CBUA-NO平衡溶解度和表观油水分配系数的测定

目的：测定2-（4-氯苄叉基）-3-羰基熊果酸-（2-硝氧乙基）酯（CBUA-NO）的平衡溶解度和表观油水分配系数。方法：HPLC法测定CBUA-NO在不同表面活性剂中的溶解度及其在不同pH磷酸盐缓冲液介质中的油水分配系数。结果：不同表面活性剂对CBUA-NO的增溶作用有差异,CBUA-NO在1 mg·L^-1聚山梨酯80中溶解度最大;正辛醇-水体系中,CBUA-NO油水分配系数随油/水比例的升高而增大,pH=7.6,O/W=1时,CBUA-NO的油水分配系数最大,lgP=2.02。结论：建立的方法准确、可靠,可快速测定CBUA-NO的平衡溶解度和表观油水分配系数,为其体内动态的进一步研究提供依据。

Determination of equilibrium solubility and apparent oil/water partition coefficient of CBUA-NO

OBJECTIVE To determine the equilibrium solubility and apparent oil/water partition coefficients (logP) of 2-(4-chlorobenzylidene)-3-O-ursolic acid-(2-nitroxyethyl) ester (CBUA-NO). METHODS A high performance liquid chromatography (HPLC) method was established to determine the equilibrium solubility of CBUA-NO in different surfactants. And the logP was tested in phosphate buffered saline (PBS) at different pH values. RESULTS The interaction between CBUA-NO and various surfactants was observed. The maximum solubility of CBUA-NO was found in 1 mg·L^-1 Tween-80. The lgP of CBUA-NO increased with the increase of oil/water ratio in n-octanol/buffer solution system. And the oil-water partition coefficients had a maximum value at pH=7.6, O/W=1,lgP=2.02. CONCLUSION The established method is accurate and repeatable, which can be used for the rapid determination of the equilibrium solubility and logP of CBUA-NO. These data provide the proof for profound study on the process in vivo.