August 24, 2021: Pharmaceutical Interview Questions and Answers
#FactorsAffectingFilterPerformance #ReplacementOfSterilizationFilters #FrequencyOfEquipmentSterilization
1. What are the factors that can affect filter performance?
Factors that can affect filter performance generally include
(1) Viscosity and surface tension of the material to be filtered,
(2) pH,
(3) Compatibility of the material or formulation components with the filter itself,
(4) Pressures,
(5) Flow rates,
(6) Maximum use time,
(7) Temperature,
(8) Osmolality,
(9) and the effects of hydraulic shock
2. What should be frequency of filter replacement for sterilization filters for product manufacturing?
Sterilizing filters should be routinely discarded after processing of a single lot.
However, in those instances when repeated use can be justified, the sterile filter validation should incorporate the maximum number of lots to be processed.
3. What should be frequency of filter integrity testing?
Integrity testing of the filter(s) can be performed prior to processing, and should be routinely performed post-use. It is important that integrity testing be conducted after filtration to detect any filter leaks or perforations that might have occurred during the filtration.
4. What are the generally used methods for filter integrity testing?
Forward flow and bubble point tests, when appropriately employed, are two integrity tests that can be used.
5. What should be frequency of equipment and accessories sterilization?
Sterility of aseptic processing equipment should normally be maintained by sterilization between each batch.
Reference: FDA Guidance for Industry: Sterile Drug Products Produced by Aseptic Processing – Current Good Manufacturing Practice – September 2004
