Comparative Stability Study of Polysorbate 20 and Polysorbate 80 Related to Oxidative Degradation

The surfactants polysorbate 20 (PS20) and polysorbate 80 (PS80) are utilized to stabilize protein drugs. However, concerns have been raised regarding the degradation of PSs in biologics and the potential impact on product quality. Oxidation has been identified as a prevalent degradation mechanism under pharmaceutically relevant conditions. So far, a systematic stability comparison of both PSs under pharmaceutically relevant conditions has not been conducted and little is known about the dependence of oxidation on PS concentration. Here, we conducted a comparative stability study to investigate (i) the different oxidative degradation propensities between PS20 and PS80 and (ii) the impact of PS concentration on oxidative degradation. PS20 and PS80 in concentrations ranging from 0.1 mg & sdot;mL(-1) to raw material were stored at 5, 25, and 40 degree celsius for 48 weeks in acetate buffer pH 5.5 and water, respectively. We observed a temperature-dependent oxidative degradation of the PSs with strong (40 degree celsius), moderate (25 degree celsius), and weak/no degradation (5 degree celsius). Especially at elevated temperatures such as 40 degree celsius, fast oxidative PS degradation processes were detected. In this case study, a stronger degradation and earlier onset of oxidation was observed for PS80 in comparison to PS20, detected via the fluorescence micelle assay. Additionally, degradation was found to be strongly dependent on PS concentration, with significantly less oxidative processes at higher PS concentrations. Iron impurities, oxygen in the vial headspaces, and the pH values of the formulations were identified as the main contributing factors to accelerate PS oxidation.

Automated summary

A comparative stability study was conducted to investigate the oxidative degradation tendencies of surfactants polysorbate 20 (PS20) and polysorbate 80 (PS80) at different concentrations stored for 48 weeks at varying temperatures. PS80 showed stronger degradation and earlier onset of oxidation compared to PS20, with significantly less oxidative processes observed at higher PS concentrations. Iron impurities, oxygen in the vial headspaces, and the pH values of the formulations were identified as main contributing factors to accelerate PS oxidation.