落新妇苷-β-环糊精包结物的溶解性及生物利用度研究

Solubility and in vivo Bioavailability of Astilbin-β-cyclodextrin Complexes

摘要:

本文通过紫外吸收光谱法研究了落新妇苷与β-环糊精（β-CD）的包结反应。β-CD可与落新妇苷形成1:1包结物，并使其在291 nm处吸光度有规律下降，二者包结平衡常数为1788.54±273.41 M-1。采用研磨法制备落新妇苷与β-CD的包结物，考察了水分含量和摩尔比对落新妇苷包结率的影响。适当提高研磨过程中水份含量和β-CD摩尔比可增加落新妇苷包结率。最后，比较了β-CD包结物和落新妇苷单体的溶解度、体外溶出度和大鼠体内生物利用度。形成β-CD包结物可显著提高落新妇苷溶解度。25 ℃条件下，包结物中落新妇苷的溶解度为52.01 mM，为落新妇苷单独存在时的106.14倍。体外溶出度曲线表明包结物中落新妇苷的溶解速度更快。包结物中落新妇苷在大鼠体内达到峰值时间更短，且峰值浓度更高，但二者生物利用度相当，绝对生物利用度都约为3.7%。

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%.