title: Strategy for assessment of the colloidal and biological stability of H1N1 influenza A viruses.
abstract: Current influenza vaccines are mostly formulated as liquids which requires a continuous cold chain to maintain the stability of the antigen. For development of vaccines with an increased stability at ambient temperatures, manifold parameters and their influences on the colloidal stability and activity of the antigen have to be understood. This work presents a strategy to examine both, the colloidal stability and the remaining biological activity of H1N1 influenza viruses under various conditions after an incubation of 40 days. H1N1 phase diagrams were generated for several pH values and different initial H1N1 and NaCl concentrations. It was shown that the highest H1N1 recoveries were obtained for pH 6 and that moderate amounts of NaCl are favorable for increased recoveries. In contrast to colloidal stability, the highest remaining HA activity was observed at pH 9. The electrostatic and hydrophobic surface properties of H1N1 were investigated to reveal the mechanisms accounting for the decrease in stability. Secondly, the capability of virus precipitation by polyethylene glycol in combination with determination of surface hydrophobicity was proven to be useful as a predictive tool to rank stability under different conditions. This methodology enables the rapid assessment of aggregation propensity of H1N1 formulations and the influence on the activity of the virus particles and might become a standard tool during the development of vaccine formulations.
authors.affiliation: Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. Electronic address: frank.haemmerling@kit.edu.
authors.forename: Frank
authors.initials: F
authors.lastname: Hämmerling
authors.affiliation: Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. Electronic address: uajgu@student.kit.edu.
authors.forename: Oliver
authors.initials: O
authors.lastname: Lorenz-Cristea
authors.affiliation: Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. Electronic address: pascal.baumann@kit.edu.
authors.forename: Pascal
authors.initials: P
authors.lastname: Baumann
authors.affiliation: Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. Electronic address: juergen.hubbuch@kit.edu.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hubbuch
mesh_terms: D003102:Colloids; D004339:Drug Compounding; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry* / Q000276:immunology*; D007252:Influenza Vaccines / Q000737:chemistry*; D009994:Osmolar Concentration; D055672:Static Electricity; D013499:Surface Properties; D064166:Vaccine Potency; D014613:Vaccines, Attenuated
chemical_list: D003102:Colloids; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated
keywords: Formulation; Pandemic influenza virus; Stability; Surface properties; Virus phase diagram