Author Archives: Paul Genest

Figure 4: Description of Viresolve Prefilter (left) and Viresolve Pro Shield (right) adsorptive prefilters

Virus-Filtration Process Development Optimization: The Key to a More Efficient and Cost-Effective Step

Size-exclusion–based parvovirus filtration is an important step toward drug product safety in biopharmaceutical production. However, once a virus filter is in place, and the required virus safety is ensured, less attention typically is paid to its optimization within the process. That might seem odd given that virus filtration can be one of the more expensive downstream processing steps ($/g protein processed). Most likely, the lack of attention can be attributed to aggressive timelines, limited process development resources, and the virus…

Impact of Process Interruption on Virus Retention of Small-Virus Filters

Manufacturers of biopharmaceuticals using mammalian cell culture must have processes in place to minimize the likelihood of virus contamination of their products. Regulatory agencies provide guidelines for testing strategies and best practices to assure raw-material safety and control of the manufacturing process. Safety assurance relies on an interdependent matrix of managed risks, including characterization and control of raw materials, extensive testing of process intermediates, and demonstration of the virus removal capabilities of purification unit operations Figure 1:  () A dedicated…

Artifacts of Virus Filter Validation

Virus filters are used in biomanufacturing to ensure the safety of biopharmaceutical drug products. As part of filter implementation, manufacturers are required to validate that the filtration process can indeed remove virus. Validations are typically performed at contract testing organizations (CTOs) that are “equipped for virological work and performed by staff with virological expertise in conjunction with production personnel involved in designing and preparing a scaled-down version of the purification process” (1). Virus removal capability of a filtration process is…

Predicting Virus Filtration Performance with Virus Spike Characterization

Evaluating a virus filter should, in theory, be a straightforward exercise. Membrane-based filtration is a robust virus reduction technology that plays an important role in virus safety for most drug production processes. An appropriate virus filter for a given process is generally selected through preliminary testing with relevant drug feed material. Data acquired during such tests are used to determine hydraulic performance targets such as expected flow rates and total throughputs. A virus clearance evaluation study is then performed in…