Biphasic recognition chiral extraction — novel way of separating pantoprazole enantiomers

This paper presents a biphasic recognition chiral extraction system developed as a new chiral separation technology for the separation of pantoprazole enantiomers, combining a hydrophilic β -CD derivative in the aqueous phase and a hydrophobic tartaric acid in the organic phase which preferentially recognise the ( R )-enantiomer and ( S )-enantiomer, respectively. In this study, a number of factors which influence the efficiency of the extraction were investigated including types of organic solvents, β -CD and tartaric acid esters and their concentrations, pH and temperature. As a result, enantioselectivity for pantoprazole enantiomers can be improved up to 1.42 under optimised conditions; in addition, it is clear that the combined action of β -CD and tartaric acid esters leads to formation of the biphasic chiral extraction system with a stronger separation capacity than a monophasic chiral extraction system.