Comparison of bracketing and matrixing designs for a two-year stability study

In the U.S. Food and Drug Administration (FDA) guidelines for stability testing of new drug products, both bracketing and matrixing designs were suggested as the statistical designs. More recently, they have increasing attention from pharmaceutical companies, because both designs reduce the cost of stability studies. The purpose of this paper is to investigate both designs in terms of the power of detection of significant difference between slopes, and use the mean square error to evaluate the precision of estimated drug shelf life. Additionally, the distributions of both designs are compared by using 1000 simulations.