A Review on The Impurity Profile of Pharmaceuticals

Abstract

A collection of analytical procedures known collectively as “impurity profiling” are intended to detect, identify, clarify the structure of, and quantify both organic and inorganic impurities as well as residual solvents in pharmaceutical formulations and bulk pharmaceuticals. This is the main task of contemporary drug analysis since it is the most effective approach to describe the stability and quality of pharmaceutical formulations and bulk pharmaceuticals. To keep an eye on them, specific analytical techniques must be created. When modifications are made to the synthesis, formulation, or production processes, even if they are done to improve them, new purities could be seen. The identification of impurities in Active Pharmaceutical Ingredients (APIs) and the need for purity are being emphasised by a number of regulatory bodies, including the Canadian Drug and Health Agency (CDHA), the United States Food and Drug Administration (FDA), and the International Conference on Harmonisation (ICH). Pharmaceutical products can contain impurities from a variety of sources, including reagents, heavy metals, ligands, catalysts and other materials like charcoal, filter aids, and the like. Degraded end products from hydrolysis, photolytic cleavage, oxidative degradation, decarboxylation, and other processes can also contain impurities, as can enantiomeric impurities. The various pharmacopoeias, including the Indian, American, and British pharmacopoeias, are gradually adding restrictions to the permissible concentrations of contaminants found in APIs or formulations. Capillary electrophoresis, electron paramagnetic resonance, gas-liquid chromatography, gravimetric analysis, high performance liquid chromatography, solidphase extraction techniques, liquid-liquid extraction techniques, mass spectrometry, ultraviolet spectrometry, infrared spectroscopy, supercritical fluid extraction column chromatography, nuclear magnetic resonance (NMR) spectroscopy, and RAMAN spectroscopy are some of the techniques used to isolate and characterize impurities in pharmaceuticals. Liquid Chromatography (LC)-Mass Spectroscopy (MS), GC-MS, LC-NMR, LC- NMR-MS, and LC-MS are the most frequently used hyphenated techniques for drug impurity profiling. This demonstrates the importance and range of drug impurity profiling in pharmaceutical research.