Investigation of deep eutectic solvents as additives to β-CD for enantiomeric separations of Zopiclone, Salbutamol, and Amlodipine by CE.

The enantioseparation of chiral drugs via CE was first investigated using β-CD as chiral additive and deep eutectic solvents (DESs) as auxiliary additive. The results showed that improved separation of tested chiral drugs was obtained in the presence of DESs and β-CD compared to the single β-CD separation system. With the optimized condition, resolutions of DESs applied β-CD separation system for rac-Zopiclone, rac-Salbutamol, and rac-Amlodipine increased 3-4.2 times as single β-CD separation system. The resolutions reached 4.74, 6.37, and 9.67, respectively. The results demonstrate that DESs are viable additives to CD system in CE for the separation of the chiral drugs.