This document provides background information on virus filtration retention using Viresolve® Pro devices. The term device will be used when specifically describing the Viresolve® Pro virus filter. The terms used in this document are consistent with the Quality by Design (QbD) approach to improved process understanding. This document is intended to consolidate a body of virus retention results on Viresolve® Pro devices and to communicate these results to help biologics manufacturers understand the parameters that might impact Viresolve® Pro device performance.
Virus filtration is a critical operation in many biologic production processes and a key component of most viral safety strategies. A virus filter is a robust technology for removing viruses of different sizes. Virus removal across filters is based on the principles of size exclusion. Viresolve® Pro devices are released to a specification that provides at least 4.0 logs of small virus, such as parvovirus, removal.
This document provides information on virus retention performance of Viresolve® Pro devices and is framed in the context of a process design space within which the filters would be expected to operate. Scope is limited to operation of Viresolve® Pro devices and the information provided should not be extended to characterize performance of other virus filters. This information should be considered relevant if prefilters are used with Viresolve® Pro devices. Information summarized in this document increases process understanding with Viresolve® Pro devices and is intended to guide risk assessments associated with product characterization studies as outlined in ICH Q9.
Understanding the impact of the system, operating and process parameters on virus retention performance of the virus filter helps rank the risk posed by different process parameters, identify control strategies for high risk parameters, and guide validation study design.
Most studies in this document evaluated retention performance of small virus, e.g. parvovirus such as Minute virus of Mice (MVM), on Viresolve® Pro devices, as these represent perhaps the most challenging adventitious viral agents for removal based on size. Some test conditions were evaluated using bacteriophage ϕX-174, an industry accepted model for parvovirus, which is used for quality release of Viresolve® Pro membrane and devices.