Freeze/thaw of IGG solutions
Jacqueline Horn, Sampeeti Jena, Alptekin Aksan, Wolfgang Friess
European Journal of Pharmaceutics and Biopharmaceutics
In this communication, the effect of mannitol and trehalose crystallization on the unfolding of IgG1, a monoclonal antibody, in the frozen state with repeat freeze/thawunder different pH conditions was explored. Formulations were annealed at −20 °C for 20 h five times (interrupted by freeze/thaw). This was done to induce excipientcrystallization. Characterization of the frozen-thawed samples was performed by circular dichroism, particle analysis, and size exclusion chromatography. At a pH of 3, formation of insoluble and soluble aggregates was observed however, these could be reduced by the use of a surfactant. Cryoprotectant free formulations showed higher monomer content after freeze/thaw. At pH 5, a single freeze/thaw cycle did not result in a significant increase in particle numbers. At pH range of 4–7 however, aggregate formation in the size range of 1–25 µm was observed after 5 freeze/thaw cycles.
Circular dichroism, Secondary structure, Chemical stability, Antibodies, Biochemistry, Pharmaceutical