Depth filters are widely used in the biopharmaceutical industry. They are typically made of a mixture of cellulose, filter aids, and a binder. These components can be milled and mixed in different ratios to target a wide range of pore sizes. The complex nature of the raw materials gives each filter a relatively broad pore size distribution and provides some adsorptive capacity through charge and hydrophobic interactions. The filter media thickness, pore size distribution, and adsorptive capacity make them the ‘go-to’ technology in harvest applications where a product is separated from a complex cell culture fluid.
Recent work has highlighted the importance of how capsule design can affect scalability of depth filters. In this work, we present scalability data across a full range of process development-scale, pilot-scale, and manufacturing-scale depth filter capsules. Analysis includes pressure profiles, turbidity and particle reduction, yields, and impurity removal. This data will help process development scientists and engineers understand the structure of these devices, what parameters to focus on during development, and how to set appropriate safety factors during scale-up.
