Best Practices for Drug Substance Stress and Stability Studies During Early-Stage Development Part I—Conducting Drug Substance Solid Stress to Support Phase Ia Clinical Trials

Abstract

Regulatory guidances for drug stability testing during early development stages lack specifics. Consequently, companies either conduct more stability studies than necessary just to avoid regulatory questions or perform insufficient stability work resulting in regulatory questions and delays in drug development. Hence, there exist a pressing need and a great opportunity for pharmaceutical companies to share drug stability testing practices, rationales, and regulatory experiences for the early stages of development. This paper describes a quick, streamlined solid stress practice to support drug development from pre-clinical to Phase Ia Clinical Trials. By subjecting a few grams of drug substance to high temperature and high humidity (e.g., 70 °C/75 % RH, in open and closed containers, for three weeks) and to the ICH Q1B confirmatory photostability testing condition, the initial DS retest period and the initial shelf life of powder for oral solution can be reliably extrapolated, and a bulk packaging choice is made. In addition, the solid stress results can be used for multifaceted purposes. The solid stress practice offers a quick turnaround in obtaining adequate stability information for new drug development and achieves an optimum balance between risk and cost for Phase Ia clinical development.