title: [Estimation of impurity profiles of drugs and related materials. 20. Methodological problems in the identification and determination of organic impurities].
abstract: After a brief survey of some fundamental questions related to the impurity profiling of drugs a scheme is presented for the rational estimation of the impurity profile of related organic impurities in drugs and drug products. In the course of the discussion of this scheme at first the methodological questions of the detection of the impurities are summarized followed by the description of their attempted identification with known potential impurities by means of chromatographic retention matching. A complex chromatographic (electrophoretic)--spectroscopic system is then described for the identification (structure elucidation) of those impurities which could not be identified by chromatographic retention matching. The first step of this is to draw conclusions from the UV spectra easily obtainable by the HPLC/diode array UV or TLC/reflection UV spectra. This is followed by the application of various on-line and off-line possibilities of mass spectrometry with special respect to the most up-to-date HPLC/MS/(MS) technique and concluded by the use of the ultimate and most informative techniques of NMR spectroscopy. Finally the necessity of the synthesis of the identified impurities (impurity standard) is briefly mentioned followed by the discussion of the necessity and possibilities of the selective determination of the identified impurities based on the impurity standards.
authors.affiliation: Richter Gedeon Vegyészeti Gyár Rt, Budapest, Gyömrói u. 21, 1103.
authors.forename: S
authors.initials: S
authors.lastname: Görög
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004340:Drug Contamination; D004586:Electrophoresis; D013058:Mass Spectrometry; D009930:Organic Chemicals / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000592:standards*; D013053:Spectrophotometry
chemical_list: D009930:Organic Chemicals; D004364:Pharmaceutical Preparations