title: Effect of pH on stability of recombinant botulinum serotype A vaccine in aqueous solution and during storage of freeze-dried formulations.
abstract: The purpose of this study was to evaluate the importance of prelyophilization solution pH on the stability of botulinum neurotoxin, serotype A (rBoNTA(H(c))). This understanding is of significant importance for proteins such as rBoNTA(H(c)), a potential constituent of a multivalent vaccine product. For multivalent vaccines it may be difficult to identify a liquid formulation satisfying the stability requirements for all constituent protein antigens. Consequently, a lyophilized multivalent vaccine formulation may be a more viable alternative. Therefore evaluating the effect of prelyophilization pH (may be suboptimal) on the stability of antigens such as rBoNTA(H(c)) during lyophilization/storage becomes important. We hypothesize that when rBoNTA(H(c)) is lyophilized from a suboptimal pH, using the appropriate stabilizers can provide adequate physicochemical stability during lyophilization and long-term storage. We identified pH 5 and 8 in which the protein was stable and unstable against aggregation. Excipients were identified that could stabilize rBoNTA(H(c)) during lyophilization and storage in a stable solution of pH 5. These excipients were 7.5% (w/v) trehalose and 2.5% (w/v) trehalose with 2.5% (w/v) HES, with and without 0.01% (w/v) polysorbate 20. In support of our hypothesis, these excipients were found to provide adequate physicochemical stability to rBoNTA(H(c)) during lyophilization/storage, when freeze-dried from a prelyophilized solution of pH 8.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
authors.forename: Shouvik
authors.initials: S
authors.lastname: Roy
authors.forename: Ian
authors.initials: I
authors.lastname: Henderson
authors.forename: Rajiv
authors.initials: R
authors.lastname: Nayar
authors.forename: Theodore W
authors.initials: TW
authors.lastname: Randolph
authors.forename: John F
authors.initials: JF
authors.lastname: Carpenter
mesh_terms: D001428:Bacterial Vaccines / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003014:Clostridium botulinum / Q000276:immunology*; D004355:Drug Stability; D005612:Freeze Drying; D006863:Hydrogen-Ion Concentration; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D001428:Bacterial Vaccines; D011994:Recombinant Proteins