Simultaneous Chiral Separation of Geometry Isomers and Enantiomers of Nateglinide by Capillary Electrophoresis with Mixture of CD Derivations as Chiral Selector

A capillary electrophoresis (CE) method for the simultaneous separation of geometry isomers and enantiomers of nateglinide was built. Several different dyclodextrin (CD) derivatives were tested for the chiral separation of nateglinide, and it was proved that ionic CDs [i.e., carboxymethy--CD (CM--CD) and sulphonic--CD (S--CD)] could show better chiral selectivity for both geometry isomers and enantiomers than the neutral CDs. The separation of geometry of both isomers and enantiomers of nateglinide was obtained by CE in a 75-m i.d.60cm (effective length 45cm) fused-silica capillary at 11kV voltage, while 30mM phosphate (pH=8.38) acted as running buffer and a mixture of 40mM S--CD+21mM CM--CD served as chiral selector. The detective wavelength was set at 254nm.