Evaluation of stability data – An overview

Abstract

The guidance on the evaluation and statistical analysis of stability data provided in the parent guideline is brief in nature and limited in scope. The parent guideline states that regression analysis is an appropriate approach to analyzing quantitative stability data for retest period or shelf life estimation and recommends that a statistical test for batch poolability be performed using a level of significance of 0.25. However, the parent guideline includes few details and does not cover situations where multiple factors are involved in a full- or reduced-design study. This review is intended to provide recommendations on how to use stability data generated in accordance with the principles detailed in the ICH guideline “Q1A(R) Stability Testing of New Drug Substances and Products” (hereafter referred to as the parent guideline) to propose a retest period or shelf life in a registration application. This guideline describes when and how extrapolation can be considered when proposing a retest period for a drug substance or a shelf life for a drug product that extends beyond the period covered by “available data from the stability study under the long-term storage condition” (hereafter referred to as long-term data). The scope of the guide- line addresses the evaluation of stability data that should be submitted in registration applications for new molecular entities and associated drug products. The guideline provides recommendations on establishing retest periods and shelf lives for drug substances and drug products intended for storage at or below “room temperature”. It covers stability studies using single- or multifactor designs and full or reduced designs.