Improvement of Pharmaceutical Properties of Isoprenoid Compounds through the Formation of Cyclodextrin Pseudorotaxane-Like Supramolecules

The purpose of this study was to design cyclodextrin (CyD)-based pseudorotaxane-like supramolecular complexes with various isoprenoid compounds, such as reduced coenzyme Q10 (R-CowQ10), squalene, tocotrienol, and teprenone, and to evaluate their pharmaceutical properties. Squalene, tocotrienol, and teprenone formed precipitates with beta-CyD and gamma-CyD in aqueous solution, whereas R-CoQ10 formed precipitates with gamma-CyD aqueous solution. The results of powder X-ray diffraction and H-1-NMR analyses indicated that these precipitates are derived from pseudorotaxane-like supramolecular complexes. The photostability of teprenone was markedly improved by complexation with CyDs, especially in the gamma-CyD system. In addition, the dispersion rates of teprenone in the gamma-CyD system were higher than those in the beta-CyD system, compared with the corresponding physical mixtures. In conclusion, pharmaceutical properties such as photostability and dispersion rates of isoprenoid compounds were improved by the formation of pseudorotaxane-like supra molecular complexes with beta-CyD and/or gamma-CyD.