Ongoing Analytical Procedure Performance Verification-Stage 3 of USP

For high-risk analytical procedures (see later section for how risk is determined), control-chart monitoring of selected performance data, generated during routine use of the procedure, can provide early warning of changes in performance. In such cases it may not be possible/practical to improve the procedure performance to reduce the risk of out-of-specification data, but it may be appropriate to consider manufacturing process improvements or review of the specification limit(s). The number and types of analytical procedure errors will provide information on the liability of analytical procedure. * Validity: the number of invalid test results due to failures of system suitability criteria (established during Stage 1 of the lifecycle approach) in a given time period * Measurements collected during each analytical procedure test occasion monitored using control charts: these measurements could be critical analytical procedure attributes or parameters specified in the analytical procedure with well-defined acceptance criteria or ranges, respectively, or attributes or parameters selected due to a potential link with procedure performance. A useful mechanism to identify the most value-adding performance attributes or parameters to monitor for high-risk procedures is to perform a procedure performance cause-and-effect review (PPC&ER).