ENANTIOSEPARATION OF UNCHARGED COMPOUNDS BY CAPILLARY-ELECTROPHORESISUSING MIXTURES OF ANIONIC AND NEUTRAL BETA-CYCLODEXTRIN DERIVATIVES

The use of the polyanionic sulfobutyl-beta-cyclodextrin in combination with a neutral cyclodextrin derivative such as trimethyl-beta-cyclode xtrin (TMCD) or dimethyl-beta-cyclodextrin (DMCD) in a pH 3 phosphoric acid-triethanolamine buffer has proved to be very suited to the enant ioseparation of acidic compounds such as non-steroidal anti-inflammato ry drugs. In this paper, the usefulness of such dual cyclodextrin syst ems was evaluated for the enantioseparation of weakly acidic and neutr al compounds. Fairly good results with respect to chiral resolution we re obtained at pH 3 for weak acids in these dual systems, However, no complete enantioseparation could be achieved under these conditions fo r the neutral drug chlormezanone. Another ionizable derivative, carbox ymethyl-beta-cyclodextrin, was then investigated together with TMCD or DMCD at pH 3 and 5. After optimisation of the concentration of the ne utral cyclodextrin derivative, high enantioresolution could be obtaine d at pH 5 for chlormezanone as well as for all the other compounds tes ted. (C) 1998 Elsevier Science B.V. All rights reserved.