Comprehensive investigation of factors influencing the degradation of polysorbate 20: Insights into mechanisms and interactions using a design of experiments approach

This study investigates the degradation of polysorbate 20 (PS20 HP) in a protein-free formulation under various storage conditions, examining the factors (i) Fe 2+ , (ii) Fe 3+ , (iii) H 2 O 2 , (iv) glass vial type, (v) fill volume, (vi) oxygen concentration, (vii) PS20 HP batches, (viii) light exposure before storage, and (ix) storage time by a design of experiments approach. In order to ascertain the impact of the factors under examination, realistic concentration ranges have been selected on the basis of observations made in industrial settings. The findings of our investigation demonstrate that the presence of Fe 2+ and Fe 3+ , in addition to oxygen, has a significant influence on the degradation of PS20 HP, with Fe 2+ exerting a more pronounced effect. The reduction of the oxygen content through nitrogen degassing has been demonstrated to have a pronounced inhibitory effect on PS20 HP degradation, even in the presence of iron ions. Interestingly, the concentration of intact PS20 HP was not significantly affected by H 2 O 2 (tested concentration: 29.4 μM (1 ppm)). Furthermore, other factors including fill volume, PS20 HP batch, and light exposure, did not exert a statistically significant impact on the degradation of PS20 HP over a 12-month period in relation to the other factors.