Question 5 of 6 Advanced Concept
What is the connection between critical process parameters and product attributes?
Short answer
A critical process parameter is a process variable whose variability can affect a critical quality attribute and therefore needs an appropriate level of control.
Why
Start with patient-relevant and product-relevant quality attributes such as purity, potency or glycosylation profile for a biologic. Use experimental designs and prior process knowledge to understand which parameters influence them, including interactions and time dependence. A chromatography load or elution condition may affect impurity removal, but the criticality conclusion requires evidence and scientific rationale rather than merely a strong correlation in a small dataset.
Establish operating and control ranges, monitoring and a plan for excursions. Not every logged variable is a CPP, and a parameter may be critical only under certain material conditions or process stages. Maintain documented relationships as knowledge grows.
An acceptable final product measurement should not obscure a process mechanism that could fail in future lots.
Common mistakes
- Labeling every monitored sensor as critical without linking its variability to a quality attribute
The interviewer might ask next
What experiment would demonstrate that a parameter genuinely drives impurity clearance?