Filter sterilization of products which cannot be sterilized in their final container EUGMP- Annex-1
Questions 1. Products that cannot be sterilized in their final container should be sterilized by:
A) Heat sterilisation
B) Gamma irradiation
C) Filtration through a sterile sterilising-grade filter
D) Autoclaving in bulk
Answer: C
Questions 2. The nominal pore size for a sterilising-grade filter should be a maximum of:
A) 0.45 µm
B) 0.30 µm
C) 0.22 µm
D) 0.10 µm
Answer: C
Questions 3. After sterile filtration, the liquid should be:
A) Immediately frozen
B) Filled aseptically into a previously sterilized container
C) Filled into a non-sterile container and re-filtered
D) Heated to maintain sterility
Answer: B
Questions 4. The selection of the sterilizing filter should ensure:
A) Compatibility with the product
B) Lower cost
C) Faster filtration
D) Higher throughput
Answer: A
Questions 5. Bioburden-reduction prefilters may be used:
A) Only before the final product test
B) At multiple points to control bioburden prior to final filtration
C) Only after the final filtration
D) Only during packaging
Answer: B
Questions 6. An additional sterilising-grade filter close to the point of fill should be considered because:
A) It increases product volume
B) It reduces storage time
C) Sterile filtration carries additional risks
D) It shortens the batch record
Answer: C
Questions 7. The filtration system design should minimise:
A) Operator involvement
B) Fibre and particle generation
C) Filter replacement frequency
D) Batch numbers
Answer: B
Questions 8. Filter characteristics should be compatible with the fluid and:
A) Be able to change pH slightly
B) Not be affected by the product
C) Increase product viscosity
D) Improve product potency
Answer: B
Questions 9. Adsorption of product components and leaching from filter materials:
A) Is always acceptable
B) Should be ignored
C) Must be evaluated
D) Should be corrected post-process only
Answer: C
Questions 10. The filtration system should allow operation within:
A) Vendor temperature limits
B) Validated process parameters
C) Financial budgets
D) Facility HVAC capacity
Answer: B
Questions 11. The filtration system should maintain:
A) Container integrity only
B) Sterility of the filtrate
C) Line speed
D) Filter moisture levels
Answer: B
Questions 12. The number of aseptic connections between the final sterilising filter and filling should be:
A) Maximised
B) Minimized
C) Ignored
D) Increased for redundancy
Answer: B
Questions 13. Integrity testing of the final sterilising filter should preferably be performed:
A) In an open system
B) As a closed system
C) Only post-use
D) Only before cleaning
Answer: B
Questions 14. Sterile filtration must be validated according to:
A) Local environmental regulation
B) Marketing authorization
C) Relevant Pharmacopeia requirements
D) Vendor recommendations only
Answer: C
Questions 15. Validation should be performed under:
A) Best-case conditions
B) Average conditions
C) Worst-case conditions
D) Fastest cycle conditions
Answer: C
Questions 16. For bacterial retention testing, the preferred test material is:
A) Water
B) A surrogate product
C) The actual product being filtered
D) Buffer solution
Answer: C
Questions 17. A surrogate product may be used in bacterial retention testing if:
A) It is cheaper
B) The actual product is unsuitable for the test
C) The batch is too large
D) The real product is hazardous
Answer: B
Questions 18. Filtration parameters to be validated include:
A) Maximum operating pressure
B) Maximum filtration volume
C) Flow rate and temperature
D) All of the above
Answer: D
Questions 19. If integrity testing uses a fluid other than the product, actions must be taken to:
A) Change pH
B) Avoid adverse impact on product quality
C) Increase filtration speed
D) Improve filter wetting time
Answer: B
Questions 20. Critical process parameters, including filtration time and pressure difference, should be recorded in:
A) Maintenance reports
B) Batch records
C) Supplier documentation
D) Cleaning logs
Answer: B
Questions 21. Any significant deviation from critical filtration parameters must be:
A) Ignored
B) Documented and investigated
C) Corrected only in the next batch
D) Reported only to suppliers
Answer: B
Questions 22. PUPSIT refers to integrity testing:
A) Before filter sterilisation
B) After filter removal
C) Pre-use post-sterilisation
D) During product storage
Answer: C
Questions 23. After use, the sterilising-grade filter must undergo:
A) A destructive integrity test
B) No testing
C) A non-destructive integrity test
D) Cleaning validation
Answer: C
Questions 24. Examples of integrity tests include:
A) Bubble point
B) Diffusive flow
C) Water intrusion
D) All of the above
Answer: D
Questions 25. If PUPSIT is not possible, an alternative approach may be taken if:
A) Approved by marketing
B) A thorough risk assessment is performed
C) Production is delayed
D) The filter is very small
Answer: B
Questions 26. Integrity of critical sterile gas and air vent filters should be verified:
A) Before installation only
B) After use
C) Only annually
D) Only during cleaning
Answer: B
Questions 27. Non-critical gas vent filters should be:
A) Tested only after failure
B) Used indefinitely
C) Confirmed and recorded at appropriate intervals
D) Not integrity tested
Answer: C
Questions 28. Liquid sterilising-grade filters should be discarded after:
A) A single batch
B) One month
C) Ten batches
D) One year
Answer: A
Questions 29. Filters may be used for more than one working day only if:
A) Supplier approves
B) Validated
C) Documented in the batch record
D) Cleaned between uses
Answer: B
Questions 30. In campaign manufacture, the maximum validated duration of filter use must be:
A) Estimated
B) Ignored
C) Documented and controlled
D) Left to operator judgement
Answer: C
Reference – EU Guidelines for GMP- Annex-1