载药蒙脱石/丙烯酸树脂微球的制备与体外释放性能的研究

目的以丙烯酸树脂为膜材制备载药蒙脱石/丙烯酸树脂微球并考察其体外释放性能。方法以盐酸倍他洛尔为模型药物,采用O/O溶剂挥发法制备蒙脱石载药微球,通过正交实验设计,考察柠檬酸三乙酯及甘油用量、乳化剂与膜材比例及用量、内外相体积比等因素对微球载药量、包封率、体外释放性能的影响,采用扫描电镜对其外观形态进行表征。结果所得微球外观圆整,粒径分布较均匀,平均粒径为20.7μm,平均载药量为14.31%±0.47%,平均包封率为94.35%±1.01%。结论该法制备载药蒙脱石丙烯酸树脂微球是可行的,体外释放研究表明微球具有一定的缓释作用。     

罗哌卡因-醋酸地塞米松PLGA微球的制备及体外释药特性研究

目的 制备罗哌卡因 醋酸地塞米松聚乳酸羟基乙酸共聚物（PLGA）微球（简称微球）并研究其体外释药特性。方法以PLGA为载体,采用W1/O/W2双重乳化 溶剂挥发法制备微球,研究实验过程中有机相PLGA浓度、外水相/有机相体积比、内水相体积、外水相聚乙烯醇（PVA）浓度几项因素变化对罗哌卡因 醋酸地塞米松PLGA微球粒径、表面形态﹑载药量﹑包封率和突释行为的影响。结果有机相PLGA浓度在制备微球的过程中是一个关键性因素。随着PLGA浓度增加,微球粒径增大,载药量﹑包封率明显提高,突释降低;外水相/有机相体积比增大,微球粒径增大, 载药量﹑包封率明显提高,微球表面更加光滑﹑微孔减少,突释降低;随着内水相体积增加使得微球表面的微孔明显增多,突释增加,载药量﹑包封率降低;当外水相PVA浓度由0.5%增加到2%,微球粒径变小,突释效应增加。通过优化条件制备的微球形状为球形,外观光滑圆整,粒径分布均匀,其中＞90%分布在20～70 μm。罗哌卡因载药量（7.48±0.33）%,包封率（70.97±2.36）%;醋酸地塞米松载药量（1.52±0.16）%,包封率（57.30±1.17）%。结论采用W1/O/W2双重乳化 溶剂挥发法成功制备罗哌卡因加醋酸地塞米松PLGA微球;以优化工艺制备的微球,在体外具有明显的缓释行为,释药曲线呈典型S形三阶段模式。     

口服利福平海藻酸钠微球的制备

［摘要］目的研制口服利福平海藻酸钠微球。方法采用静电液滴法制备利福平海藻酸钠微球，测定粒径大小、包封率、载药量及其影响因素，考察微球的体外释放特点。结果微球球形圆整，分散性好，平均粒径70.2 μm，包封率83.5%，载药量17.1%，在模拟肠液中的释放呈快慢相，时间长而药物释放完全。结论以海藻酸钠、硬脂酸为材料，用静电液滴法制备利福平微球，球径小、包封率高、释药时间长，工艺简便。     

吸附和包埋法制备洛美沙星淀粉微球及其体外释放比较研究

目的制备盐酸洛美沙星淀粉微球,并对其体外释药模式进行研究。方法以盐酸洛美沙星为模型药物,采用吸附载药法和包埋载药法制备了载药淀粉微球,通过测定微球载药量、包封率和在不同的释放介质中的体外释放情况,对上述2种方法制备的载药微球进行质量评价。结果吸附法制备的载药微球的平均载药量为14.54μg·mg^-1,药物包封率为39.72%;而包埋载药法制备的淀粉微球的平均载药量为19.32μg·mg^-1,药物包封率为48.95%。体外释药特性研究表明它们具有缓释特性,其中包埋载药法制备的淀粉微球比吸附载药法制备的淀粉微球有更好的缓释能力,在不同的释放介质中释药曲线也有所不同,在模拟胃液中累计释药量只能得到70%;而在模拟肠液中累计释药量能达到80%以上。结论吸附载药法和包埋载药法制备的载药淀粉微球都具有缓释作用,但后者体外释药具有更明显的缓释效果。     

