Forced Degradation Calculator
Check each stress condition for % degradation and mass balance, and see which conditions are under- or over-stressed.
- ICH Q1A and Q1B
- Mass balance
- Degradation target
- No sign-up
Four steps, or fewer
- Enter the assay and total impurities of the unstressed sample.
- Add each stress condition with its assay and total impurities.
- Adjust conditions that fall outside the degradation target and investigate poor mass balance.
Not sure what to enter? Press Load example to see the calculator with realistic data. Your inputs are saved in this browser, so they are still there when you come back.
How degradation and mass balance are calculated
Mass balance (%) = (assay + total impurities) / (A₀ + I₀) × 100
Stress testing shows the method is stability-indicating. Aim for meaningful but not excessive degradation, often 5–20%, so that primary degradants form without secondary ones. A mass balance close to 100% shows the degradants are detected; a low value can point to non-chromophoric products, volatiles or different response factors.
References
- ICH Q1A(R2) Stability testing of new drug substances and products
- ICH Q1B Photostability testing
- ICH Q2(R2) Validation of analytical procedures
These calculators are decision support for orientation and training. They are not validated GMP software, and results must be checked against your approved method, SOP and the current pharmacopoeia or guideline before use in GMP records. Your data is processed in your browser and is not sent to Molgenium.