油-吐温-醇-水体系伪三元相图在自微乳化制剂研究中的应用

Application of Pseudo-ternary Phase Diagrams for Oil-Tween-alcohol-water System in Self-microemulsifying Drug Delivery System

分别以油酸乙酯、亚油酸乙酯、乙酸乙酯为油相,吐温-80为表面活性剂,无水乙醇、正丙醇、异丙醇、乙二醇、1,2-丙二醇、丙三醇、正丁醇和聚乙二醇400为助表面活性剂,在37℃水浴中,用水滴定上述三组分不同配比的混合物,绘制油-吐温-80-醇-水体系伪三元相图,并对自微乳化系统进行研究。结果表明,相同条件下以乙酸乙酯为油相的体系,相图中自微乳区面积大于以油酸乙酯和亚油酸乙酯为油相的体系。随着体系中吐温-80-醇重量比(Km)减小,形成的自微乳区面积减小;若表面活性剂黏度较大,则以油酸乙酯和亚油酸乙酯为油相的体系相图中可出现凝胶区,随Km减小,凝胶区减小直至消失。

Self-microemulsions were prepared by titrating the mixture of oil, surfactant and cosurfactant with distilled water in 37℃ water bath and pseudo-ternary phase diagrams for these systems were conducted. Ethyl oleate, ethyl linoleate and ethyl acetate were used as oil phase, Tween-80 as surfactant and anhydrous ethanol, n-propanol, isopropanol, ethanediol, 1,2-propanediol, propanetriol, n-butanol and polyglycol 400 as cosurfactants, respectively. The results showed that the self-emulsion region area in the diagrams for the systems using ethyl acetate as oil phase was bigger than that of the systems using ethyl oleate and ethyl linoleate as oil phase in the same conditions. The self-microemulsion area decreased with the decreasing of the ratio of Tween-80 to alcohols(Km). The gel region appeared in the diagrams for the systems using ethyl oleate and ethyl linoleate as oil phase if higher viscosity cosurfactant was used and the gel region would disappear with the decreasing of Km.