阿司匹林缓释微球的制备及其体外释药性能研究

目的:制备阿司匹林缓释微球,并考察其体外释药性能。方法:采用改良的乳化溶剂挥发法,以聚乳酸-羟基乙酸共聚物(PLGA)为载体材料、载药量和包封率为指标,固定PLGA为100 mg正交设计试验优化阿司匹林缓释微球的阿司匹林用量、外水相体积、丙酮-二氯甲烷体积比和聚乙烯醇(PVA)浓度,对最优处方所制微球进行验证和体外释放度考察。倒置显微镜和电子显微镜下观察微球表面形态,激光粒度分析仪考察微球粒径。结果:PLGA为100 mg时的最优处方:阿司匹林用量为20 mg、外水相体积为150 ml、丙酮-二氯甲烷体积比为1∶1、PVA浓度为1 mg/100 ml;所制微球的平均粒径为139.95μm,电镜下微球表面光滑圆整,载药量为8.6%,包封率为33%,240 h体外累积释放度为85.56%。结论:成功制得具有明显缓释作用的阿司匹林缓释微球。     

低分子肝素聚乳酸-羟基乙酸缓释微球的研制

目的制备低分子肝素聚乳酸-羟基乙酸(LWMH-PLGA)缓释微球,观察微球表面形态,检测微球物理性能和体外释药行为。方法采用W1/O/W2复乳溶剂挥发法制作微球;通过扫描电镜观察微球的表面形态结构;利用天青A比色法测试微球中药物的载药量和包封率,并对微球中药物的体外释放行为进行研究。结果微球表面显现较多的孔隙,平均粒径为(2.55±0.94)μm,载药量为(14.79±1.03)%,包封率为(55.7±2.21)%;48 h的体外释放试验表明,LWMH累积释放率达到40%。结论 LWMH-PLGA微球能够稳定地释放药物LWMH,验证了PLGA微球作为LWMH控制释放载体的可行性。     

胸腺肽明胶微球的制备和体外释药的特性

目的:为提高胸腺肽的生物利用度,增强疗效,制备胸腺肽的明胶微球.方法:用乳化交联法制备胸腺肽明胶微球,正交设计法筛选其最佳制备工艺,Lowry法测定药物的含量,计算微球的载药量、包封率及体外释药量.结果:微球粒径范围为1.0～30.2 μm,平均粒径为14.64 μm,平均载药量为20.20%(w/w),平均包封率为80.82%,其体外释药符合Higuchi方程,稳定性考察实验结果表明其稳定性较好.结论:本法制备的胸腺肽明胶微球粒径分布集中,粒径大小符合设计要求,体外释药有明显的缓释作用,具有良好应用前景.     

bFGF-PLGA缓释微球及其体外释药性能研究

目的以bFGF为缓释药物、PLGA为药物载体制备bFGF-PLGA缓释微球,观察微球表面形态,检测微球物理性能和体外释药行为。方法采用W1/O/W2复乳溶剂挥发法制作微球;通过扫描电镜观察微球的表面形态结构;利用ELISA法测试微球中药物的载药量和包封率,并对微球中药物的体外释放行为进行研究。结果微球表面圆滑均匀,平均粒径(0.75±0.08)μm,载药量[(59.9±1.9)×10-3]%,包封率为(79.9±2.8)%;在为期45 d的体外释放试验中,bFGF累积释放率达到80%。结论bFGF-PLGA微球能够稳定地在较长时间释放药物bFGF,验证了PL-GA微球作为bFGF控制释放载体的可行性。     

