盐酸多柔比星磁性热敏脂质体的制备和理化性质研究

Preparation and Property of Doxorubicin Magnetic Thermosensitive Liposomes

目的研究通过正交实验优化盐酸多柔比星磁性热敏脂质体(DOX-MTSLs)的制备工艺和处方,并检测其理化性质。方法采用逆相蒸发法结合硫酸铵梯度法制备盐酸多柔比星磁性热敏脂质体;采用微柱离心-RP-HPLC测定药物包封率;采用差示扫描量热分析仪测定相变温度;通过透射电镜和纳米激光粒度仪观察粒子粒径及粒径分布;采用恒温水浴透析法测定不同温度下的释药率,同时考察在(41±0.5)℃下的释药规律并拟合释药方程;采用高频感应加热设备检测盐酸多柔比星磁性热敏脂质体在体外交变磁场下的升温性能实验。结果盐酸多柔比星磁性热敏脂质体的最优处方工艺条件为:药物与磷脂质量分数(m/m)为1∶20,磷脂与胆固醇摩尔比为为4∶1,磁流体质量浓度为15 mg·mL-1,外水相pH值为7.4。所得3批盐酸多柔比星磁性热敏脂质体(批号100416、100507、100517自制)的包封率分别为(82.77±0.88)%,(83.03±1.38)%和(80.68±0.42)%(n=3);显著相变温度为40.03℃,平均粒径为177.1 nm,多分散指数(PDI)为0.700;盐酸多柔比星磁性热敏脂质体在(25±0.5)℃与(37±0.5)℃释放不显著,在10 h内仅分别达到释放率为15.45%与19.54%,在(41±0.5)℃时2 h内释放率达到90.99%,释放规律符合Higuchi动力学过程;在振荡频率80 kHz,电流12 A的高频交变磁场下,载磁量为3.19 mg·mL-1的盐酸多柔比星磁性热敏脂质体组在10 min内温度迅速上升至39.9℃,40 min达平稳时的温度为56.7℃。结论由最佳处方工艺条件制备的盐酸多柔比星磁性热敏脂质体包封率较高,热敏性和磁响应性均良好,达到实验预期目标。

OBJECTIVE To optimize the formulation of the doxorubicin magnetic thermosensitive liposomes （DOX-MTSLs） was optimized by orthogonal design and evaluated its property. METHODS DOX-MTSLs were prepared by reverse evaporation combined with（ NH4 ）2 SO4-gradient method. The entrapment efficiency was determined by mini-column centrifugation-RP-HPLC method. The transform temperature was determined by differential scanning caliorimetric （DSC）. The particle size and Zeta electric potential were measured by transmission electron microscopy（TEM） and the laser scattering particle size distribution analyzer. The in vitro release behavior of DOX-MTSLs at different temperatures and different time points were studied by dialyzer in constant temperature water and simulated the release regression equation at（41 ± 0. 5） ℃. The heating effect of DOX-MTSLs was determined in the high alternation magnetic field（AMF）. RESULTS The optimum recipe of DOX-MTSLs was founded as DOX/DPPC of 1：20（m/m）, DPPC/Chol of 4：1 （ mol/mol）, the concentration of magnetic fluid 15 mg · mL-1, pH value of 7.4. The average entrapment efficiency of three batches of DOX-MTSLs （ 100416,100507,100517 self-preparation） were （ 82. 77 ± 0. 88 ） %, （ 83.03 ± 1.38 ） % and （ 80. 68 ± 0. 42 ） % （ n = 3 ）. The average particle size of doxorubicin magnetic thermosensitive liposomes were 177.1 nm, and the polydispersity index（PDI） was 0. 700. When the temperature increased from（25 ± 0. 5 ）℃ to（ 37 ± 0. 5 ）℃, the in vitro drug release was very slow and incomplete （ 15.45% and 19. 54% ） even up to 10 h. However, at the phase transition temperature（Tin） 41 ℃ , the in vitro drug release significantly reached 90. 99% within 2 h and continued to release. The DOX-MTSLs was showed to be temperature dependent and the in vitro release model was fitting the kinetic equation of Higuchi at （41 ± 0. 5 ） ℃. The heating temperature and balanceable temperature of DOX-MTSLs（F3O4 3.19 mg · mL^-1 ） were respectively raised to 39. 9 ℃ in 10 min and to 56. 7 ℃ in 40 rain in high frequency induction heating equipment of oscillation frequency 80 kHz and current 12A. CONCLUSION The optimized conditions can be obtained with high entrapment efficiency, good thermosensitivity and perfect magnetic susceptibility to reach the expectation.