Existence of a superior polysorbate fraction in respect to protein stabilization and particle formation?

Biologicals including monoclonal antibodies are the current flagships in pharmaceutical industry. However, they are exposed to a multitude of destabilization conditions like for instance hydrophobic interfaces, leading to reduced biological activity. Polysorbates are commonly applied to effectively stabilize these active pharmaceutical in-gredients against colloidal stress. Nevertheless, chemical instability of polysorbate via hydrolysis or oxidation re-sults in degradation products that might form particles via phase separation. Polysorbates are mixtures of hundreds of individual components, and recently purer quality grades with reduced variations in the fatty acid composition are available. As the protective function of polysorbate itself is not completely understood, even less is known about its individual components, raising the question of the existence of a superior polysorbate species in respect to protein stabilization or degradation susceptibility. Here, we evaluated the protective function of four main fractions of polysorbate 20 (PS20) in agitation studies with monoclonal antibodies, followed by particle analysis as well as protein and polysorbate content determination. The commercially-available inherent mixtures PS20 high purity and PS20 all-laurate, as well as the fraction isosorbide-POE-monolaurate showed superior protection against mechanical-induced stress (visual inspection and turbidity) at the air-water interface in comparison to sole sorbitan-POE-monolaurate,-dilaurate, and -trilaurate. Fractions composed mainly of higher-order esters like sorbitan-POE-dilaurate and sorbitan-POE-trilaurate indicated high turbidities as indication for subvisible and small particles accompanied by a reduced protein monomer content after agitation. For the isosorbide-POE-monolaurates as well as for the inherent polysorbate mixtures no obvious differences in protein content and protein aggregation (SEC) were observed, reflecting the observations from visual appearance. However, absolute polysorbate con-centrations vary drastically between different species in the actual formulations. As there are still open questions in respect to protein specificity or regarding mixtures versus individual components of PS20, further studies must be performed, to gain a better understanding of a generalized stabilizing effect of polysorbates on monoclonal an-tibodies. The knowledge of the characteristics of individual polysorbate species can have the potential to pave the way to superior detergents in respect to protein stabilization and/or degradation susceptibility.

Automated summary

Monoclonal antibodies are widely used in the pharmaceutical industry, but they can be destabilized by various factors, such as hydrophobic interfaces. Polysorbates are commonly used to stabilize these antibodies, but their chemical instability can lead to the formation of particles. In this study, the protective function of different fractions of polysorbate 20 (PS20) was evaluated, and it was found that certain fractions showed superior protection against mechanical-induced stress compared to others. However, further research is needed to understand the specific effects of polysorbates on monoclonal antibodies.