title: Development and calibration of a standard for the protein content of granulocyte colony-stimulating factor products.
abstract: This collaborative study characterizes a homogeneous standard for the protein content determination of granulocyte colony-stimulating factor (G-CSF) products with traceability of the measurement. The Kjeldahl method was used to determine the average protein content of G-CSF bulk as 2.505 mg/ml (95% C.I: 2.467-2.543 mg/ml, GCV 4.0%). Using G-CSF bulk as a traceability benchmark, the protein content of the final freeze-dried standard using reverse phase HPLC (RP-HPLC) was 215.4 μg protein per ampoule (95% C.I: 212.407-218.486 μg/ampoule, GCV 3.4%). A comparative study showed that there was no difference between using Filgrastim CRS (European Pharmacopeia G-CSF reference standard) and freeze-dried homogeneous standard when quantifying G-CSF protein content by RP-HPLC (P > 0.05). However, there were significant differences in the G-CSF protein content obtained using a serum albumin standard by Lowry assay and a G-CSF standard with RP-HPLC. Therefore, use of RP-HPLC with a freeze-dried homogeneous standard would eliminate the systematic errors introduced when using a serum albumin standard because of the differences in protein composition between the standard and the sample. It would also be helpful to use this method to compare the quality of G-CSF biosimilar products in situations where the protein content has been calibrated using various standards.
authors.affiliation: National Institute for the Control of Pharmaceutical and Biological Products, No.2, Tiantan Xili, Beijing 100050, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Gao
authors.forename: Chunming
authors.initials: C
authors.lastname: Rao
authors.forename: Lei
authors.initials: L
authors.lastname: Tao
authors.forename: Chunmei
authors.initials: C
authors.lastname: Han
authors.forename: Xinchang
authors.initials: X
authors.lastname: Shi
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.forename: Wenhong
authors.initials: W
authors.lastname: Fan
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.forename: Junzhi
authors.initials: J
authors.lastname: Wang
mesh_terms: D059451:Biosimilar Pharmaceuticals / Q000032:analysis* / Q000592:standards*; D000069585:Filgrastim; D005612:Freeze Drying; D016179:Granulocyte Colony-Stimulating Factor / Q000032:analysis* / Q000592:standards*; D006801:Humans; D055550:Protein Stability; D011506:Proteins / Q000032:analysis / Q000592:standards; D011786:Quality Control; D011994:Recombinant Proteins / Q000032:analysis / Q000592:standards; D012015:Reference Standards; D012709:Serum Albumin / Q000032:analysis / Q000592:standards
chemical_list: D059451:Biosimilar Pharmaceuticals; D011506:Proteins; D011994:Recombinant Proteins; D012709:Serum Albumin; D016179:Granulocyte Colony-Stimulating Factor; D000069585:Filgrastim