Pharmacokinetics of PEGylated recombinant human erythropoietin in rats

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 g/kg,t1/2 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 g/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. © 2014 xiaohan cao et al.