Articles
RSSA Parametric Approach To Filter Validation For The Pharmaceutical & Biopharmaceutical Industries
August 31, 2004
Microbiological Challenge Testing
All Pall 0.2 and 0.1 micron rated sterilizing grade filters are validated against the standard challenge organism Brevundimonas diminuta (previously known as Pseudomonas diminuta), under controlled laboratory conditions based on ASTM standard methodology. The FDA Guidelines on Aseptic Processing define a sterilizing grade filter as: "A filter which, when challenged with the microorganism Pseudomonas diminuta at a minimum concentration of 107/cm2 of filter surface, will produce a sterile effluent."
All Pall 0.2 and 0.1 micron rated sterilizing grade filters are validated against the standard challenge organism Brevundimonas diminuta (previously known as Pseudomonas diminuta), under controlled laboratory conditions based on ASTM standard methodology. The FDA Guidelines on Aseptic Processing define a sterilizing grade filter as: "A filter which, when challenged with the microorganism Pseudomonas diminuta at a minimum concentration of 107/cm2 of filter surface, will produce a sterile effluent."
Although B. diminuta (ATCC19146) is the reference organism, it is not the smallest bacterium and may not always represent the worst case in a given process. Process validation, therefore, requires that the potential bioburden be assessed to ensure that an appropriate grade of filter has been selected. Bacterial challenge tests are then conducted using B. diminuta to verify that the filter will achieve sterility under process conditions. The question to be answered is: "Does the product or process affect the filter or the bioburden in such a way that sterility may not be achieved?"
