Stability basics
Estimate shelf-life and expiry using standard stability inputs.
Summary
This calculator follows the linear regression approach described in ICH Q1E for evaluating stability data and estimating shelf-life.
Use time points and assay results to estimate a trend and identify when the product is expected to cross the acceptance limit. This calculator provides a simple point estimate and should be used alongside formal stability protocols and statistical review.
Step-by-step: Estimate shelf-life trend
- Capture timepoints and assay results
Enter matched stability timepoints and assay results.
- Set the acceptance limit
Provide the specification limit for the attribute.
- Estimate trend and shelf-life
Use linear regression (per ICH Q1E) to estimate when the trend crosses the spec limit.
Stability inputs
Enter timepoints and assay results per row.
Timepoint 1
Enter matched time and result.
Timepoint 2
Enter matched time and result.
At least two timepoints are required to fit a trend. For a meaningful assessment, use several timepoints (three or more) to align with typical stability protocols and improve slope reliability.
Trend results
y is the assay result at time t, a is the intercept (predicted result at time 0), and b is the slope (change per month).
Provide at least two timepoints with results to calculate the trend.
Regulatory references
Read-only guidance aligned with major regulatory bodies.