Application of the Multivariate T2 Control Chart and the Mason–Tracy–Young Decomposition Procedure to the Study of the Consistency of Impurity Profiles of Drug Substances

A case study from the chemical and pharmaceutical industry is used to show the value of the application of the multivariate T 2 control chart and the Mason–Tracy–Young decomposition procedure to the study of the consistency of the impurity profiles of drug substances. The impurity profile of a drug substance is one of the most important quality characteristics, is almost always multivariate in nature, and is complicated by the relationships among the impurity levels. This prohibits examining each impurity by univariate statistical procedures. Several of the possible benefits of applying these multivariate statistical procedures to the manufacture of drug substances are illustrated through the presentation and discussion of the case study.