calculated using Win Nonlin 6.4 software and non-compartmental model method. After logarithmic conversion of pharmacokinetic parameters (AUC and Cmax), bioequivalence was evaluated by 90% confidence interval (90% CI). RESULTS: Under fasting and postprandial conditions, the geometric mean ratio (GMR) of AUC0 ~ t, AUC0 ~ ∞ and Cmax of zucalatam after oral administration of domestic and imported levetiracetam tablets in healthy male subjects was 90% CI are in the range of 80.00% to 125.00%. Compared with fasting, Tmax prolonged after meal, Cmax decreased, while AUC and t1 / 2 were not different. CONCLUSION: The domestic and imported levetiracetam tablets are bioequivalent under both fasting and postprandial conditions. The bioequivalence test for levetiracetam tablets can only be carried out on a fasting test, and 12 samples can be used.