Test Method Validation

Ques:  Test Method Validation, when is it required?  Only on CTQs (critical to quality)?  What is the logic behind determining if its applicable?

Ans:  Whenever you use a test to address a CGMP requirement, it is your responsibility to ensure that the test is appropriate to need and yields accurate results (see US FDA's  Data Integrity Guidance Document).  If it’s defined by a standard, USP, or similar, then it can be used as-is, ‘tho’ I would recommend some minimum verification of your company's usage, documented, initially and periodically to ensure that all variables behave as expected. 

If it’s a variation on an established test, or new / developed in-house, then it would need to be validated. 

If a test is used on CTQs, then the degree of patient risk (e.g. ISO 14971 or ICH Q9) needs to be considered as to the rigor / depth of the validation, and frequency of checks / verifications that the validation does not need to be re-done.  You as a company make these decisions, and document them, though they are subject to challenge by a regulatory inspector.

How your company addresses the above, under what conditions, would be outlined in a company SOP.

-  jel@jelincoln.com