Enhancement of diosgenin distribution in the skin by cyclodextrin complexation following oral administration.

Orally administrated diosgenin, a steroidal saponin found in several plants including Dioscorea villosa, recovers skin thickness reduced in ovariectomized mice, and plays an important role in the treatment of hyperlipidemia. Thus, diosgenin is an active element of cosmeceutical and dietary supplements. However, we have already elucidated that the skin distribution and absolute oral bioavailability of diosgenin is very low. The aim of this study is to evaluate the efficacy of diosgenin-cyclodextrin (CD) complexes in improving the skin concentration of diosgenin. The formation of the CD complex was indicated by powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscope (SEM) studies. Oral administration of the diosgenin/β-CD complex resulted in a significant enhancement in terms of the skin distribution of diosgenin, maximum plasma level (C(max)), area under the plasma concentration-time curve (AUC), and absolute oral bioavailability over those of the drug alone. These results suggest that the inclusion complex of diosgenin/β-CD can be used to improve low skin content of diosgenin.