Comparison of native, alkylated and charged cyclodextrins for the chiral separation of labetalol stereoisomers by capillary electrophoresis

• Published in: Journal of Chromatography A Vol. 829; no. 1; pp. 341 - 349
• Main Authors: Le Potier, I., Tamisier-Karolak, S.L., Morin, Ph, Megel, F., Taverna, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 1998; Elsevier
• Subjects: Analysis; Biological and medical sciences; Cyclodextrins; General pharmacology; Labetalol; Medical sciences; Pharmacology. Drug treatments; Propranolol; β-Blockers; Cyclodextrins; Labetalol; Buffer composition; Propranolol; β-Blockers; Enantiomer separation; Aminoalcohol; Zone electrophoresis; Separation; Phase composition; Capillary electrophoresis; Antiarrhythmic agent; Mobile phase; Chiral selector; Cyclodextrin; Alpha blocking agent; Ultraviolet detector; Optical resolution; Enantiomer; pH; Antihypertensive agent; Benzamide derivatives; Beta blocking agent
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(98)00793-6

A capillary electrophoresis method for the enantioresolution of labetalol was developed using CDs as chiral selectors and uncoated capillaries. Various native (α-, β- and γ-CD), alkylated (hydroxy propyl-β- and γ-CD, methyl-β-CD) and anionic (sulfated-β-CD and sulfobutylether-γ-CD) cyclodextrins were tested and operational parameters such as buffer pH, concentration of CD were investigated. Propranolol was also studied as a model compound. Uncharged γ-CDs were more effective than β-CDs to separate the enantiomers of labetalol but no complete resolution of the four isomers was obtained. The use of charged cyclodextrins led to a combination of hydrophobic inclusion and ion-pairing interaction in the chiral recognition mechanism. Thus, a complete resolution of the four enantiomers of the labetalol was attained using 7.7 g/l sulfated-β-CD in a 30 m M phosphate buffer, pH 6.5.