Enantiomeric Separation of (R,S)-Aclidinium Bromide with Negatively Charged Gamma-Cyclodextrin by CE
Abstract
A new CE method for separation of (R,S)-aclidinium bromide enantiomers has been developed and validated. In this method, sulphated gamma-CD 4.8% (w/v) in acidic background electrolyte based on potassium dihydrogen phosphate (100 mM, pH = 3.0) buffer was used for the determination in an uncoated fused silica capillary with extended capillary light path.
The effect on the resolution of the chiral selector concentration, of the pH of the background electrolyte and also of other parameters was studied. (R)-Aclidinium bromide has therapeutic properties and, thus, a screening method is required for determination of low concentrations of (S)-aclidinium bromide as an optical impurity. The proposed method enables determination of 0.4% (S)-aclidinium bromide as an optical impurity in a synthetic laboratory sample.