Evaluating the performance of the ICH guidelines for shelf life estimation.

The goal of shelf life estimation is to determine the storage time during which the entire product meets specification with acceptably high probability. The estimated shelf life should be "applicable to all future batches" (ICH Q1E, International Conference on Harmonization, 2003b). There is compelling evidence of issues with the International Conference on Harmonization (ICH) guidelines for shelf life estimation. Issues include fixed batch effects, poolability tests, and confidence intervals for the mean. Two conclusions from evaluating the ICH procedure are that batch effects should be random and that focus should be on a quantile. A procedure is needed that combines random batches with the ICH objective of estimating the minimum batch shelf life.