Dry powder formulation with α-glycosyltransferase-treated stevia for the effective absorption of hydrophobic bioactive compounds in crude drugs

The purpose of this study was to prepare a functional dry powder capable of effectively improving the bioavailability of hydrophobic bioactive ingredients in crude drugs. A dry powder formulation from an ethanol extract of Brazilian green propolis was achieved in the presence of α-glycosyltransferase-treated stevia (Stevia-G). The resulting powder dispersed easily into an aqueous medium, and the average particle size of the suspension was about 350 nm. Propolis is known as a mixture of more than 200 ingredients; therefore, the suspension contains particles of hydrophobic compounds as well as dissolved molecules of several other compounds. In the suspension, the dissolved amounts of artepillin C and drupanin, representative hydrophobic bioactive compounds in propolis, in water were dramatically improved compared to their normal solubility. When the resulting propolis/Stevia-G powder was administrated into rats, pronounced absorption enhancement of artepillin C and drupanin could be detected. Stevia-G may have the potential to yield simultaneous absorption enhancement to multiple hydrophobic ingredients in crude drugs.