Abstract: Provided herein are methods of separating host cell lipases from a production protein in chromatographic processes and methods of improving polysorbate-80 stability in a production protein formulation by separating host cell lipases from the production protein using chromatographic processes. Also provided herein are compositions comprising antibodies or antigen binding fragments thereof that bind to cytotoxic T lymphocyte associated antigen 4 (CTLA4). In another aspect, such compositions further comprise a reduced level of host cell proteins and/or increased level of polysorbate-80 (PS-80) stability.

Abstract: Provided herein are methods of separating host cell lipases from a production protein in chromatographic processes and methods of improving polysorbate-80 stability in a production protein formulation by separating host cell lipases from the production protein using chromatographic processes. Also provided are pharmaceutical compositions comprising less than 1 ppm of a host cell lipase.