title: Separation of selected imidazole enantiomers using dual cyclodextrin system in micellar electrokinetic chromatography.
abstract: Cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was developed for simultaneous enantioseparation of three imidazole drugs namely tioconazole, isoconazole and fenticonazole. Three easily available and inexpensive cyclodextrins namely 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CD) and heptakis(2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) were evaluated to discriminate the six stereoisomers of the drugs. However, none of the three CDs gave a complete enantioseparation of the drugs. Effective enantioseparation of tioconazole, isoconazole and fenticonazole was achieved using a combination of 35 mM HP-γ-CD and 10 mM DM-β-CD as chiral selectors. The best separation using both HP-γ-CD and DM-β-CD (35 mM:10 mM) as chiral selectors were accomplished in background electrolyte (BGE) containing 35 mM phosphate buffer (pH 7.0), 50 mM sodium dodecyl sulfate (SDS) and 15% (v/v) acetonitrile at 27 kV and 30 °C with all peaks resolved in less than 15 min with resolutions, Rs 1.90-27.22 and peak efficiencies, N > 180 000. The developed method was linear over the concentration range of 25-200 mg l(-1) (r(2) > 0.998) and the detection limits (S/N = 3) of the three imidazole drugs were found to be 2.7-7.7 mg l(-1). The CD-MEKC method was successfully applied to the determination of the three imidazole drugs in spiked human urine sample and commercial cream formulation of tioconazole and isoconazole with good recovery (93.6-106.2%) and good RSDs ranging from 2.30-6.8%.
authors.affiliation: Separation Science and Technology Group (SepSTec), Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, UTM Johor Bahru, Johor, Malaysia. wanaini@kimia.fs.utm.my
authors.forename: Wan Aini
authors.initials: WA
authors.lastname: Wan Ibrahim
authors.forename: Siti Munirah
authors.initials: SM
authors.lastname: Abd Wahib
authors.forename: Dadan
authors.initials: D
authors.lastname: Hermawan
authors.forename: Mohd Marsin
authors.initials: MM
authors.lastname: Sanagi
authors.forename: Hassan Y
authors.initials: HY
authors.lastname: Aboul-Enein
mesh_terms: D002845:Chromatography; D019075:Electrophoresis, Capillary; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry* / Q000652:urine; D008823:Micelles; D015394:Molecular Structure; D004364:Pharmaceutical Preparations / Q000652:urine; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D007093:Imidazoles; D008823:Micelles; D004364:Pharmaceutical Preparations; D047392:beta-Cyclodextrins