Diffusive airflow integrity testing.
The more certain implications to retention based upon definition of the largest pores present in a filter may be had where bubble point testing is possible. Where diffusive airflows interfere with bubble point determinations, the diffusive airflow measurements themselves, correlated to organism retentions, serve as integrity tests. Diffusive airflow measurements have their advantage in addition to serving as indicators of filter integrity. They can more precisely reveal filter incompatibilities. They can be used to gauge the completeness of a filter's wettability, and they are more revealing of a filter's clean water flow properties. In almost all its applications, however, diffusive airflow integrity testing requires defining the diffusive airflow curve by way of multipoint measurements using the liquid product in question. This is especially true in filter validation contexts where product-specific testing is necessitated. Once the full diffusional airflow curve has been elucidated, single-point diffusional flow testing is warranted, as in production integrity testing settings. Single point diffusive flow testing can be used as a standard integrity test method for use in the pharmaceutical production environment.