Recent approaches for impurity profiling of pharmaceuticals

Abstract

Impurities must be monitored carefully to assure the quality of drugs. It is important to identify potential sources of such impurities. Selective analytical methods need to be developed to monitor them. Methodology aspects for impurity investigations are discussed along with an emphasis on understanding the origin and fate of impurities to guide decisions on process controls and specifications. Orthogonal analytical approaches for impurity investigations to provide a complete understanding of a drug substance impurity profile. Considerations for control of toxic impurities include sensitive and selective analytical methodology and determination of the process capability for removing the impurity. New impurities may be observed as changes are made in the synthesis, formulation, or production procedures, albeit for improving them. At times it is necessary to isolate and characterize an impurity when hyphenated methods do not yield the structure or when confirmation is necessary with an authentic material.