With the development and manufacture of subcutaneous biologics come challenges in the sterilizing or bioburden reduction filtration of drug substance that is both highly concentrated (100 g/L) and viscous (10-30 cP). Two significant problems are:
- The use of larger filters as a consequence of the high fouling properties of the feeds. This results in the loss of high value drug substance in hold-up volumes in both the filtration assembly and system.
- The relative scarcity of product during process development. This results in limited opportunities for meaningful filter benchmarking studies and can lead to sub-optimal filter selection.
In this presentation we share the approach we took to develop a new sterilizing grade filter for high concentration biologics, which allowed us to undertake extensive filterability trials without the need to generate a high quantity of expensive product.