Abstract: Dihydromyricetin-loaded solid self-emulsifying delivery system was prepared by the silica particle adsorption method to overcome the problem of the low stability, solubility and bioavailability of dihydromyricetin. When the mass ratio of silica particles to liquid self-emulsifying delivery system was larger than 0.6, a white loose powder was prepared, which had good flowability. The content of dihydromyricetin in the solid self-emulsifying delivery system was (0.30 ± 0.03)%. The X-ray diffraction and infrared spectral results revealed that dihydromyricetin existed in an amorphous or dissolved state in the sample, and that liquid self-emulsifying delivery system was physically adsorbed into the pores of silica. The in vitro release results showed that compared with an ethanol solution of dihydromyricetin, the release time of dihydromyricetin from the liquid and solid self-emulsifying delivery system was prolonged, and the sustained release lasted for more than 8 h. Silica particles inhibited the release of dihydromyricetin to a certain extent. The in vitro simulated digestion experiments showed that the solid self-emulsifying delivery system was mainly digested in the intestinal juice. After self-emulsification, the bioaccessibility of dihydromyricetin increased from about 34.01% to more than 70%, indicating that the self-emulsifying delivery system can improve the intestinal absorption and utilization of bioactive components. Since the liquid self-emulsifying delivery system could not be dissolved or released from the pores of silica particles in time, the bioaccessibility of dihydromyricetin decreased to a certain extent after the liquid self-emulsifying delivery system was solidified. The solidification of silica particles could prolong the digestion and absorption of dihydromyricetin. Moreover, the solid self-emulsifying delivery system could improve the chemical stability of dihydromyricetin.

Key words: dihydromyricetin; solid self-emulsifying delivery system; in vitro release; simulated digestion