How to use this document
Copy the template below into your quality system. Replace every <<FILL: ...>> placeholder with your company, system, and process specifics, then route it through your own document control, review, and approval. The filled specimen shows one worked example; adapt the numbers and scope to your operation and verify each cited regulation or standard against the current source before you rely on it.
This is a generic, originally worded starting point. It contains no confidential, proprietary, or employer material, it is drafted with AI assistance and reviewed, it is not legal or compliance advice, and adopting it does not by itself create or prove compliance. See the Disclaimer and Terms.
This is a ready-to-use validation plan for two sterilizing-grade filters run in series, built to prevent the common gap where only one position in a redundant pair carries its own bacterial retention and integrity test validation. Replace every <<FILL: ...>> placeholder with your own specifics and route it through your normal document control, review, and approval. A worked filled specimen follows. Verify each cited reference against the current source before you rely on it.
1. Purpose
This plan defines how each position in a two-filter series is independently validated for bacterial retention and physical integrity, and states whether the sterility claim for <<FILL: product>> rests on the combined system or on each filter independently.
2. Scope
3. Responsibilities
4. Sterility claim basis
5. Per-position validation requirements
6. Acceptance criteria
7. Deviation handling
A failed integrity test or an out-of-specification retention result at either position is a deviation regardless of the other position’s result. State in the deviation record whether the sterility claim basis in section 4 allows the batch disposition sought, or whether an independent-basis claim requires treating the failure as batch-affecting regardless of the other filter’s performance.
8. Summary and conclusion
State plainly whether both positions are qualified, what the approved sterility claim basis is, and whether routine manufacture may proceed on this basis.
9. References
ASTM F838, Standard Test Method for Determining Bacterial Retention of Membrane Filters Utilized for Liquid Filtration.
PDA Technical Report No. 26, Sterilizing Filtration of Liquids.
EU GMP Annex 1 (2022), Manufacture of Sterile Medicinal Products.
Confirm the current version of each reference before issue.
10. Revision history
11. Approvals
Filled specimen
Extract for an example patient-specific cell therapy fill step where the batch cannot be remade. Company, product, and numbers are illustrative.
Both positions passed their independent retention and integrity correlation studies. Conclusion: both filters qualified on an independent-per-filter sterility claim basis; routine manufacture may proceed under this plan.
Common inspection findings this plan prevents
- A redundant pair where only the downstream filter carries a bacterial retention study, the upstream filter assumed covered by “redundancy.”
- No stated basis for whether the sterility claim rests on the combined system or on each filter independently.
- PUPSIT considered once for the pair rather than assessed at each position separately.
- A failed integrity test at one position dispositioned without reference to the approved sterility claim basis.
How to adapt this plan
- Set your document number, filter models, and the reason redundancy was adopted in the header.
- Decide and document the sterility claim basis in section 4 before either position is tested.
- Populate section 5 with each position’s own bioburden/particulate reality; do not assume they match.
- Reference the paired PUPSIT justification separately for each position where PUPSIT applies.
