title: Characterization of stress degradation products of benazepril by using sophisticated hyphenated techniques.
abstract: Benazepril, an anti-hypertensive drug, was subjected to forced degradation studies. The drug was unstable under hydrolytic conditions, yielding benazeprilat, which is a known major degradation product (DP) and an active metabolite. It also underwent photochemical degradation in acid and neutral pH conditions, resulting in multiple minor DPs. The products were separated on a reversed phase (C18) column in a gradient mode, and subjected to LC-MS and LC-NMR studies. Initially, comprehensive mass fragmentation pathway of the drug was established through support of high resolution mass spectrometric (HR-MS) and multi stage tandem mass spectrometric (MS(n)) data. The DPs were also subjected to LC-MS/TOF studies to obtain their accurate masses. Along with, on-line H/D exchange data were obtained to ascertain the number of exchangeable hydrogens in each molecule. LC-(1)H NMR and LC-2DNMR data were additionally acquired in a fraction loop mode. The whole information was successfully employed for the characterization of all the DPs. A complete degradation pathway of the drug was also established.
authors.affiliation: Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, 160062 Punjab, India.
authors.forename: Mallikarjun
authors.initials: M
authors.lastname: Narayanam
authors.forename: Archana
authors.initials: A
authors.lastname: Sahu
authors.forename: Saranjit
authors.initials: S
authors.lastname: Singh
mesh_terms: D001552:Benzazepines / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D002853:Chromatography, Liquid / Q000379:methods*; D041961:Deuterium Exchange Measurement; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000379:methods*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D055668:Photochemical Processes
chemical_list: D001552:Benzazepines; C044946:benazepril