利福平缓释微球的制备及释放特性的实验研究

发布时间：2018-06-06 03:34

本文选题：聚乳酸/羟基乙醇酸 + 利福平　；参考：《第二军医大学》2014年硕士论文

【摘要】：研究目的：通过制备聚乳酸/羟基乙醇酸共聚物（PLGA）-利福平缓释微球，研究微球的粒径、包封率、载药量和体外释放特点，同时兔椎旁植入PLGA-利福平缓释微球后，观察局部组织中的利福平浓度以及微球突释和缓释特点，研究微球的体内释放特点，从而明确利福平缓释微球在脊柱结核治疗中的作用和应用前景，并且为将来进行同类实验以及临床应用奠定实验基础。研究内容及结果：研究内容：（1）用乳化溶剂挥发法（W/O/W）制备PLGA-利福平缓释微球；（2）以包封率、载药量和体外释放度为评价指标，单因素考察PLGA平均分子量（Mw）、初乳制备方式、搅拌速度、内水相体积等因素对微球粒径、包封率和释放度的影响，优化微球制备处方；（3）采用紫外分光光度计测定PLGA-利福平缓释微球的载药量和包封率；（4）使用扫描电镜对PLGA-利福平缓释微球进行形态学观察，并测量其粒径大小及分布；（5）使用PBS液为释放介质，观察PLGA-利福平缓释微球在不同温度下的稳定情况，并研究其体外释放特点；（6）应用高效液相色谱法（HPLC）建立利福平标准曲线，以测量血浆及组织标本中利福平药物浓度；（7）兔脊柱旁开槽，局部给予PLGA-利福平缓释微球，，研究PLGA-利福平缓释微球在体内的释放特点。结果：（1）PLGA-利福平缓释微球形态圆整，表面光滑，肉眼观呈橙红色；（2）优化的处方：1:1的PLGA503H（Mw65000）和PLA共200mg，溶解于2ml二氯甲烷中，再加入1%PVA饱和溶液20ml中，400rpm搅拌20min，再转移至100ml0.2%PVA饱和溶液中，600rpm搅拌挥发溶剂4h；（3）PLGA-利福平缓释微球的载药量为42.95%，包封率为87.83%；（4）微球粒径分布呈近似正态分布，平均粒径124um；（5）利福平缓释微球体外释放特点：微球体外释放呈零级模式，24h突释低于25%，两周释放可达81%；（6）利福平缓释微球的体内释放特点：将利福平缓释微球和利福平原药按比例植入兔椎旁后，腰6椎体及腰大肌测得的利福平浓度均可维持在结核杆菌最低抑菌浓度（MIC）以上持续到术后28d，但是利福平缓释微球椎旁给药组的腰6椎体及腰大肌的利福平浓度下降趋势较利福平原药椎旁给药组更平缓，持续时间更长，同时肝、肺等其它组织未见明显蓄积。结论：(1)用乳化溶剂挥发法（W/O/W）制备的PLGA-利福平缓释微球，平均粒径为124u m，其外观、载药量、包封率等评价指标优良；(2)适当比例的投药比、内水相体积、搅拌速度、载体材料等参数值对微球的包封率、载药量及释放行为的影响很大；（3）PLGA-利福平缓释微球体外释放稳定，微球的释放呈零级模式，24h突释低，释放周期长；（4）PLGA-利福平缓释微球在兔椎旁用药后，腰6椎体及腰大肌测得的利福平浓度可维持在结核杆菌最低抑菌浓度（MIC）以上持续到术后28d，并且局部利福平浓度下降趋势平稳，肝、肺等其它组织未见明显蓄积。
[Abstract]:Objective: to study the particle size, encapsulation efficiency, drug loading and release characteristics of poly (lactic acid) / hydroxy glycolic acid copolymers (PLGA-rifampicin) sustained-release microspheres. To observe the concentration of rifampicin in local tissues and the characteristics of sudden and sustained release of microspheres, and to study the characteristics of release of microspheres in vivo, so as to clarify the role and application prospect of rifampicin microspheres in the treatment of spinal tuberculosis. And lay the experimental foundation for the similar experiment and clinical application in the future. Contents and results of the study: Preparation of PLGA-rifampicin sustained-release microspheres by emulsified solvent volatilization method (W / O / W). The encapsulation efficiency, drug loading and release rate in vitro were used as the evaluation indexes. The average molecular weight of PLGA, the preparation method of colostrum, and the stirring rate were investigated by single factor. The effects of the volume of internal water phase on the particle size, encapsulation efficiency and release rate of the microspheres, The optimized preparation of microspheres was used to determine the drug loading and encapsulation efficiency of PLGA-rifampicin sustained-release microspheres by UV spectrophotometer. The morphology of PLGA-rifampicin sustained-release microspheres was observed by scanning electron microscope (SEM). The particle size and distribution of the microspheres were measured. The stability of PLGA-rifampicin sustained release microspheres at different temperatures was observed by using PBS solution as the release medium, and the release characteristics in vitro were studied. The standard curve of rifampicin was established by high performance liquid chromatography (HPLC). To study the release characteristics of