title: Separation and determination of nimesulide related substances for quality control purposes by micellar electrokinetic chromatography.
abstract: A micellar electrokinetic chromatography (MEKC) method has been developed and validated for the determination of nimesulide related compounds in pharmaceutical formulations. Electrophoretic separation of six European Pharmacopoeia (EP) impurities (A-F) was performed using a fused silica capillary (L(eff.)=50 cm, L(tot.)=57 cm, 50 microm i.d.) with a background electrolyte (BGE) containing 25 mM borate buffer (pH 9.5), 30 mM sodium dodecyl sulphate and phi=3% (v/v) acetonitrile. The influence of several factors (surfactant and buffer concentration, pH, organic modifier, applied voltage, capillary temperature and injection time) was studied. The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. The calibration curves obtained for the six compounds were linear over the range 5-12 microgml(-1) (0.05-0.12%). The relative standard deviations (s(r)) of intra- and inter-day experiments were less than 5.0%. The detection limits ranged between 0.7 and 1.6 microgml(-1) depending on the impurity. The proposed method was applied successfully to the quantification of nimesulide impurities in its pharmaceutical formulation.
authors.affiliation: Department of Chemistry, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Constantinos K
authors.initials: CK
authors.lastname: Zacharis
authors.forename: Paraskevas D
authors.initials: PD
authors.lastname: Tzanavaras
authors.forename: Maria
authors.initials: M
authors.lastname: Notou
authors.forename: Anastasia
authors.initials: A
authors.lastname: Zotou
authors.forename: Demetrius G
authors.initials: DG
authors.lastname: Themelis
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis* / Q000302:isolation & purification*; D001888:Boric Acids / Q000737:chemistry; D002021:Buffers; D002138:Calibration; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation / Q000379:methods*; D004340:Drug Contamination; D004560:Electricity; D004573:Electrolytes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D004364:Pharmaceutical Preparations / Q000032:analysis; D010602:Pharmacopoeias as Topic; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013449:Sulfonamides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D013501:Surface-Active Agents / Q000737:chemistry; D013607:Tablets / Q000737:chemistry; D013696:Temperature
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001888:Boric Acids; D002021:Buffers; D004573:Electrolytes; D004364:Pharmaceutical Preparations; D013449:Sulfonamides; D013501:Surface-Active Agents; D013607:Tablets; D012967:Sodium Dodecyl Sulfate; C032688:boric acid; C012655:nimesulide