Three-dimensional structure of beads self-assembled by cyclodextrin using synchrotron radiation X-ray microcomputed tomography / 药学学报

ABSTRACT

Beads, a novel drug delivery system self-assembled by cyclodextrins (CDs) and oil, has potential applications in the solidification of oil drugs and improving the bioavailability of lipid-soluble drugs. However, very few researches were dedicated to the mechanism of beads formation. In this study, three-dimensional structures of beads were visualized and investigated using synchrotron radiation X-ray microcomputed tomography (SR-μCT). The structural changes of beads attributed by drying process were analyzed and confirmed via visualization results of SR-μCT. Productively, it was proposed that Pickering emulsion droplets obtained during beads formation process were spatially localized orderly. Moreover, the effects of loading lipid soluble drug, namely, vitamin K1, on the structural changes of beads were also analyzed. It is well known that the surface tension of oil phase could be changed by the addition of lipid soluble constituents. It was reasonable that the three-dimensional structure of beads might be altered during the drug loading of vitamin K1 into the beads. However, although the morphologies of beads were changed to some extent, the ordered Pickering emulsion droplets during the process of beads formation was successfully illustrated based on the SR-μCT results. Conclusively, according to the three-dimensional structural analysis of the beads, this study revealed the organized architecture for Pickering emulsion droplet assembly and beads formation in cyclodextrin semi-inclusion complex, which significantly complements the formation mechanism of beads, and provides a structural basis for the further study of beads.