In the pharmaceutical world, impurity profiling of an APIs or drug substance and products is an important aspect.
It has become an important phase as per various regulatory authorities, to be carried out for all the APIs, may be because
of direct relation with the efficacy and safety of drugs. For the characterization of impurities, a number of analytical
techniques such as chromatographic, spectroscopic and sophisticated hyphenated techniques have been used. Thus, in the
present review applications of various analytical tools such as thin layer chromatography, HPTLC, HPLC, UPLC, gas
chromatography, flash chromatography, supercritical fluid chromatography, capillary electrophoresis, micellar electrokinetic
chromatography, UV-spectroscopy, IR-spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry,
liquid chromatography-mass spectrometry, liquid chromatography-mass spectrometry-mass spectrometry, liquid chromatography-
nuclear magnetic spectroscopy, high performance liquid chromatography-diode array detector- mass spectrometry,
high performance liquid chromatography-diode array detector- nuclear magnetic spectroscopy-mass spectrometry, ultra
performance liquid chromatography-mass spectrometry, ultra performance liquid chromatography-mass spectrometrymass
spectrometry, chemometrics in impurity profiling of APIs or drug products have been briefly discussed.