避蚊胺乙基纤维素微球的制备及其性质考察

Preparation and evaluation of DEET-ethylcellulose microsphere

目的 :制备避蚊胺乙基纤维素微球 ,考察其性质。方法 :采用溶剂挥发法制备避蚊胺乙基纤维素微球。将乙基纤维素溶于二氯甲烷中 ,滴入避蚊胺 ,密闭超声溶解 ,作为分散相。配制 1%聚乙烯醇水溶液作为连续相。 10 0 0 r/ min搅拌下将分散相缓缓加入连续相中 ,30 min后降低搅速至 6 0 0 r/ min继续搅拌直至二氯甲烷挥干。离心 ,蒸馏水洗 ,冷冻干燥 12 h即得 ,并用扫描电镜观察微球外观 ,光学显微镜下计数 5 0 0个微球考察粒径分布 ,HPL C法 (Diam onsil ODS柱 15 0 mm× 4 .6 mm,流动相为甲醇∶水 =6 5∶ 35 ,检测波长 2 10 nm,流速 1m l/ min) ,建立标准回归方程测定载药量和药物包封率。 结果 :所得微球为乳白色微粒 ,外观圆整 ,粒径 90 %分布在 30～ 70 μm范围内 ,平均算术径 (dar)及平均球径 (dv)分别为 4 9.6 μm和 5 1.2 μm,微球载药量为 18.7% ,包封率可达 5 6 .1% (n=6 )。 结论 :该成球方法简便易行。

Objective:To prepare DEET-ethylcellulose microsphere(DEET-EC) and observe its properties to retard volatilization of DEET. Methods: DEET-EC was prepared with solvent evaporation method. DEET was dissolved in CH 2Cl 2 with EC served as dispersed phase and 1% PVA water solution as continuous phase. The dispersed phase was added into the continuous phase with stirring rate at 1 000 r/min. The stirring rate was changed into 600 r/min after 30 min, and was kept until CH 2Cl 2 was entirely volatilized. After being watered, precipitated and lyophilized for 12 h, DEET-EC was derived, and the shape was observed with electron microscope. The particle size distribution was detected in 500 microspheres with optical microscope. HPLC method was established to determine the embedding ratio and loaded ratio of DEET-EC microsphere. Chromatograph conditions: Diamonsil ODS column (150 mm×4.6 mm), CH 3OH∶H 2O=65∶35 as mobile phase at 1 ml/min, the detected wavelength 210 nm. Results: The DEET-EC was egg-white and had spherical shape. Almost 90% of the MS distributed in 30-70 μm, while ( ar ) and ( v ) were 49.6 μm and 51.2 μm, respectively. The loading ratio was 18.7% and the embedding ratio was 56.1%(n=6). Conclusion: The solvent evaporation method is convenient and simple to prepare DEET-EC microsphere.