Stability and clinical effectiveness of emulsion containing Asparagus racemosus root extract

Abstract

Asparagus racemosus root extract was entrapped in hydroxypropyl-β-cyclodextrin (HPβCD) by a physical mixing method and then incorporated in an oil in water (o/w) emulsion to evaluate its stability and clinical effectiveness. After the emulsion containing the HPβCD-entrapped extract was kept at 45.0±2.0 °C for 90 days, 90% of saponins, major compounds of the extract, remained. Without entrapment with HPβCD, the amount of saponins would have decreased to 10% after storage for 60 days. After application of the emulsion containing the entrapped extract or the unentrapped extract to the outermost layer of full thickness skin, about 38% of saponins could penetrate into the skin. A higher amount of saponins was accumulated in the outermost layer applied with emulsion containing the entrapped extract. For a clinical study, measurement of the surface evaluation of wrinkles (SEw) at the zygomatic area of the face was measured at weeks 8 and 12. The average SEw value of group of subjects that applied the extract-free emulsion was significantly higher than that of the group that applied the emulsion containing the entrapped extract (p < 0.05). Our study indicates that in o/w emulsion, saponins in A. racemosus root extract could maintain their stability after entrapping the extract within HPβCD. Moreover, the effectiveness of the entrapped extract on prevention of wrinkle progression was seen.