title: Stabilization of a recombinant ricin toxin A subunit vaccine through lyophilization.
abstract: Lyophilization was used to prepare dry, glassy solid vaccine formulations of recombinant ricin toxin A-chain containing suspensions of colloidal aluminum hydroxide adjuvant. Four lyophilized formulations were prepared by using combinations of rapid or slow cooling during lyophilization and one of two buffers, histidine or ammonium acetate. Trehalose was used as the stabilizing excipient. Aggregation of the colloidal aluminum hydroxide suspension was reduced in formulations processed with a rapid cooling rate. Aluminum hydroxide particle size distributions, glass transition temperatures, water contents, and immunogenicities of lyophilized vaccines were independent of incubation time at 40 °C for up to 15 weeks. Mice immunized with reconstituted ricin toxin subunit A (RTA) vaccines produced RTA-specific antibodies and toxin-neutralizing antibodies (TNAs) regardless of the length of high temperature vaccine storage or the degree of aluminum adjuvant aggregation that occurred during lyophilization. In murine studies, lyophilized formulations of vaccines conferred protection against exposure to lethal doses of ricin, even after the lyophilized formulations had been stored at 40 °C for 4 weeks. A corresponding liquid formulation of vaccine stored at 40 °C elicited RTA-specific antibody titers but failed to confer immunity during a ricin challenge.
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado, Boulder, USA.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Hassett
authors.forename: Megan C
authors.initials: MC
authors.lastname: Cousins
authors.forename: Lilia A
authors.initials: LA
authors.lastname: Rabia
authors.forename: Chrystal M
authors.initials: CM
authors.lastname: Chadwick
authors.forename: Joanne M
authors.initials: JM
authors.lastname: O'Hara
authors.forename: Pradyot
authors.initials: P
authors.lastname: Nandi
authors.forename: Robert N
authors.initials: RN
authors.lastname: Brey
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Mantis
authors.forename: John F
authors.initials: JF
authors.lastname: Carpenter
authors.forename: Theodore W
authors.initials: TW
authors.lastname: Randolph
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology; D000277:Adjuvants, Pharmaceutic / Q000737:chemistry / Q000494:pharmacology; D000536:Aluminum Hydroxide / Q000737:chemistry; D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology; D002021:Buffers; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004355:Drug Stability; D004356:Drug Storage; D005079:Excipients / Q000737:chemistry; D005260:Female; D005612:Freeze Drying / Q000379:methods; D006358:Hot Temperature; D051379:Mice; D010316:Particle Size; D011994:Recombinant Proteins / Q000737:chemistry* / Q000276:immunology; D012276:Ricin / Q000737:chemistry* / Q000276:immunology; D044366:Transition Temperature; D014199:Trehalose / Q000737:chemistry; D022223:Vaccines, Subunit / Q000737:chemistry* / Q000276:immunology; D014867:Water / Q000737:chemistry
chemical_list: D000276:Adjuvants, Immunologic; D000277:Adjuvants, Pharmaceutic; D057134:Antibodies, Neutralizing; D002021:Buffers; D005079:Excipients; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D014867:Water; D000536:Aluminum Hydroxide; D012276:Ricin; D014199:Trehalose
keywords: Adjuvant; Aggregation; Aluminum; Biodefense; Freeze drying; Lyophilization; Ricin; Stability; Vaccine