目的 对国产重组人促红素注射液（济脉欣）与进口同类型制剂Eprex^®在大鼠体内的药动学进行对比研究，为实现临床替代提供依据。方法 采用¹²⁵I标记示踪方法测定药物浓度，采用DAS2.0进行药动学参数的计算，在大鼠体内分别进行单次sc 2 000 U/kg济脉欣和Eprex^®的血浆药物动力学对比研究、药物组织分布对比研究和尿、粪、胆汁排泄对比研究。结果 大鼠sc相同剂量（2 000 U/kg）的济脉欣和Eprex^®后，RA法所得血浆动力学参数：t_1/2分别为（15.8±1.67）和（15.6±3.15）h；C_max分别为（2 527±471）和（2 470±598）mU/mL；t_max分别为（10.3±1.51）和（9.00±2.45）h；AUC_0-t分别为（64 196±12 544）和（59 630±9 391）mU/mL·h，TCA-RA法所得血浆动力学参数：t_1/2分别为（15.9±4.19）和（16.2±2.45）h；C_max分别为（2 201±584）和（1 907±517）mU/mL；t_max分别为（10.0±1.27）和（9.00±2.45）h；AUC_0-t分别为（53 709±11 992）和（48 519±8 623）mU/mL·h。用RA和TCA-RA法测定济脉欣和Eprex^®给药后2、8、24、36 h各主要脏器及组织药物浓度，显示大部分组织在给药后8 h药物含量最大，然后逐渐降低，各主要脏器及组织药物变化趋势与血浆药物消除一致，没有发现蓄积现象。大鼠sc给药济脉欣和Eprex^®后，在120 h内从尿中分别可回收到给药总量的75.7%和76.2%，在粪中可回收到给药量的14.7%和14.9%。48 h内胆汁排泄量为11.4%和10.3%。结论 国产重组人促红素注射液济脉欣与国外上市制剂Eprex^®大鼠sc给药后，主要药动学参数t_1/2、t_max、C_max和AUC_0-t基本一致，经统计检验无差异；两种制剂在各组织脏器内的暴露以及尿、粪、胆汁排泄对比也无差异。

Objective The pharmacokinetics of domestic recombinant human erythropoietin injection (qimaxin) and imported Eprex^® of the same type in rats were compared to provide a basis for clinical substitution. Methods The drug concentration was determined by ¹²⁵I labeling method. The pharmacokinetic parameters were calculated by DAS 2.0. Plasma pharmacokinetic comparison of sc 2 000 U/kg zymaxin and Eprex^® in rats, comparison of drug tissue distribution, and comparison of urinary, fecal and bile excretion. Results After the same dose (2 000 U/kg) of Jimaixin and Eprex^® were injected subcutaneously in rats, the plasma kinetic parameters obtained by RA method were:t_1/2 were (1.57±1.67) and (15.6±3.15) h, respectively. C_max were (2 527±471) and (2 470±598) mU/mL, respectively. T_max were (10.3±1.51) and (9.00±2.45) h, respectively. AUC_0-t were (64 196±12 544) and (59 630±9 391) mU/mL·h, respectively. Plasma kinetic parameters obtained by TCA-RA. Method t_1/2 were (15.9±4.19) and (16.2±2.45) h, respectively. C_max were (2 201±584) and (1 907±517) mU/mL, respectively. T_max was (10.0±1.27) and (9.00±2.45) h, respectively. AUC_0-t was (53 709±11 992) and (48 519±8 623) mU/mL·h, respectively. The concentrations of major organs and tissues at 2, 8, 24, and 36 h after administration of Jimaixin and Eprex^® were measured by RA and TCA-RA, indicating that most of the tissues had the highest drug content at 8 h after administration, and then gradually decreased. The trend of drug changes in all major organs and tissues were consistent with the elimination of plasma drugs, and no accumulation was observed. After administration of Jimaixin and Eprex^® in SC, rats were able to recover 75.7% and 76.2% of the total dose from the urine within 120 hours, and 14.7% and 14.9% of the dose could be recovered in the feces. The biliary excretion in 48 hours was 11.4% and 10.3%. Conclusion The main pharmacokinetic parameters t_1/2, T_max, C_max and AUC_0-t of the domestic recombinant human erythropoietin injection and the foreign marketed Eprex^® rats were basically the same, and there was no difference by statistical test. There was no difference in the exposure of the two preparations in the organs of each tissue and the comparison of urine, feces and bile excretion.