When Should Filter Validation Be Performed?

Regardless of the clinical phase a drug product is in, it is expected that the end-user ensures the product aligns with predefined characteristics in terms of strength, identity, purity, and quality. For drug products that cannot undergo terminal sterilization, sterilizing grade filters are typically used to achieve sterility. Before producing a drug product for early-phase clinical trials, the justification for selecting a sterilizing grade filter should be documented as part of the contamination control strategy (CCS).

As the drug product advances through clinical trials, both product and process understanding evolve in tandem. Although product and process-related filter validation studies must eventually be conducted, no specific guidance dictates when these studies should occur. Therefore, the timing of filter validation is largely determined by the end-user. While many end-users choose to conduct process-specific filter validation testing during Phase 3 clinical trials, risk assessment should be employed to identify and address any risks uncovered during process development. Continue reading to learn about a program that has been developed to facilitate risk mitigation before process-specific filter validation is performed.