Shelf Life Calculator (ICH Q1E)
Estimate shelf life from long-term stability data the ICH Q1E way: test whether batches can be pooled, fit the regression and find where the 95% confidence bound meets the specification.
- ICH Q1E statistics
- ANCOVA poolability
- Extrapolation limit
- No sign-up
Four steps, or fewer
- Choose whether the attribute decreases (lower limit), increases (upper limit) or may do either (two-sided), and enter the limit.
- Paste the long-term results: time in months and one column per batch.
- Read the poolability tests, the statistical shelf life and the extrapolation limit. The proposed shelf life is the lower of the two.
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 ICH Q1E estimates shelf life
For a quantitative attribute, the shelf life is the time at which the one-sided 95% confidence limit for the mean regression line meets the acceptance criterion. Attributes that may increase or decrease use two-sided 95% limits.
Lower bound = ŷ(t) − t₀.₉₅,df × s × √[1/n + (t − x̄)² / Σ(x − x̄)²]
Shelf life = earliest t at which the bound meets the limit
Pooling batches
Analysis of covariance first tests whether the batch slopes are equal, then whether the intercepts are equal, each at a significance level of 0.25.
- Slopes and intercepts not significantly different: pool all batches into one line.
- Slopes equal, intercepts different: common slope with separate intercepts; the shelf life comes from the worst batch.
- Slopes different: each batch on its own; the shelf life is the shortest batch estimate.
Extrapolation
When the data support it and there is no significant change at accelerated conditions, the proposed shelf life can be up to twice the period covered by long-term data, but not more than 12 months beyond it. Real-time data must later confirm it.
References
- ICH Q1E Evaluation of stability data
- ICH Q1A(R2) Stability testing of new drug substances and products
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.