Enantioseparation of phenothiazines in CD‐modified CZE using single isomer sulfated CD as a chiral selector

Abstract

Enantioseparations of five chiral phenothiazines in CD-modified CZE using the single isomer sulfate-substituted beta-CD (heptakis(2,3-dihydroxy-6-O-sulfo)-beta-CD, SI-S-beta-CD) and dual CD systems consisting of SI-S-beta-CD and a neutral CD as chiral selectors in a citrate buffer at pH 3.0 were investigated. The results indicate that SI-S-beta-CD is an excellent chiral selector for enantioseparation of promethazine. The enantiomers of trimeprazine were well separated, while those of ethopropazine could also be baseline-resolved with SI-S-beta-CD. With dual CD systems, especially with hydroxypropyl-beta-CD (HP-beta-CD) as neutral CD, the enantioselectivity of thioridazine and ethopropazine was considerably enhanced. Effective enantioseparation of phenothiazines, except for methotrimeprazine, could thus be favorably and simultaneously achieved. Moreover, reversal of the enantiomer migration order of ethopropazine and thioridazine occurred by varying the concentration of gamma-CD in the presence of SI-S-beta-CD. These phenomena may be attributable to the opposite effects of sulfated beta-CD and gamma-CD on the mobility of the enantiomers of ethopropazine and of thioridazine. Comparative studies on the enantioseparations of phenothiazines with single CD and dual CD systems containing SI-S-beta-CD and randomly sulfate-substituted beta-CD (MI-S-beta-CD) were made.

Characterizing the interaction between enantiomers of eight psychoactive drugs and highly sulfated‐β‐cyclodextrin by counter‐current capillary electrophoresis

“…, except for terfenadine, baseline resolution was achieved for all the analytes studied and high Rs values were obtained. The Rs values obtained were similar to or higher than those reported in the literature for these compounds with other cyclodextrins, but obtained in most cases using higher CD concentrations than here (Castro‐Puyana et al ., ; Van Eeckhaut et al ., ; Matsunaga et al ., ; Inoue and Chang, ; Rudaz et al ., ; Bonato et al ., ; Perrin et al ., ; Li and Vigh, ; Asensi‐Bernardi et al ., ; Yang et al ., ; Liao et al ., ; Chen et al ., ; Wei et al ., ).…”

Chiral Separations by Capillary Electrophoresis

“…Recent applications using single-isomeric CD have been reported [53,54]. In [53], a method was developed for the enantiomeric impurity determination of linezolid.…”

“…Heptakis(2,3-dihydroxy-6-sulfato)-β-CD was used as a chiral selector to investigate the enantioseparation of five phenothiazines within one run [54]. Additionally, dual CD systems, where this selector or a mixture of S-β-CD isomers is combined with neutral CDs, such as HP-β-CD, β-CD, and γ-CD, were also investigated.…”

“…In tablets containing racemic citalopram, 0.07% and 0.03% (S)-and (R)-citadiol were found, respectively. Other recent applications using dual CD systems were discussed above [35,54].…”

Use of Sulfated Cyclofructan 6 and Sulfated Cyclodextrins for the Chiral Separation of Four Basic Pharmaceuticals by Capillary Electrophoresis

“…α‐, β‐, γ‐Cyclodextrins (α‐, β‐, γ‐CDs) and their derivatives are the most frequently used chiral selectors in CE . The mechanism is based mainly on the inclusion or incorporation of analytes, or at least a part of the analytes, in a hydrophobic basket of the various CDs .…”