To FIT or Not to FIT, That is the Question

Throughout the industry, there are questions regarding when to integrity test filters in the purification and buffer preparation areas. This includes liquid filters as well as vent and air filters. The requirement to warrant a filter integrity test (FIT) is based on compliance with the validated claim of microbial retention and criticality of the filter performance. Filters with no validated retention claim must be evaluated for integrity testing based on the level of risk to product quality and business risk. An approach for determining risk based on filter criticality and location was developed and adopted in a high-volume biopharmaceutical manufacturing plant. The results showed that certain filters might present a high risk to product quality after failure and warranted integrity testing.