title: A validated enantiospecific method for determination and purity assay of clopridogrel.
abstract: A new and accurate HPLC method using beta-cyclodextrin chemically bonded to spherical silica particles as chiral stationary phase (CSP) was developed and validated for determination of S-clopidogrel and its impurities R-enantiomer and S-acid as a hydrolytic product. The effects of acetonitrile and methanol content in the mobile phase and temperature on the resolution and retention of enantiomers were investigated. A satisfactory resolution of S-clopidogrel active form and its impurities was achieved on ChiraDex column (5 microm, 4 x 250 mm) at a flow rate of 1.0 ml/min and 17 degrees C using acetonitrile, methanol and 0.01 M potassium dihydrogen phosphate solution (15:5:80 v/v/v) as mobile phase. The detection wavelength was set at 220 nm. The method was validated in terms of accuracy, precision, linearity, and robustness. The limit of detection for R-enantiomer and S-acid were 0.75 and 0.09 microg/ml, respectively, injection volume being 20 microl. Finally, the molecular modeling of the inclusion complexes between the analytes and beta-cyclodextrin was performed to investigate the mechanism of the enantiorecognition and to study the quantitative structure-retention relationships.
authors.affiliation: Faculty of Pharmacy, Institute of Pharmaceutical Chemistry and Drug Analysis, University of Belgrade, Belgrade, Serbia. knikolic@pharmacy.bg.ac.yu
authors.forename: Katarina
authors.initials: K
authors.lastname: Nikolic
authors.forename: Branka
authors.initials: B
authors.lastname: Ivković
authors.forename: Zeljka
authors.initials: Z
authors.lastname: Besović
authors.forename: Slavko
authors.initials: S
authors.lastname: Marković
authors.forename: Danica
authors.initials: D
authors.lastname: Agbaba
mesh_terms: D001681:Biological Assay; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D000077144:Clopidogrel; D019295:Computational Biology / Q000379:methods; D004340:Drug Contamination; D017408:Guidelines as Topic; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D015394:Molecular Structure; D010975:Platelet Aggregation Inhibitors / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D012015:Reference Standards; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013607:Tablets; D013678:Technology, Pharmaceutical; D013816:Thermodynamics; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D010975:Platelet Aggregation Inhibitors; D013607:Tablets; D047392:beta-Cyclodextrins; D000077144:Clopidogrel; C031215:betadex; D013988:Ticlopidine