H. Jurgen Spanier

Testing sterilizing grade filters using integrity testers has become a standard method in biopharmaceutical production and quality assurance. In accordance with international regulations and recommendations, these filters should be tested before and after filtration. For these applications, a variety of automatic integrity testers is available. Currently, there are two groups of devices that are used to conduct validated testing procedures, such as the bubble point test, the diffusion test, and the water intrusion test (WIT) and water flow test (WFT). Whereas one group of devices relies on the principle of flow measurement, the other group is based on pressure drop measurements. The following report compares the accuracy of the two test methods, using the WFT as a reference.