Quantification of very low enantiomeric impurity of efaroxan using a dual cyclodextrin system by capillary electrophoresis.
A rapid method for the enantiomeric purity determination of efaroxan has been developed by capillary electrophoresis (CE) using a dual cyclodextrin (CD) system. The influence of the nature and the concentration of CDs on separation parameters has been studied. High resolution (R(s)=7) and peak efficiency (104,000-121,000 theoretical plates) values were obtained for efaroxan enantiomers by adding two cyclodextrins, one neutral (7.5 mM DM-beta-CD) and the other negatively charged (3 mM CM-beta-CD) to the running buffer composed of 100 mM phosphoric acid-triethanolamine (pH 3). These resolution and peak efficiencies values allowed the quantitation of the (S)-enantiomer of efaroxan at very low enantiomeric excess even if the minor component migrates after the major one. This method was fully validated for the enantiomeric impurity determination of the (S)-form of efaroxan at the 0.05% level. Calibration curve, expressed by the peak areas ratio versus the enantiomeric purity was linear over the 0.05-1% enantiomeric impurity range (r2=0.9996). Limits of detection (LOD) and quantification (LOQ), expressed in term of (S)-enantiomer impurity were 0.02% and 0.05%, respectively. The accuracy of the method at 0.12%, 0.50% and 0.80% enantiomeric impurity levels for the (S)-form were determined. Recoveries were in 94-102% range for each quality control sample and were determined with good precision (intra-day R.S.D.=3.54%, inter-day R.S.D.=5.33%).
Lorin
Marie
M
Institut de Chimie Organique et Analytique, CNRS FR 2708, UMR 6005, Université d'Orléans, BP 6759, Orléans 45067 Cedex 2, France.
Delépée
Raphaël
R
Morin
Philippe
P
Ribet
Jean-Paul
JP
D000838:Anions / Q000737:chemistry; D001572:Benzofurans / Q000032:analysis* / Q000737:chemistry*; D002021:Buffers; D003505:Cyclodextrins / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D007093:Imidazoles / Q000032:analysis* / Q000737:chemistry*; D015394:Molecular Structure; D012680:Sensitivity and Specificity; D013237:Stereoisomerism
D000838:Anions; D001572:Benzofurans; D002021:Buffers; D003505:Cyclodextrins; D007093:Imidazoles; C062597:efaroxan