桦木酸微乳的组成研究

目的研究桦木酸微乳的配方组成，并评价其质量。方法通过滴定法绘制三元相图，筛选微乳配方组成；建立桦木酸的HPLC测定法；考察微乳对桦木酸的增溶作用，及室温、40℃、光照条件下放置10d的稳定性。结果Cremophor RH40和Tween80均可形成微乳，随着Km（表面活性剂／乙醇的重量比）的增大，微乳区也增大，油相十四酸异丙酯和十六酸异丙酯对微乳区的影响不大，微乳在室温、40℃和以及光照的条件下一直呈澄清透明状态，说明微乳在这些条件下稳定。结论优选的最佳配方组成为Tween80-乙醇-十四酸异丙酯一水的比例为5：5：3：8．6。

The Formulation of Betulinic Acid Microemulsion

Aim To prepare and evaluate betulinic acid microemulsion. Methods The formulation was investigated by pseudoternary phase diagram obtained by titration method. The determination method of betulinic acid was established by HPLC. The solubilization of the microemulsion on betulinic acid was experimented, and the stability of the microemulsion after being placed under the condition of room temperature, 40℃, or illumination for 10 days was evaluated. Results Both Cremophor RH 40 and Tween80 were main formulation of the microemulsion. The size of microemulsion increased with Km （the weight ratio of surfactant to ethanol）. Oil phase formulation containing IMP or IPP had little effect on the size of the microemulsion. The microemulsion placed under the condition of room temperature, 40℃, or illumination for 10 days was stable. Conclusion The optimum formulation was as follows： tween80-ethanol-IPM-water = 5： 5： 3： 8.6.