Polysorbate-80 (PS-80) and polysorbate-20 (PS-20) are used widely in formulation of biotherapeutic products for preventing surface adsorption and as stabilizers against protein aggregation (1). Degradation of polysorbates can cause turbidity and potential formation of subvisible particles mainly consisting of poorly soluble hydrophobic free fatty acids (1). Polysorbate degradation is an industry-wide challenge both in biotherapeutics processing and formulation development. The risk of such degradation increases with higher cell densities and greater expression titers in bioprocessing, as well as with higher…