title: Liquid-chromatographic separation and determination of process-related impurities, including a regio-specific isomer of celecoxib on reversed-phase C18 column dynamically coated with hexamethyldisilazane.
abstract: A simple and rapid reversed-phase high-performance liquid-chromatographic method for the separation and determination of process-related impurities of celecoxib (CXB) in bulk drugs and pharmaceuticals was developed. The separation of impurities viz., 4-methylacetophenone (I), 1-(4-methylphenyl)-4,4,4-trifluorobutane-1,3-dione (II), 4-hydrazinobenzene sulfonamide (III) and a regio-specific isomer [3-(4-methylphenyl)-5-trifluoromethyl-1H-pyrazole-1-yl]-benzenesulfonamide (IV), was accomplished on an Inertsil ODS-3 column dynamically coated with 0.1% hexamethyldisilazane (HMDS) in acetonitrile:water (55:45 v/v) as a mobile phase and detection at 242 nm using PDA at ambient temperature. The chromatographic conditions were optimized by studying the effects of HMDS, an organic modifier, time of silanization and column temperature. The method was validated and found to be suitable not only for monitoring the synthetic reactions, but also to evaluate the quality of CXB.
authors.affiliation: HPLC/UV Group, Division of Analytical Chemistry, Discovery Laboratory, Indian Institute of Chemical Technology, Hyderabad-500007, India. rnrao@ins.iictnet.com
authors.forename: R Nageswara
authors.initials: RN
authors.lastname: Rao
authors.forename: S
authors.initials: S
authors.lastname: Meena
authors.forename: D
authors.initials: D
authors.lastname: Nagaraju
authors.forename: A Raghuram
authors.initials: AR
authors.lastname: Rao
authors.forename: S
authors.initials: S
authors.lastname: Ravikanth
mesh_terms: D000097:Acetonitriles / Q000032:analysis; D000068579:Celecoxib; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002625:Chemistry, Organic / Q000379:methods; D002845:Chromatography; D002853:Chromatography, Liquid / Q000379:methods*; D016861:Cyclooxygenase Inhibitors / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D017646:Organosilicon Compounds / Q000032:analysis*; D011720:Pyrazoles / Q000032:analysis*; D015203:Reproducibility of Results; D012821:Silanes / Q000737:chemistry; D013449:Sulfonamides / Q000032:analysis*; D013696:Temperature; D014867:Water / Q000032:analysis
chemical_list: D000097:Acetonitriles; D016861:Cyclooxygenase Inhibitors; D017646:Organosilicon Compounds; D011720:Pyrazoles; D012821:Silanes; D013449:Sulfonamides; D014867:Water; C082343:silanol; C024548:hexamethylsilazane; D000068579:Celecoxib; C032159:acetonitrile