Buffer Recycling in an Integrated Antibody Downstream Process for Improved Sustainability

The downstream process of monoclonal antibodies (mAbs) is expensive and significantly contributes to overall manufacturing costs. One primary reason is the extensive consumption of water and chemicals required for preparing large volumes of various buffers, essential for multiple chromatography and filtration steps. Reducing the water consumption in biopharmaceutical processes is critical to drive down costs and improve sustainability, which can be achieved through the introduction of buffer recycling. In this study, we implemented buffer recycling in an integrated two-step mAb downstream process consisting of a Protein A capture step in a periodic counter-current (PCC) set-up, followed by a mixed-mode polishing step in flowthrough mode. Buffer recycling was implemented during the cleaning-in-place (CIP) phases of the integrated steps, where the CIP buffer from the polishing column was recovered and reused counter-currently in the CIP phase of the capture column. Compared to the reference process without buffer recycling, this approach resulted in 29% savings in CIP buffer, while maintaining product purity within 0.66% and yield within 1.68% of the reference process. These minor differences confirm that buffer recycling can be implemented without compromising product quality. Through buffer recycling, we see significant potential to improve process sustainability in biomanufacturing by conserving water and reducing chemical waste.