title: Impact of Sterilization Method on Protein Aggregation and Particle Formation in Polymer-Based Syringes.
abstract: The effects of sterilization methods on the storage stability of erythropoietin (EPO) in polymer-based syringes were assessed by quantifying protein oxidation, aggregation, and particle formation. Micro-particle counting and size exclusion chromatography coupled with a multi-angle light scattering detector demonstrated much lower levels of protein particles and aggregates for EPO stored for 12 weeks in steam-sterilized than in radiation (Rad)-sterilized syringes. Intermediate levels of damage were observed for EPO stored in ethylene oxide-sterilized syringes. HPLC analysis documented that the Rad-sterilized syringes caused increased oxidation of the protein during storage. In contrast, in the steam- and ethylene oxide-sterilized syringes EPO oxidation did not change. Analysis with electron spin resonance revealed that only Rad-sterilized syringes formed radicals in the syringe body, which persisted over the 12-week storage period. These results demonstrated that Rad-sterilization generated radicals in the syringes which in turn caused increased EPO oxidation, particle formation, and protein aggregation. Therefore, steam sterilization was shown to be a preferable sterilization method for the polymer-based syringe system when using biopharmaceutical drugs highly sensitive to oxidation, and particle formation and aggregation.
authors.affiliation: Terumo Corporation, R&D Center, 1500 Inokuchi, Nakai-machi, Ashigarakami-gun, Kanagawa 259-0151, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kiminami
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, 12850 E. Montview Blvd., Aurora, Colorado 80045.
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Krueger
authors.affiliation: Terumo Corporation, R&D Center, 1500 Inokuchi, Nakai-machi, Ashigarakami-gun, Kanagawa 259-0151, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Terumo Corporation, R&D Center, 1500 Inokuchi, Nakai-machi, Ashigarakami-gun, Kanagawa 259-0151, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yoshino
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, 12850 E. Montview Blvd., Aurora, Colorado 80045. Electronic address: John.Carpenter@ucdenver.edu.
authors.forename: John F
authors.initials: JF
authors.lastname: Carpenter
mesh_terms: D004921:Erythropoietin / Q000378:metabolism*; D010084:Oxidation-Reduction; D010316:Particle Size; D011108:Polymers; D066329:Protein Aggregates; D013242:Sterilization / Q000379:methods*; D013594:Syringes / Q000382:microbiology
chemical_list: D011108:Polymers; D066329:Protein Aggregates; D004921:Erythropoietin
keywords: biopharmaceuticals characterization; drug interactions; free radicals; micro-particles; nanoparticles; oxidation; particle size; processing; protein aggregation; stability