Brij-58, a potential injectable protein-stabilizer used in therapeutic protein formulation

Polysorbates (PSs) are common protein stabilizers used in biotherapeutic formulations. However, PSs are heterogeneous and unstable in liquid protein formulations [1,2]. The purpose of this work is to explore possible alternatives for polysorbate replacements that demonstrate superior protein protection, superior self-stability, low toxicity, and wide applicability. For this purpose, 8 non-ionic surfactants that have not yet been used as excipients in marketed biotherapeutic products were investigated with PS20/80 as the benchmark. Compared with PS20/80, Brij-58 showed better protein protection ability in the mAb1 formulation under forced degradation conditions when examined by visual inspection, SEC, and dynamic lighting scanning. Additionally, Brij-58 has a better inherent stability than PS20/80 in the protein formulation when detected by UPLC-CAD. Moreover, Brij-58 is an inert excipient that does not affect protein bioactivity and conformation. In addition, the LD50 and hemolysis concentration of Brij-58 were determined, which is relatively safe when used as a parenteral injection. Furthermore, Brij-58 was also an effective protein stabilizer for the other two antibody products (IgG4 subtype and bispecific antibody) in the shaking study. In summary, Brij-58 stands out as a promising PS replacement in biotherapeutic formulations with a safe, stable and effective protein-protection profile among candidate surfactants.