Complexation of khellin with different cyclodextrins

ABSTRACT

Inclusion complexation of khellin and beta cyclodextrin [beta CD], gamma cyclodextrin [gamma CD] and hydroxypropyl beta cyclodextrin [HP beta CD] in water and in solid state were studied by the solubility method, UV spectrophotometry, differential scanning calorimetry [DSC], X-ray diffractometry, IR-spectroscopy and dissolution study. Solubility of khellin in water increased with the addition of cyclodextrins. The complex system formed had 1 1 stoichiometric ratio with beta, gamma and HP beta CD. The apparent 1 1 stability constant of khellin complexes with beta, gamma and HPBCD were 27.71 M-1, 66.67 M-1, 32.46 M-1 respectively. Phase solubility studies revealed 14, 24 and 35 fold increase in the solubility of khellin in the presence of cyclodextrins. More evidence of complex formation was obtained from the analysis of UV, IR, DSC and X-ray diffraction studies. The dissolution rate of khellin was significantly enhanced by complexation with cyclodextrins