Reduce Consumable Expenses with Continuous Purification

Significant cost savings are commonly advertised for continuous biopharmaceutical processes, but where they come from is not always immediately apparent. Continuous purification processes generate major savings from consumable cost reductions – specifically resin – and capital equipment expenditures. We will dive a little deeper into the first of these scenarios here.

Resin cost savings are primarily achieved with a reduction in protein A resin volumes, as this is by far the most expensive resin on the market. Continuous processes provide resin savings for products that typically do not run enough batches to reach resin lifetimes before expiry. A continuous process will often be designed to run slowly over several days to weeks rather than quickly in an 8-to-12-hour shift. As a result, smaller columns are used for a greater number of cycles when compared to a batch process. To purify 1 Kg of mAb a week, we can use a 4.4 cm diameter column instead of a 20 cm diameter column, with less than 5% of the resin volume. Importantly, a process can be designed so that the duration of the process nears the lifetime of the resin to ensure its full value is utilized.

A second way to achieve resin cost savings is with a multi-column chromatography system that connects multiple columns in series. With this setup, the first chromatography column can be loaded to capacity without a loss in yield that would typically be experienced due to product breakthrough – any breakthrough binds to the second column in series. Therefore, a safety factor for resin capacity is no longer needed.  As a result, a lower resin volume can be used for a given batch size.

Resin cost savings are a large driver for continuous purification processes in both existing and new facilities. See our article on equipment cost savings for new facilities.