title: Reverse migration order of sibutramine enantiomers as a function of cyclodextrin concentration in capillary electrophoresis.
abstract: The current study demonstrates the reversal of enantiomer migration order (EMO) in capillary electrophoresis (CE) based separations of sibutramines (SIB) as a function of the concentration of two types of cyclodextrin (CD), native β-CD and acetyl-β-CD. At normal working concentrations (<10mM) of either CD, (S)-SIB migrated first. However, at CD concentrations greater than 10mM, (R)-SIB was the first to migrate. This study describes factors involved in determining EMO for sibutramine enantiomers at low and high concentrations of CDs. The reversal of EMO could be explained in terms of the opposing effects of the stability and the limiting complex mobility of the SIB-CD complexes. The enantioseparation of SIB with methyl- and 2-hydroxypropyl-β-CD was possible based on differences in the binding constants of complexes. However, reverse EMO was not observed because of equal mobilities of SIB enantiomers complexed with methyl- and 2-hydroxypropyl-β-CD.
authors.affiliation: College of Pharmacy, Chungnam National University, Daejeon 305-764, Republic of Korea.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhu
authors.forename: Enqi
authors.initials: E
authors.lastname: Wu
authors.forename: Jianbo
authors.initials: J
authors.lastname: Chen
authors.forename: Yu-Seon
authors.initials: YS
authors.lastname: Jang
authors.forename: Wonku
authors.initials: W
authors.lastname: Kang
authors.forename: Jung Kap
authors.initials: JK
authors.lastname: Choi
authors.forename: Wonjae
authors.initials: W
authors.lastname: Lee
authors.forename: Jong Seong
authors.initials: JS
authors.lastname: Kang
mesh_terms: D000215:Acylation; D002021:Buffers; D002626:Chemistry, Pharmaceutical; D003503:Cyclobutanes / Q000737:chemistry / Q000302:isolation & purification*; D004355:Drug Stability; D019075:Electrophoresis, Capillary / Q000379:methods*; D015394:Molecular Structure; D013237:Stereoisomerism; D047392:beta-Cyclodextrins / Q000032:analysis* / Q000737:chemistry
chemical_list: D002021:Buffers; D003503:Cyclobutanes; D047392:beta-Cyclodextrins; C058254:sibutramine