Glossary
Sterilising-grade Filter
A filter, normally of a maximum nominal pore size of 0.22 µm, suitably validated to remove microorganisms from a liquid or gas and so give a sterile filtrate.
Details
A sterilising-grade filter is the key microbial barrier for products that cannot be terminally sterilised, so product compatibility, adsorption, extractables, and microbial retention all have to be verified. Inspections cite inadequate control of the compatibility of filter and product, the maximum time, pressure, and volume, the pre-filtration bioburden, and integrity testing. Look at filter validation, the supplier's certificate, the process parameters, PUPSIT and post-use testing, and the batch record.
