I have heard a number of FDA audits citing the following deficiency in study design:
Procedures designed to prevent microbiological contamination of drug product purporting to be sterile do not include adequate validation of the sterilization process.
Specifically, inadequate collection filters were used to confirm the retention of Brevundimonas diminuta during the performance of sterilizing filter validation. Pore size of 0.45um collection filters used during the filter validation is rated larger than the microorganism B. diminuta used during the filter validation. Due to the larger pore size of the collection filters, B. diminuta that may have penetrated the 0.22um sterilizing filters may not be detected by the collection filters and result in false negative results
Any thoughts on continued use of 0.45 filter