S166: Implementation of harvested cell culture fluid (HCCF) air sparging to prevent antibody disulfide bond reduction

During the scale-up of a CHO monoclonal antibody production process, significant reduction of the antibody’s disulfide bonds was observed due to cellular factors released upon mechanical shear in the course of the harvest operations.  Several methods to prevent this antibody reduction event were identified including maintaining the dissolved oxygen in the HCCF at a level which prevents reduction via air sparging.  A small-scale model was developed to test multiple air sparging strategies for effectiveness and potential impact to product quality.  The results of these studies showed that air sparging is robust and may be a universal method to prevent disulfide bond reduction across multiple products.  HCCF air sparging was subsequently implemented successfully in several manufacturing-scale processes.  Additional investigations into correlations between the number of lysed cells, oxygen consumption and disulfide bond reduction will also be discussed.