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RegXpertPRO
  • Home
  • Impurity QuickCheck
  • f2 Select Web
  • Pocket f2 Select
  • Max RSD Calculator
  • About
  • Contact
  • Privacy Policy
  • Terms & Conditions
  • Cancellation & Refund

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RegXpertPRO Impurity Threshold QuickCheck

Convert maximum Daily Dose into ICH-based impurity action thresholds

A limited free preview for analytical, regulatory CMC and quality teams who need quick threshold checks based on ICH Q3A(R2) and Q3B(R2).

Impurity thresholds are not just default numbers.


The Maximum Daily Dose (MDD) can change the reporting, identification and qualification threshold. 


The applicable threshold depends on whether the percentage threshold or the Total Daily Intake (TDI) threshold is lower.


That is where interpretation errors creep in.


The RegXpertPRO Impurity Threshold QuickCheck helps convert MDD into practical, ICH-based action thresholds for early assessment, review discussions and internal checks.

How to use Impurity Threshold QuickCheck

Enter the MDD value in mg/day and select the applicable ICH pathway: 

ICH Q3A(R2) - New Drug Substance impurities

ICH Q3B(R2) - Degradation products in new Drug Products


The QuickCheck generates:

  • Reporting threshold
  • Identification threshold
  • Qualificaiton threshold
  • TDI-to-% conversion when applicable
  • Pathway-specific threshold interpretation 
  • Printable report

Launch Impurity threshold QuickCheck

Useful for:

  • Impurity threshold checks during development
  • Stability impurity review
  • Specification discussions
  • Regulatory CMC review
  • Internal technical discussions

Important Note

This tool provides threshold logic based on the entered MDD (mg/day) and the selected pathway - ICH Q3A(R2) or ICH Q3B(R2).


It does not replace product-specific impurity justification, toxicological assessment, clinical qualification, analytical capability assessment, or specification setting strategy.


Thresholds are action boundaries. They should not be automatically copied as final specification limits.

Limited free preview

This QuickCheck is currently available as a limited free preview as RegXpertPRO builds the next layer of impurity decision support beyond threshold lookup. 

Help shape the next impurity decision tool

This QuickCheck is the first layer. 


The next version can go beyond threshold lookup into impurity interpretation, comparison and justification support.


What would make the next version more useful in your impurity review and justification?

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