title: Capillary Electrophoresis Method for the Assessment of Erythropoiesis-Stimulating Agents in Final Formulations.
abstract: Capillary electrophoresis (CE) comprises several separation modes that can be used to characterize proteins in terms of physico-chemical properties such as isoelectric point or molecular weight, or in terms of purity/heterogeneity for the presence of charge or size variants. In glycoproteins the heterogeneity occurring as a consequence of variable amounts of terminal sialic acid residues on glycan moieties can be detected by CE. As such, a capillary zone electrophoresis (CZE) method was found suitable for the detection of isoforms of several erythropoiesis-stimulating agents (Bietlot and Girard, J Chromatogr A 759:177-184, 1997; Boucher et al., J Pharm Biomed Anal 71:207-213, 2012). In particular, the method can be used to analyze finished products containing erythropoietin-α, erythropoietin-β, or darbepoetin-α regardless of the formulation and without the need for sample pretreatment. The major excipients encountered in the various formulations included polysorbate 80, polysorbate 20, or human serum albumin. The ability of the method to resolve isoforms of the active ingredient in finished product enables the comparison of the isoform profile with that of the corresponding drug substance, allowing the assessment of the structural integrity and content of the active ingredients in finished products.
authors.affiliation: Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, Canada, K1A 0K9. Michel.Girard@hc-sc.gc.ca.
authors.forename: Michel
authors.initials: M
authors.lastname: Girard
authors.affiliation: Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, Canada, K1A 0K9.
authors.forename: Anita
authors.initials: A
authors.lastname: Kane
authors.affiliation: Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, Canada, K1A 0K9.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Boucher
mesh_terms: D000068256:Darbepoetin alfa / Q000737:chemistry / Q000302:isolation & purification; D019075:Electrophoresis, Capillary / Q000379:methods*; D004921:Erythropoietin / Q000737:chemistry / Q000302:isolation & purification; D006397:Hematinics / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D011499:Protein Processing, Post-Translational
chemical_list: C554270:EPO protein, human; D006397:Hematinics; D004921:Erythropoietin; D000068256:Darbepoetin alfa
keywords: Capillary electrophoresis; Darbepoetin; Erythropoiesis-stimulating agent; Erythropoietin; Formulation; Glycoprotein