The definitions given below apply to the terms used in these guidelines. They may have different meanings in other contexts.
accelerated stability testing
Studies designed to increase the rate of chemical degradation and physical change of a drug by using exaggerated storage conditions as part of the formal stability testing programme. The data thus obtained, in addition to those derived from real-time stability studies, may be used to assess longer-term chemical effects under non-accelerated conditions and to evaluate the impact of short-term excursions outside the label storage conditions, as might occur during shipping. The results of accelerated testing studies are not always predictive of physical changes.
batch
A defined quantity of product processed in a single process or series of processes and therefore expected to be homogeneous. In continuous manufacture, the batch must correspond to a defined fraction of production, characterized by its intended homogeneity.
climatic zones
The four zones into which the world is divided based on the prevailing annual climatic conditions (see section 2).
expiry date
The date given on the individual container (usually on the label) of a drug product up to and including which the product is expected to remain within specifications, if stored correctly. It is established for each batch by adding the shelf-life period to the date of manufacture.
mean kinetic temperature
The single test temperature for a drug product corresponding to the effects on chemical reaction kinetics of a given temperature-time distribution. A mean kinetic temperature is calculated for each of the four world climatic zones according to the formula developed by Haynes (2). It is normally higher than the arithmetic mean temperature.
real-time (long-term) stability studies
Experiments on the physical, chemical, biological, biopharmaceutical and microbiological characteristics of a drug, during and beyond the expected shelf-life and storage periods of samples under the storage conditions expected in the intended market. The results are used to establish the shelf-life, to confirm the projected shelf-life, and to recommend storage conditions.
shelf-life
The period of time during which a drug product, if stored correctly, is expected to comply with the specification1 as determined by stability studies on a number of batches of the product. The shelf-life is used to establish the expiry date of each batch.
1 "Shelf-life specification" means the requirements to be met throughout the shelf-life of the drug product (should not be confused with ''release specification").
stability
The ability of a pharmaceutical product to retain its chemical, physical, microbiological and biopharmaceutical properties within specified limits throughout its shelf-life.
stability tests
A series of tests designed to obtain information on the stability of a pharmaceutical product in order to define its shelf-life and utilization period under specified packaging and storage conditions.
supporting stability data
Supplementary data, such as stability data on small-scale batches, related formulations, and products presented in containers other than those proposed for marketing, and scientific rationales that support the analytical procedures, the proposed retest period or the shelf-life and storage conditions.
utilization period
The period of time during which a reconstituted preparation or the finished dosage form in an opened multidose container can be used.