Validation of Analytical Assays and Test Methods:
ü The validation of an analytical method is the process by which it is established by laboratory studies that the performance characteristics of the method meet the requirement for the intended application.
ü Method validation confirms that the analytical procedure employed for a specific test is suitable for its intended use.
ü This implies that validity of a method can be demonstrated only though laboratory studies.
ü Methods should be validated or revalidated:
– before their introduction and routine use;
– whenever the conditions change for which the method has been validated, e.g., instrument with different characteristics; and
– wherever the method is changed and the change is outside the original scope of the method.
Strategy for Validation of Methods:
ü The validity of a specific method should be demonstrated in laboratory experiments using samples or standards that are similar to the unknown samples analyzed in the routine.
ü The preparation and execution should follow a validation protocol preferably written in a step-by-step instruction format as follows:
1. Develop a validation protocol oroperating procedure for the validation.
2. Define the application purpose and scope of the method.
3. Define the performance parameters and acceptance criteria.
4. Define validation experiments.
5. Verify relevant performance characteristics of the equipment.
6. Select quality materials, e.g., standards and reagents.
7. Perform pre-validation experiments.
8. Adjust method parameters and/oracceptance criteria, if necessary.
9. Perform full internal (and external) validation experiments.
10. Develop SOPs for executing the method routinely.
11. Define criteria for revalidation.
12. Define type and frequency of system suitability tests and/or analytical quality control (AQC) checks for the routine.
13. Document validation experiments and results in the validation report.
