Comparative study of chiral separation of ofloxacin enantiomer by capillary electrophoresis using neutral cyclodextrins

    ZHAO Yan, YANG Xingª²Bin, LI Xiaoª²Ye, WANG Qiaoª²Feng, ZHANG Shengª²Yong

    1Department of Chemistry, School of Pharmacy, Fourth Military Medical University, Xi¬ðan 710033, China, 2 College of Life Science, Key Laboratory for Official Plant Resource and Pharmaceutical Chemistry of Ministry of Education, Shaanxi Normal University, Xi¬ðan 710062, China

    ¡¾Abstract¡¿ AIM: To compare the separation ability of different neutral cyclodextrins (CD) and their derivatives on ofloxacin enantiomer by capillary electrophoresis (CE) and to explore the possible mechanisms of chiral separation. METHODS: The effects of concentration and type of neutral CD, buffer pH, running voltage and capillary temperature on the enantioseparation were investigated by CE using ¦Áª²CD, ¦Âª²CD, ¦Ãª²CD, hydropropylª²¦Âª²CD (HPª²¦Âª²CD) and dimethylª²¦Âª²CD (DMª²¦Âª²CD) respectively. RESULTS: Under the optimized CE conditions (50 mmol/L phosphate buffer at pH=3.0, capillary temperature 25¡æ, separation voltage 15 kV using 25 mmol/L DMª²¦Âª²CD or by the combination of 50 mmol/L HPª²¦Âª²CD and 25 mmol/L ¦Ãª²CD), ofloxacin enantiomer was completely separated with resolution as high as 2.0 and 1.7 respectively. CONCLUSION: Inclusionª²complexation mechanism is based on the cavity size and function of the rim of CDs. The proposed method was simple and rapid with high separation efficiency and can be used for enantioseparation of ofloxacin drug. ......