Photostability and antioxidant activity studies on the inclusion complexes of trans-polydatin with β-cyclodextrin and derivatives

The inclusion complexes of trans-polydatin and three cyclodextrins (CDs), namely β-cyclodextrin (β-CD), methyl-β-cyclodextrin (Me-β-CD) and (2-hydroxy) propyl-β-cyclodextrin (HP-β-CD) were prepared. The effects of the inclusion behavior of trans-polydatin with three kinds of CDs were investigated in both solution and the solid state with the following methods: phase-solubility, X-ray diffraction (XRD), thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM), proton nuclear magnetic resonance (1H-NMR) and two-dimensional rotational frame nuclear overhauser effect spectroscopy (2D ROESY). The results indicated that trans-polydatin formed a 1 : 1 stoichiometric inclusion complex with CDs. Meanwhile, the solubility and thermal stability of the inclusion complexes were improved after encapsulating by CDs. Furthermore, the photostability of trans-polydatin was enhanced after forming the inclusion complexes. The antioxidant activities results showed that the antioxidant performance of the inclusion complexes was enhanced in comparison to the native trans-polydatin. Therefore, it can be a potentially promising way to promote its drug bioavailability or phytochemical preparations.