title: Effect of Osmotic Pressure on the Stability of Whole Inactivated Influenza Vaccine for Coating on Microneedles.
abstract: Enveloped virus vaccines can be damaged by high osmotic strength solutions, such as those used to protect the vaccine antigen during drying, which contain high concentrations of sugars. We therefore studied shrinkage and activity loss of whole inactivated influenza virus in hyperosmotic solutions and used those findings to improve vaccine coating of microneedle patches for influenza vaccination. Using stopped-flow light scattering analysis, we found that the virus underwent an initial shrinkage on the order of 10% by volume within 5 s upon exposure to a hyperosmotic stress difference of 217 milliosmolarity. During this shrinkage, the virus envelope had very low osmotic water permeability (1 - 6×10-4 cm s-1) and high Arrhenius activation energy (Ea = 15.0 kcal mol-1), indicating that the water molecules diffused through the viral lipid membranes. After a quasi-stable state of approximately 20 s to 2 min, depending on the species and hypertonic osmotic strength difference of disaccharides, there was a second phase of viral shrinkage. At the highest osmotic strengths, this led to an undulating light scattering profile that appeared to be related to perturbation of the viral envelope resulting in loss of virus activity, as determined by in vitro hemagglutination measurements and in vivo immunogenicity studies in mice. Addition of carboxymethyl cellulose effectively prevented vaccine activity loss in vitro and in vivo, believed to be due to increasing the viscosity of concentrated sugar solution and thereby reducing osmotic stress during coating of microneedles. These results suggest that hyperosmotic solutions can cause biphasic shrinkage of whole inactivated influenza virus which can damage vaccine activity at high osmotic strength and that addition of a viscosity enhancer to the vaccine coating solution can prevent osmotically driven damage and thereby enable preparation of stable microneedle coating formulations for vaccination.
authors.affiliation: School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Hyo-Jick
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Department of Global Medical Science, Sungshin Women's University, Seoul, Korea.
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Song
authors.affiliation: School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Bondy
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Compans
authors.affiliation: Center for Inflammation, Immunity, & Infection and Department of Biology, Georgia State University, Atlanta, Georgia, United States of America.
authors.forename: Sang-Moo
authors.initials: SM
authors.lastname: Kang
authors.affiliation: School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Prausnitz
mesh_terms: D000818:Animals; D004285:Dogs; D006386:Hemagglutination Tests; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007252:Influenza Vaccines; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D009339:Needles; D009997:Osmotic Pressure; D064166:Vaccine Potency; D014783:Viscosity
chemical_list: D007252:Influenza Vaccines