PLGA-rifampicin sustained-release microspheres (PLGA-rifampicin sustained-release microspheres) were used to measure the concentration of rifampicin in plasma and tissue samples. Results the microspheres with smooth shape, smooth surface and orange red eye were optimized for the formulation: 1: 1: 1: 1 PLGA 503H Mw65000) and PLA 200mg, dissolved in 2ml dichloromethane. After stirring for 20 minutes in the saturated solution of 1%PVA, 20ml, and then transferred to the saturated solution of 100ml0.2%PVA for 20 minutes, the amount of drug loaded in the volatile solvent of 4hu ~ (3) and lifampicin was 42.95 and the entrapment efficiency was 87.83 ~ (3) the particle size distribution of the microspheres was approximately normal, and the particle size distribution of the microspheres was similar to that of the 100ml0.2%PVA saturated solution, and the particle size distribution of the microspheres was approximately normal. Characteristics of in vitro release of rifampicin sustained-release microspheres: in vitro release of rifampicin microspheres was in a zero-order mode with a sudden release of less than 25% in 24 hours and up to 81% in two weeks. In vivo release characteristics of rifampicin sustained-release microspheres: rifampicin sustained-release microspheres and rifampicin microspheres were released in vivo: rifampicin sustained release microspheres and rifampicin microspheres were released in vivo. The original drug was implanted into rabbit paravertebral vertebrae in proportion. The concentration of rifampicin measured in lumbar 6 vertebra and psoas major muscle can be maintained above the minimum inhibitory concentration of Mycobacterium tuberculosis (MIC) until 28 days after operation, but the rifampicin concentration in the lumbar 6 vertebrae and psoas major muscle of rifampicin sustained-release microsphere paravertebral delivery group is below the concentration of rifampicin in the lumbar vertebrae and psoas major muscle. The descending trend was more gentle than that of rifampicin paravertebral administration group. It lasted longer, while other tissues, such as liver and lung, did not accumulate significantly. Conclusion the PLGA-rifampicin sustained-release microspheres prepared by the emulsified solvent volatilization method (W / O / W) have an average particle size of 124u m.The appearance, drug loading and encapsulation efficiency of PLGA-rifampicin microspheres are excellent. The effects of carrier material and other parameters on encapsulation efficiency, drug loading and release behavior of microspheres were significant. The release of PLGA-rifampicin sustained-release microspheres was stable in vitro, and the release of microspheres was in zero order mode. After sustained release of PLGA-rifampicin microspheres in rabbit paravertebral, the concentration of rifampicin measured in lumbar 6 vertebrae and psoas major muscle could be maintained above the minimum inhibitory concentration of Mycobacterium tuberculosis (MIC) until 28 days after operation, and the decrease of local rifampicin concentration was stable. There was no obvious accumulation of liver, lung and other tissues.
【学位授予单位】：第二军医大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R943

【参考文献】