ABSTRACT
I. Introduction.......................................................................................... 391
II. Designs of Stability Study................................................................... 392
III. Methods for Shelf-Life Determination................................................ 396
A. ANCOVA Modeling of Simple Stability Studies ........................ 396
B. ANCOVA Modeling of Stability Studies Designed with
Multiple Factors ............................................................................ 403
IV. Alternative Approaches for Shelf-Life Determination ....................... 416
Acknowledgments ........................................................................................... 417
References........................................................................................................ 417
The stability of a drug substance or drug product is the capacity of that substance
or product to remain within the established acceptance criteria to ensure its
identity, strength, quality, and purity within a specified period of time.
Regulatory agencies require that adequate testing be performed by an applicant
to demonstrate the stability of the drug substance or product in support of the
approval for a marketing registration application. The purpose of stability testing
is to provide evidence on how the quality of a drug substance or product varies
with time under the influence of a variety of environmental factors, such as
temperature, humidity, and light. This assessment is used to establish the
recommended storage conditions and a retest period for the drug substance or
a shelf-life for the drug product.
