Colloidal Particle in Suspensions of Maobushisaishinto Extract Granules Enhances Drug Intestinal Penetration

The main ingredients of Maobushisaishinto (MBST) are ephedrine (EP), methyl eugenol (ME), and aconitine (AC). The pharmacological effects are presumed to be due to the combined effects of these ingredients. In this study, we investigated the impact of the particles present in MBST suspensions on the absorption of the ingredients. Coarse, colloidal, and molecular dispersions were detected when MBST was dispersed in water at 25 and 70 °C. Regardless of temperature, the ratio of MBST in molecular dispersions was the highest, and the ratio of coarse dispersions was greater than that of colloidal dispersions. Particles ranging from 50 to 900 nm were observed in the colloidal dispersions prepared by treatment at 25 °C for 3 min. However, in 70 °C water, the mean particle size decreased, and the number of nanoparticles tended to increase. The levels of EP, ME, and AC in molecular dispersions were higher than those in coarse and colloidal dispersions, with no significant difference observed between the coarse and colloidal dispersions. On the other hand, in small intestinal penetration, the levels of EP, ME, and AC in colloidal dispersions were higher than those in the other two dispersions. Moreover, adding colloidal particles to the dissolved drug (molecular dispersions) increased the drug's permeability through the small intestinal membrane. In conclusion, colloidal particles are produced when MBST is suspended. Furthermore, we showed that these colloidal particles enhance the absorption of the main ingredients of MBST.