On stability designs in drug shelf-life estimation.

In this paper, various stability designs, including matrixing and bracketing designs for determining drug shelf-life, are considered. We propose a criterion for design selection based on the precision of drug shelf-life estimates. For a fixed sample size, it is recommended that the design with the best precision for estimating the shelf-life should be used. For a fixed desired precision, the design with the smallest sample size is the best choice of design. An example is presented to illustrate the proposed method.