Introduction

Stress testing has long been recognized as an important part of the drug development process. Recent efforts by the International Conference on Harmonization (ICH) with regard to impurities (1-4) and stability (5-7) have brought an increased regulatory scrutiny of impurities, requiring identification and toxicological qualification at very low levels. Coupled with efforts by the pharmaceutical industry to reduce the time and cost that it takes to get products to market, the potential for stability and impurity ‘‘surprises’’ that affect the development timeline has increased dramatically. Efforts to improve and streamline processes related to early identification of potential impurity problems are important to the goal of providing new, safe medicines, faster (8).