title: Simultaneous determination of clopidogrel and its carboxylic acid metabolite by capillary electrophoresis.
abstract: A capillary electrophoresis method was developed and validated for the first time for the analysis of clopidogrel and its carboxylic acid metabolite. Prior to method optimization, the pH dependence of effective mobility of both compounds was determined in order to define the initial pH of the running buffer. The optimized method demonstrated to be selective, and linear in the concentration range of 2-100 microM for both compounds. The method limits of detection and quantification were, respectively, 1.2 and 3.7 microM for clopidogrel and 1.1 and 3.2 microM for the carboxylic acid metabolite. Moreover, method validation demonstrated acceptable results for method repeatability (RSD<7%), intermediate precision (RSD<7%) and accuracy (85-96%) and is suitable for the quantitative analysis of clopidogrel and its metabolite in serum samples. The validated method was also applied to the determination of the kinetic parameters of the enzymatic hydrolysis of clopidogrel. An apparent K(m) of 145+/-30 microM and V(max) of 0.4, 1.5 and 3.4 microM/min, respectively for the enzyme concentrations 1.0, 2.0 and 4.0 U/ml, were obtained.
authors.affiliation: IBET/ITQB-UNL, Av. da República-EAN, 2780-157 Oeiras, Portugal.
authors.forename: Hugo
authors.initials: H
authors.lastname: Serra
authors.forename: Maria do Rosário
authors.initials: Mdo R
authors.lastname: Bronze
authors.forename: Ana Luísa
authors.initials: AL
authors.lastname: Simplício
mesh_terms: D002264:Carboxylic Acids / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D000077144:Clopidogrel; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D016018:Least-Squares Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate; D013696:Temperature; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000378:metabolism
chemical_list: D002264:Carboxylic Acids; D012967:Sodium Dodecyl Sulfate; D000077144:Clopidogrel; D013988:Ticlopidine