Saponins are an important class of surface-active substances. When formulated as an active ingredient or co-used with other drugs, the effect of their surface activity on efficacy or safety must be considered. In this paper, diammonium glycyrrhizinate (DG), a clinical hepatoprotective drug that has long been used as a biosurfactant, was taken as the research object to study its combined hepatoprotective effect with baicalin (BAI). Animal experiments proved that the preparation of DG and BAI integrated into micelles (BAI-DG Ms) had a better protective effect on acute liver injury caused by carbon tetrachloride than the direct combined use of the two. From the perspective of biopharmaceutics, the synergistic mechanism of BAI-DG Ms was further explored. The results showed that after forming BAI-DG Ms with DG, the solubility of BAI increased by 4.75 to 6.25 times, and the cumulative percentage release in the gastrointestinal tract also increased by 2.42 times. In addition, the negatively charged BAI-DG Ms were more likely to penetrate the mucus layer and be absorbed by endocytosis. These findings provide support for the rational application of glycyrrhizin, and other saponins.
Keywords: biopharmaceutics; drug-loaded micelles; glycyrrhizic acid; saponin; surface-active drug.