Capillary electrophoretic enantioseparation of m-nisoldipine using two different beta-cyclodextrins.

The methods for the enantioseparation of m-nisoldipine, a new 1,4-dihydropyridine calcium ion antagonist, were developed. The elaborated methods of m-nisoldipine enantiomers separation were successfully performed using an anionic CD-sulfobutyl ether-beta-CD (SBE-beta-CD) or carboxymethyl-beta-CD as chiral selector. However, the results indicated that SBE-beta-CD was a better chiral selector for enantioseparation of the neutral m-nisoldipine. Furthermore, comparing the two SBE-beta-CDs, the derivative with a higher degree of substitution (DS) of 7.0 induced better enantioresolution than the one with low DS (4.0). In addition, possible chiral recognition mechanisms of dihydropyridines were discussed.