A solid preparation of phytochemicals: Improvement of the solubility and bioavailability of Astragaloside IV based on β-cyclodextrin microencapsulation

Astragaloside IV/β-cyclodextrin inclusion complex(AsIV/β-CD IC) was successfully prepared by low-temperature sedimentation technology. Under the preparation conditions inclusion temperature 60℃, inclusion time 3h, core-wall material molar ratio 1:1, and inclusion rate 750 rpm, ­­­the optimal encapsulation efficiencyreached 81.63%. It was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and thermogravimetric (TGA). Physicochemical characterization of the AsIV/β-CD IC indicated that the complexation of AsIV/β-CD was successful, and the thermal stability of AsIV wasimproved clearly. Through granulation technology, astragalus saponin granules (ASG) with uniform size from AsIV/β-CD IC were obtained. ASG possessed significant water-solubility and storage stability beside fine taste. In addition, ASG demonstrated beneficial bioactivity in antioxidant and antibacterial functions. Antioxidative stress detection showed that ASG could inhibit the increase of MDA content and the decrease of SOD content in cells caused by LPS. In addition, in vitro antibacterial experiments of ASG showed that ASG has obvious antibacterial activity against 6 strains, especially the MIC value of Escherichia coli and Bacillus subtilis reached 12.5 mg/mL.