Starting from this lesson, we will enter the unit on sterile filtration validation, which is of greatest concern to everyone.
Generally speaking, sterile filtration validation comprises two parts: performance qualification of the sterile filter itself and filtration process validation. Performance qualification of the sterile filter and filtration process validation are difficult to substitute for one another and should be conducted independently.
The performance qualification of the sterile filter itself is typically completed by the filter manufacturer. Key qualification items include microbial retention testing, integrity testing, biosafety testing (toxicity testing and endotoxin testing), flow rate testing, water pressure testing, multiple sterilization testing, extractables testing, particulate release testing, and fiber shedding testing.
Filtration process validation refers to the validation process conducted for a specific medium to be filtered, in conjunction with specific process conditions. It generally includes bacterial retention testing, chemical compatibility testing, extractables or leachables testing, safety assessment, and adsorption assessment. If integrity testing is performed using the product as the wetting medium after filtration, relevant product integrity test validation should also be conducted. Sterile filtration process validation can be performed by the filter user or a commissioned testing agency (e.g., the filter manufacturer or a third-party laboratory). However, the filter user must ultimately ensure that the operating parameters and allowable extremes in actual production have been covered during validation, with corresponding supporting documentation.
So, what do these qualification and validation items represent, and why should they be carried out by different responsible parties?
For review, please click: What validations and qualifications should filter manufacturers perform?
Validation documents from different filter manufacturers are generally not interchangeable. Even validation documents for sterile filters of the same material from the same manufacturer often cannot be directly substituted unless supported by a reasonable statement or documentation. If two or more filters from different manufacturers, or filters of the same material (with different membrane formation processes) from the same manufacturer, are used during production, validation should be conducted separately.