ABSTRACT
The goal of this entry is to review and discuss the current state of affairs in pharmaceutical development with respect to the trace-level analysis of impurities in drug substances and products. It includes a discussion on the scope of the impurities issue and the regulatory considerations involved, followed by a survey and discussion of the analytical/ instrumental techniques now in routine use for the identification of trace-level impurities, with emphasis on mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. It also presents a an MS-based systematic approach to the identification of trace-level organic impurities.
