title: Determination of KRN321 in rat serum by ELISA and correlation between ELISA and in vitro bioassay.
abstract: KRN321, darbepoetin alfa, is a hyperglycosylated analog of recombinant human erythropoietin (rHuEPO, epoetin alfa). We carried out the validation study by using a commercially available ELISA assay kit to establish the ELISA quantitation method for KRN321 in rat serum for the implementation of the pharmacokinetic studies with a lower limit of quantitation at 100 pg/mL and quantitation range from 100 to 4,000 pg/mL. We also established the in vitro bioassay method as an index of biological activity using UT-7/Epo, derived from a human leukemia cell line with a lower limit of quantitation, at 10 ng/mL. Furthermore, good correlation was observed between the two methods; it indicated that KRN321 concentration determined by the ELISA maintained biological activity.
authors.affiliation: Pharmaceutical Development Laboratories, Pharmaceutical Division, Kirin Brewery Co. Ltd., 2-2 Souja-machi 1-chome, Maebashi, Gunma 371-0853, Japan. eyoshioka@kirin.co.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Yoshioka
authors.forename: Kanako
authors.initials: K
authors.lastname: Kato
authors.forename: Masumi
authors.initials: M
authors.lastname: Tanabe
authors.forename: Tadashi
authors.initials: T
authors.lastname: Misaizu
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ogata
mesh_terms: D000818:Animals; D001681:Biological Assay; D045744:Cell Line, Tumor; D000068256:Darbepoetin alfa; D004355:Drug Stability; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004921:Erythropoietin / Q000031:analogs & derivatives* / Q000097:blood; D005615:Freezing; D006801:Humans; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000097:blood; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D011994:Recombinant Proteins; D004921:Erythropoietin; D000068256:Darbepoetin alfa