Preparation of Four Types of Coenzyme Q10/γ-Cyclodextrin Supramolecular Complexes and Comparison of Their Pharmaceutical Properties

In this study, we prepared four kinds of complexes or Coenzyme Q10 (CoQ10) with gamma-cyclodextrin (gamma-CyD) by the kneading methods and the solubility methods with or without heating, and compared their pharmaceutical properties. Differential scanning calorimetrical curves and powder X-ray diffraction patterns showed that the complexes formed pseudorotaxane-like supramolecular structure, although included free gamma-CyD and CoQ10, when prepared by the kneading method and solubility method without heating. At the preparation process, a heating improved the complexation of CoQ10 with gamma-CyD in the both methods. The dispersion rate of CoQ10 in water increased in the order of CoQ10 alone approximate to physical mixture with gamma-CyD << solubility/heating product<solubility product<kneading/heating product<kneading product, possibly due to submicron-ordered particle formulation. Of the various ointments containing CoQ10 alone, the release of CoQ10 from hydrophilic ointment was fastest. In addition, the release rate of CoQ10 from hydrophilic ointment in the solubility/heating product was markedly increased, compared to that in the CoQ10/gamma-CyD physical mixture and the other complexes. The fast release of CoQ10 from hydrophilic ointment could be involved in propylene glycol in the ointment. These results suggest that supramolecular complexes of CoQ10 with gamma-CyD can be prepared by various methods, and among various complexes the pseudorotaxane-like CoQ10/gamma-CyD complexes prepared by the solubility method with heating have the potential for preparation of ointments.