Study of Cyclodextrin/Fluoroquinolone Inclusion Complexes by Capillary Electrophoresis

Introduction: In the present work we evaluated the complexation role of cyclodextrins toward fluoroquinolones in an attempt to assess their potential as new formulation additives for more efficient fluoroquinolone delivery and as selectors in capillary electrophoresis.
Material and method: Guest-host interactions of two second generation quinolones, ciprofloxacin and norfloxacin with four cyclodextrins, beta-cyclodextrin (β-CD), gamma-cyclodextrin (γ-CD) and two beta-cyclodextrin derivatives, 2-hydroxypropyl beta-cyclodextrin (HP-β-CD) and randomly methylated beta-cyclodextrin (RAMEB), were tested by capillary electrophoresis in borate running buffer. Experimental parameters like buffer concentration, pH, organic modifier, voltage and cyclodextrin concentration have been varied for a better resolution.
Results: In capillary zone electrophoresis ciprofloxacin and norfloxacin are migrating together, a difference in their migration times and thus separation occured by the addition of cyclodextrins.
Conclusion: Our results suggest formation of inclusion complexes between fluoroquinolones and cyclodextrins. Differences in their affinity to host molecules resulted in separation of the two fluoroquinolones.