Cyclodextrins' effect on the enatioseparation of some PPIs and capillary electrophoresis method development for determining rabeprazole enantiomers

Over the past decades, chiral switch of the proton pump inhibitors (PPIs) has been received widespread attention in therapeutic advantages as well as pharmaceutical analysis. In present study, the influence of cyclodextrins (CDs) on the chiral separation of four common PPIs (lansoprazole, omeprazole, pantoprazole, and rabeprazole) was investigated. The results demonstrated that capillary electrophoresis (CE) with dual CDs as a chiral selector system is a possible and promising method for the enantioseparation of these PPIs. Rabeprazole, which is the most challenging and acid-labile candidate among four PPIs, was selected for further development of the technique. To optimize CE condition, the effects of capillary parameters and background electrolytes on the enantioseparation were investigated. Finally, the best chiral separation was acheived by using sulfobutyl ether-${\beta}$-CD, and ${\gamma}$-CD as dual chiral selectors. The developed CE method not only provided the effective chiral separation but also showed the good stability of rabeprazole. The proposed method was successfully validated according to the International Conference on Harmonization guideline and effectively applied to determine rabeprazole enantiomers in commercial rabeprazole tablets, with recoveries ranging from 97.17 % to 103.29 % of the label content.