CONSIDERATIONS ON RE-USE OF STERILIZING-GRADE FILTERS

Membrane filters designed to sterilize liquids and gases have performed successfully in a broad range of process applications. As economic and market conditions lead pharmaceutical, biotechnology and vaccine manufacturers to search for ways to improve profitability by decreasing process costs, re-using sterilizing-grade filters may be considered. Although liquid sterilizing-grade filters are generally developed and recommended for single batch or campaign use, there are many applications where they may be subjected to multiple usages (i.e. re-use). This article focuses on the re-use of hydrophilic- or hydrophobic-membrane sterilizing-grade filters applied in liquid sterilizing applications. The author reviews different approaches that may be defined as re-use, discusses factors to consider when deciding whether to re-use sterilizing-grade filters and provides a case study that highlights potential risks and considerations for process validation in filter re-use applications. Suitability of re-use of sterilizing-grade filters in liquid sterilization applications ultimately depends upon the requirements of the specific application, the supplier's core filter product validation studies and the end user's filtration process validation. This evaluation includes assessments of re-use risk and effects that may compromise the filter's ability to completely retain bacteria and thus sterilize the process fluid.