Investigation of a fenofibrate-hydroxypropyl-beta-cyclodextrin system prepared by a co-grinding method

Considering the poor water solubility and the low oral bioavailability in humans, the complex formation of fenofibrate (FNB) with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in aqueous solution was studied. The effect of temperature on the complexation was examined and thermodynamic parameters of the complexation process such as Gibbs free energy change (deltaG), enthalpy change (deltaH) and entropy (deltaS) change were also determined. Meanwhile, the solid dispersion of FNB with HP-beta-CD was prepared and characterized by X-ray diffractometry and Fourier IR spectroscopy. The experimental results indicated that a 1:1 molar ratio complex of FNB with HP-beta-CD could form in aqueous solution and the complexation was exothermic and enthalpy-driven process. The FNB-HP-beta-CD solid dispersion presented a remarkable improvement in the solubility and dissolution rate of the drug. This might be attributed to the amorphous state, the enhanced wettability and as well as the complex formation of the drug with HP-beta-CD in aqueous solution.