Preparation and characterization of inclusion complexes of pefloxacin mesylate with three kinds of cyclodextrins

The ability of α-cyclodextrin, β-cyclodextrin and hydroxypropyl-β-cyclodextrin (α-CD, β-CD and HP-β-CD) to break pefloxacin mesylate (PM) aggregates by forming inclusion complexes has been studied using 1H NMR (nuclear magnetic resonance spectroscopy), 13C NMR and fluorescence spectra. The inclusion constants are determined to compare the corresponding inclusion capacity. Solid-inclusion complexes of PM with CDs are synthesized by coprecipitation method, and all the inclusion ratios are found to be 1:1. Additionally, spatial characterization of complexes has been proposed based on two-dimensional nuclear magnetic resonance technique (2D NMR) and spatial conformation is also investigated to propose two possible models between PM and CDs.