title: Pharmacokinetics of PEGylated Recombinant Human Erythropoietin in Rats.
abstract: rHuEPO plays a central role as chemicals for the treatment of many diseases. Due to its short half-life, the main aim for this pharmacokinetic study is to investigate a newly developed PEG-rHuEPO with large molecular weight in SD rats. After a single intramuscular administration of different doses of 125I-PEG-rHuEPO, pharmacokinetic parameters, tissue distribution, and excretion were analyzed. In in vivo half-life time measured after 125I-PEG-rHuEPO administration at the doses of 1, 2, and 3 μg/kg, t1/2α was 1.90, 1.19, and 2.50 hours, respectively, whereas t1/2β was 22.37, 26.21, and 20.92 hours, respectively; at 8, 24, and 48 hours after intramuscular administration, PEG-rHuEPO was distributed to all of the examined tissues, however, with high concentrations of radioactivity, only in plasma, blood, muscle at the administration site, and bone marrow. Following a 2 μg/kg single intramuscular administration, approximately 21% of the radiolabeled dose was recovered after almost seven days of study. Urine was the major route of excretion; 20% of the administered dose was recovered in the urine, while excretion in the feces was less than 1.4%. Therefore, this PEG-rHuEPO has potential to be clinically used and could reduce frequency of injection.
authors.affiliation: Isotope Research Laboratory, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Cao
authors.affiliation: Chengdu Institute of Biological Products, Chengdu 610023, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Isotope Research Laboratory, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Zhuoran
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Chengdu Institute of Biological Products, Chengdu 610023, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Ge
authors.affiliation: Isotope Research Laboratory, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Xianyin
authors.initials: X
authors.lastname: Zeng