Preparation, characterization and molecular modelling of inclusion complex between -naphthylacetic acid with ethylenediamine--cyclodextrin

Using ethylenediamine--cyclodextrin and -naphthylacetic acid as raw material, a novel inclusion complex (en--CD@NAA) was synthesized. The inclusion complex structures and properties were analyzed by reliable spectroscopic and physicochemical techniques. The stoichiometry of the inclusion complex was 1:1 and the stability constant (K-S) value was found to be 2511M(-1) at 293K. Molecular thermodynamic parameters indicated that the spontaneous and exothermic nature of the process. The inclusion form was foreseen by Chem 3D program combined with H-1-NMR experimental data. The solubilization curves (K-1=2.05) and in-vitro dissolution data demonstrated that the en--CD@NAA inclusion complex has satisfactory water solubility.