Virus filtration using small pore virus filter in downstream processing of biotherapeutic products: The effect of operating pressure

Virus filtration is a robust and effective method to remove potential virus contaminants. Planova 20 N, a virus filter form Asahi Kasei Bioprocess, has been widely used in the manufacturing process of biotherapeutics. Previous studies have shown that parvovirus removal by Planova 20 N can be impacted by low operation pressure and depressurization. Therefore, it is critical to define an operating pressure range for robust virus removal. In this work, the effect of pressure combined with depressurization on virus removal by Planova 20 N was investigated. Our studies showed that effective virus removal can be achieved in the pressure range from 0.7 bar to 1.6 bar. The data also suggest that re-starting with higher pressure after depressurization is highly desirable for large-scale manufacture to mitigate virus leakage risk. In addition, skipping buffer flush post mainstream filtration minimizes the likelihood of depressurization.