Stability Analysis with Fixed Batches
In Chapters 11 and 12 we consider only the estimation of drug shelf life for a single active ingredient of a drug product. In addition, we assume that the strength of the drug product decreases linearly with time. Furthermore, as indicated in the FDA guideline, the percent of label claim on the original scale, not percent of initial value, is used as the primary variable for determination of shelf life of the drug product. In this chapter we focus on statistical analysis for estimation of drug shelf life with fixed batch effects. The case where batch effects are assumed random is discussed in Chapter 12.