Qualify and Quantify Free Radical Impurities

Commonly encountered factors, such as heat, light, oxygen and moisture can accelerate the degradation of a range of products. The chemical reactions involved result in the release of damaging free radicals. In addition, sterilization processes can be associated with free radical production. The detection and identification of the resultant free-radicals is thus important to determine the stability and shelf-life of a product and to ensure product quality. This is critical in the case of pharmaceuticals where the presence of degradation products will not only affect stability and efficacy, but may also compromise patient safety.

Electron paramagnetic resonance (EPR) is the only technique that can qualify and quantify the presence of free radical impurities. EPR is a versatile, non-destructive analytical technique that can detect unpaired electrons in solids, liquids, gases, cell suspensions, and in vivo. Data detailing the amount and identity of free radical species present can be acquired by EPR in a matter of seconds. EPR thus provides a valuable tool for detecting and evaluating degradation and for determining shelf-life in stress tests. 

Bruker is the world's leading supplier of EPR systems. The latest addition to the comprehensive range of EPR solutions is the EMXnano™, a high-end, compact, and affordable bench-top EPR spectrometer.