玻璃体内注射用地塞米松微球的制备

目的为治疗增殖性玻璃体视网膜病变,制备玻璃体内注射用地塞米松微球。方法以生物可降解乙交酯和丙交酯的无规共聚物(PLGA)为载体材料,采用W/O型乳化-溶剂挥发方法制备地塞米松微微球。研究影响微球制备的工艺条件,考察了微球的粒径大小与分布、载药量和包封率,评价载药微球的体外释放行为。结果微球形态完整,表面光滑,微球的粒径范围为4.70±1.6μm,载药量为(15.5±0.32)%,包封率为(78.8±1.3)%。体外释药13d约90%,属扩散-溶蚀机制。结论制备方法可行,地塞米松PLGA微球具有药物缓释作用。可以作为玻璃体内注射用地塞米松的给药载体。     

尼莫地平聚乳酸缓释微球的制备及其药剂学性质

目的制备尼莫地平聚乳酸缓释微球,并对其药剂学性质进行研究.方法采用溶剂蒸发萃取法制备微球,正交实验设计考察影响制备工艺的因素,用扫描电镜观察微球表面形态,红外光谱分析验证舍药微球的形成,对制备的尼莫地平微球的粒径、栽药量、包封率等性质及体外释放特性进行了研究.结果尼莫地平聚乳酸微球的最佳制备工艺稳定,微球形态圆整,粒径分布适宜,药物确已被包裹于微球中.优化工艺制得的微球平均粒径为(61.7±0.46)μm,载药量为(53.2±0.8)%,包封率为(86.2±0.6)%,体外释放符合Higuchi方程,Q=17.708t1/2-0.975 8(r=0.995 4),t1/2=8.29 d.结论本实验获得了较理想的尼莫地平聚乳酸微球,其体外释药特性符合长效制剂特征.     

利福平丝素蛋白载药微球的制备及性能研究

目的通过测定利福平丝素蛋白微球的载药量、包封率及释放度,考察乳化转速、有机溶剂与丝素蛋白溶液比例,对微球的制备方法进行优化,筛选微球的最佳制备方法。方法采用乳化法制备利福平丝素蛋白微球,以不同转速、有机溶剂与丝素蛋白溶液不同比例分别制备利福平丝素蛋白微球,采用扫描电镜观察微球的形态,用紫外分光光度法测定微球的载药量、包封率及释放度,以形态、载药量、包封率及释放度为指标,筛选微球的最佳制备方法。在此基础上,采用最佳处方制备3批利福平丝素蛋白微球,对微球的形态、粒径、包封率、载药量和释放度进行考察。结果有机溶剂与丝素蛋白溶液体积比为4∶1、转速为200 r·min^-1时所得利福平丝素微球形态均匀,近似球形,载药量和包封率较高,所得载药微球有较好的缓释作用。以最佳处方制得微球载药量为66.1%±0.87%,包封率为87.80%±2.23%。结论有机溶剂与丝素蛋白溶液体积比为4∶1、转速为200 r·min^-1时载药量、包封率和释放度较好,故选择此处方为利福平丝素蛋白微球的最佳制备处方。     

Preparation and characterization of ibuprofen microspheres

Ibuprofen was microencapsulated with Eudragit RS using an o/w emulsion solvent evaporation technique. The effects of three formulation variables including the drug:polymer ratio, emulsifier (polyvinyl alcohol) concentration and organic solvent (chloroform) volume on the entrapment efficiency and microspheres size distribution were examined. The drug release rate from prepared microspheres and the release kinetics were also studied. The results demonstrated that microspheres with good range of particle size can be prepared, depending on the formulation components. The drug:polymer ratio had a considerable effect on the entrapment efficiency. However, particle size distribution of microspheres was more dependent on the volume of chloroform and polyvinyl alcohol concentration rather than the drug:polymer ratio. The drug release pattern showed a burst effect for all prepared microspheres due to the presence of uncovered drug crystals on the surface. It was shown that the release profiles of all formulations showed good correlation with the Higuchi model of release.     

