改性果胶的合成优化及用于水飞蓟素微乳的制备

The Optimize of Synthesis Reaction Condition of Modified Pectin and the Preparation of Silymarin Microemulsion

以果胶和樟树籽油为反应底物,以改性果胶的取代度为指标,通过单因素试验优化脂肪酶RMIM添加量、底物质量比(果胶与樟树籽油)、油浴温度、反应时间等合成条件。以果胶及其衍生物为乳化剂制备水飞蓟素微乳,以乳化后的粒径、zeta电位、水飞蓟素饱和溶解度为指标,筛选油相、乳化剂、助乳化剂,比较果胶及果胶酯的助微乳化效果。结果表明:其最佳条件为脂肪酶RMIM添加量15%,底物质量比(果胶与樟树籽油)1︰2(g/g),油浴温度60℃,反应时间24 h,得到的产物取代度为62.4%;含5%水飞蓟素、油相樟树籽油、果胶/果胶酯水溶液与1,2-丙二醇形成混合乳化剂的质量比2︰1(g/g),油相、混合乳化剂与水飞蓟素质量比1︰8.5︰0.5时可获得较好的微乳效果。2种微乳制品(果胶与果胶酯)平均粒径分别为502.67±14.63 nm,462.67±14.63 nm,zeta电位分别为-45.3±0.1,-46.8±0.3,水飞蓟素的饱和溶解度分别为53.84±0.81 mg/mL,56.89±1.33 mg/mL。此外,2种微乳与市售水飞蓟素胶囊在12 h的释放百分率分别为46.67%±1.71%,55.80%±2.67%,32.28%±0.20%,由此可见,改性后的果胶酯微乳效果比原果胶要好。

The pectin and camphor oil used as reaction substrates, and the degree of substitution of modified pectin used as index, through the single factor experiment, optimize the dosage of lipase RMIM, substrate mass ratio（pectin︰camphor）, oil bath temperature, reaction time, etc. Pectin and its derivatives were used as emulsifiers to prepare microemulsion, and particle size, zeta potential, silymarin saturated solubility were used as the evaluation indexes to screen the oil, surfactant and cosolvent. The effect of pectin and its derivatives promoting microemulsion was compared. The result showed that the optimum condition was the content of lipase RMIM 15%, substrate ratio（pectin and CCSO） 1︰2（g/g）, the temperature of oil bath 60 ℃, the reaction time 24 h, and the degree of substitution 62.4%; when the formulation contained 5% silymarin using CCSO as oil, pectin and its derivatives solution as surfactant and 1, 2-propylene glycol as cosolvent, the ratio of mixed emulsifier which was prepared by pectin and its derivatives and 1, 2-propylene glycol was set at 1︰2, the proportion of oil, mixed emulsifier and silymarin was 1︰8.5︰0.5. The average diameter of two kind of preparation was 502.67±14.63 nm and 462.67±14.63 nm respectively, zeta potential was-45.3±0.1,-46.8±0.3 respectively and silymarin saturated solubility were 53.84±0.8 mg/mL, 56.89±1.3 mg/mL respectively. In addition, the accumulation release percentage of silymarin from these two kind of microemulsion and commercial capsule for 12 h were 46.67%±1.71%, 55.8%±2.67%, 32.28%±0.20%, thus the effect of modified pectin was better than the original one to promote microemulsion.