Impurity Limits quickcheck
Check whether proposed impurity limits are aligned with ICH Q3A/Q3B thresholds
A practical decision - support QuickCheck for analytical, regulatory CMC and quality teams reviewing proposed impurity limits during development, stability review, specification setting or regulatory response preparation.
Impurity limits should not be copied from the ICH threshold tables without context.
The applicable threshold depends on the selected pathway (ICH Q3A or ICH Q3B), maximum daily dose and whether the proposed limit relates to a specified identified impurity, specified unidentified impurity or unspecified impurity.
This Impurity Limit QuickCheck helps map MDD to applicable ICH-based thresholds and compares the proposed limits against the relevant threshold boundary.
What you enter
- Maximum daily dose
- ICH pathway: Q3A or Q3B
- Impurity category
- Proposed impurity limit
What the QuickCheck generates
- Reporting threshold
- Identification threshold
- Qualification threshold
- TDI-to-% conversion, where applicable
- Proposed limit suitability verdict
- Suitability rationale
- Printable review output
Output verdict
Suitable with justification
The proposed limit is aligned with the applicable ICH threshold and can be considered suitable, subject to product - specific justification, analytical capability and batch/ stability support.
Not Suitable
The proposed limit exceeds the applicable threshold or is not aligned with the selected impurity category. Additional justification, qualification, reassessment or limit revision may be required.
Useful for
- Setting impurity profiles and specifications
- Proposed impurity limit review
- Specification suitability discussions
- Stability impurity trend review
- Regulatory CMC response strategy
- Preliminary screening before toxicological or clinical qualification assessment
Important
This QuickCheck provides ICH-based limit suitability assessment using the entered MDD, selected pathway (ICH Q3A or Q3B) and proposed impurity limit.
it does not replace product - specific impurity justification, toxicological assessment, clinical qualification, analytical capability assessment, batch data review, stability trend assessment or final specification - setting strategy.
ICH Q3A/ Q3B thresholds are regulatory action boundaries. They should not be automatically copied as final specification limits.
Access
The Impurity Limits QuickCheck is currently available free as part of RegXpertPRO tool suite.