The inclusion complex of Triptonide (TN) and 2,6-dimethyl-β-cyclodextrin (DM-β-CD) was prepared by saturated aqueous solution method. The TN/DM-β-CD inclusion complex was characterized by Fourier transform infrared spectrometry (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA), and the possible inclusion mode was inferred by 1H nuclear magnetic rosonace (NMR) and 2D ROESY. The Job's plot showed that the inclusion ratio of host and guest was 1:1. The stability constant of 2891 M−1 was determined by UV absorbance spectra. The result showed that the DM-β-CD was able to solubilize TN to level as high as 2.7 mg mL−1. The water solubility of inclusion complex was increased by 150 times. In vitro release experiments showed that the cumulative release rate of the inclusion complex reached 70% in 12 h, while the cumulative release rate of TN reached 70% in 120 h. The inclusion complex had important applications in medical field with higher activity, higher solubility and lower toxicity.
