Electrophoretic separation of multiple chiral center analyte with a three cyclodextrins mixture.

Abstract

A capillary electrokinetic chromatography method (CEKC) was developed for complete stereoisomeric separation of a neutral, hydrophobic, multiple chiral center dihydropyridone analogue, a drug candidate proposed in type 2 diabetes treatment. A background electrolyte comprising three cyclodextrins was found to successfully separate the eight isomers. First an anionic cyclodextrin, the SBE-β-CD, was selected to allow the chiral separation of our neutral compound and partial resolutions of the eight isomers were obtained. Then, the effects of different parameters such as the nature and concentration of the other cyclodextrins added and pH of the buffer were examined. Finally, a triple CD-system consisted of 15 mMSBE-β-CD plus 15 mMγ-CD and 40 mMHP-γ-CD in a 50mM borate background electrolyte at pH 10, was found to successfully separate the eight isomers. Last, the selectivity and limits of detection and quantification were evaluated for this optimized method.