Impurities in Pharmaceuticals- A Review.

Abstract

Impurity is defined as any substance coexisting with the original drug, such as starting material or intermediates or that is formed due to any side reactions. The impurity may be developed either during formulation, or upon aging of both API's and formulated API's in medicines. The presence of these unwanted chemicals, even in small amount, may influence the efficacy and safety of the pharmaceutical products. The control of impurities is currently a critical issue to the pharmaceutical industry. Impurity profiling includes identification, structure elucidation and quantitative determination of impurities and degradation products in bulk drug materials and pharmaceutical formulations. Identification of impurities is done by variety of Chromatographic and Spectroscopic techniques, either alone or in combination with other techniques. The advent of hyphenated techniques has revolutionized impurity profiling, by not only separation but structural identification of impurities. This review highlights the different types of impurities and various methods for isolation, separation and characterization of impurities.