Impurity profile: Significance in Active Pharmaceutical Ingredient

Abstract

Various regulatory authorities like ICH, USFDA, Canadian Drug and Health Agency are
emphasizing on the purity requirements and the identification of impurities in Active
Pharmaceutical Ingredient’s (API’s). Qualification of the impurities is the process of acquiring
and evaluating data that establishes biological safety of an individual impurity; thus, revealing
the need and scope of impurity profiling of drugs in pharmaceutical research.
Identification of impurities is done by variety of Chromatographic and Spectroscopic
techniques, either alone or in combination with other techniques. There are different methods for
detecting and characterizing impurities with TLC, HPLC, HPTLC, AAS etc. Conventional
Liquid Chromatography, particularly, HPLC has been exploited widely in field of impurity
profiling; the wide range of detectors, and stationary phases along with its sensitivity and costeffective separation have attributed to its varied applications. Among the various Planar
Chromatographic Methods; TLC is the most commonly used separation technique, for isolation
of impurities; due to its ease of operation and low cost compared to HPLC. An advancement of
thin layer chromatography HPTLC, is a well-known technique for the impurity isolation.
Headspace GC is one of the most preferred techniques for identification of residual
solvents. The advent of hyphenated techniques has revolutionized impurity profiling, by not only
separation but structural identification of impurities as well. Among all hyphenated techniques,
the most exploited techniques, for impurity profiling of drugs are LC-MS-MS, LC-NMR, LCNMR-MS, GC-MS, and LC-MS.