title: Identification and characterization of a principal oxidation impurity in clopidogrel drug substance and drug product.
abstract: The focus of this study is identification, isolation and characterization of a principal oxidation impurity of clopidogrel which ranged from 0.05 to 0.12% using high performance liquid chromatography. This impurity is considered as principal oxidation impurity as it is observed in oxidative degradation (stress) study. Preparative HPLC with Xterra MS C18 ODB column was used to isolate the impurity. The isolated impurity was co-injected with the sample containing impurities and found the retention time match of the spiked impurities. A thorough study was undertaken to characterize this impurity and based on their spectral data (UV, MS, MSn 1H/13C, DEPT and 2D NMR) the structure was characterized as 5-[1-(2-chlorophenyl)-2-methoxy-2-oxoethyl]-6,7-dihydrothieno[3,2-c]pyridin-5-ium with a molecular weight 320 amu.
authors.affiliation: Torrent Research Center, C/O Torrent Pharmaceuticals Ltd., Indira Bridge, Bhat Village, Gandhi Nagar, Pin code 382428, Gujarat, India. arivozhimohan@hotmail.com
authors.forename: Arivozhi
authors.initials: A
authors.lastname: Mohan
authors.forename: M
authors.initials: M
authors.lastname: Hariharan
authors.forename: E
authors.initials: E
authors.lastname: Vikraman
authors.forename: G
authors.initials: G
authors.lastname: Subbaiah
authors.forename: B R
authors.initials: BR
authors.lastname: Venkataraman
authors.forename: D
authors.initials: D
authors.lastname: Saravanan
mesh_terms: D000077144:Clopidogrel; D004340:Drug Contamination; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D004364:Pharmaceutical Preparations / Q000032:analysis*; D010975:Platelet Aggregation Inhibitors / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry
chemical_list: D004364:Pharmaceutical Preparations; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine