Abstract:The inclusion reaction of astilbin with β-cyclodextrin (β-CD) was investigated by UV spectrometry in this study. β-CD could form complex with astilbin in ratio of 1:1 with formation constant of 1788.54±273.41 M-1, and gradually decrease the absorbance of astilbin at 291 nm. The complex was prepared by co-grinding method. The effects of water content and molar ratio on inclusion rate during grind were investigated. The results showed that properly increasing of water content and β-CD molar ratio enhanced the formation of astilbin complexes. Finally, the solubility and in vivo bioavailability of astilbin and its β-CD complexes prepared with molar ratio of 1:2 were investigated. The solubility of astilbin in β-CD complexes was increased 106.14 times and its dissolution profiles were improved. The in vivo bioavailability study showed that β-CD enhanced the absorb rate of astilbin, shortened Tmax and increased Cmax. However, the absolute bioavailability between astilbin and its β-CD complexes had no difference, and were both around 3.7%.