Preparation and characterization of ibuprofen microspheres

Ibuprofen was microencapsulated with Eudragit RS using an o/w emulsion solvent evaporation technique. The effects of three formulation variables including the drug:polymer ratio, emulsifier (polyvinyl alcohol) concentration and organic solvent (chloroform) volume on the entrapment efficiency and microspheres size distribution were examined. The drug release rate from prepared microspheres and the release kinetics were also studied. The results demonstrated that microspheres with good range of particle size can be prepared, depending on the formulation components. The drug:polymer ratio had a considerable effect on the entrapment efficiency. However, particle size distribution of microspheres was more dependent on the volume of chloroform and polyvinyl alcohol concentration rather than the drug:polymer ratio. The drug release pattern showed a burst effect for all prepared microspheres due to the presence of uncovered drug crystals on the surface. It was shown that the release profiles of all formulations showed good correlation with the Higuchi model of release.     

Box-Behnken效应面法优化塞来昔布微球制备工艺

目的：制备塞来昔布聚乳酸-羟基乙酸共聚物（PLGA）载药微球,优化其处方和制备工艺,考察其体外释药行为。方法：分别以油相中PLGA浓度、水相PVA浓度和油/水相体积比为考察因素,以包封率为考察指标,采用Box-Behnken效应面法优化塞来昔布微球的处方和工艺;透析袋法评估其体外释放能力。结果：塞来昔布PLGA微球的最佳处方工艺条件为：PLGA浓度75 g·L^-1,水相PVA体积分数1.5%,油/水相体积比1∶30。所制备的微球形态圆整,大小均一,实测包封率为66.1%,与预测值67.3%相比,偏差为1.8%。最优处方体外14 d累积释药56%,体外释放曲线符合Higuchi方程。结论：Box-Behnken效应面法简便可行,可用于优化塞来昔布PLGA微球的制备,微球体外释放具有缓释效果。     

Preparation and investigation the release behaviour of wax microspheres loaded with salicylic acid

Salicylic acid-beeswax microspheres were prepared by melt dispersion technique. The effects of formulation parameters on the microscopic characteristic, drug loading and cumulative amount of released drug were investigated by experimental design. Results showed that all of the microparticles were spherical with porous surfaces. The average size of microspheres was 24-48 microm, the drug content was in the range of 22-45% and the encapsulation efficiency was 46-93%. Drug loading was influenced by emulsification speed as a main factor. All the microspheres had a burst release initially. The emulsifier concentration did not have a significant effect on drug release. The release behaviour of microspheres conformed best to Korsmeyer-Peppas semi-empirical model and the release of SA from beeswax microspheres was Fickian (n < 0.45).     

Evaluation of furosemide-loaded alginate microspheres prepared by ionotropic external gelation technique

Alginate microspheres containing furosemide were prepared by the ionotropic external gelation technique using Ca2+, Al3+ and Ba2+ ions. The incorporation efficiency of the prepared microspheres ranged between 65% and 93%. The effect of sodium alginate concentration, cross-linking ions and drying conditions was evaluated with respect to entrapment efficiency, particle size, surface characteristics and in vitro release behavior. Infrared spectroscopic study confirmed the drug-polymer compatibility. Differential scanning calorimetric analysis revealed that the drug was molecularly dispersed in the alginate microsphere matrices. Scanning electron microscopic study of microspheres showed the rough surface due to higher concentration of drug molecules dispersed at molecular level in the alginate matrices. The mean particle size and entrapment efficiency were found to be varied by changing various formulation parameters. The in vitro release profile could be altered significantly by changing various formulation parameters to give a sustained release of drug from the microspheres. The kinetic modeling of the release data indicate that furosemide release from the alginate microspheres follow anomalous transport mechanism after an initial lag period when the drug release mechanism was found to be Fickian diffusion controlled.     

β-methasone-containing biodegradable poly(lactide-co-glycolide) acid microspheres for intraarticular injection: effect of formulation parameters on characteristics and in vitro release

A sustained drug release system based on the injectable poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with β-methasone was prepared for localized treatment of rheumatic arthritis. The microscopy and structure of microspheres were characterized by scanning electron microscope (SEM) and Fourier transform infrared (FTIR). The effects of various formulation parameters on the properties of microspheres and in vitro release pattern of β-methasone were also investigated. The results demonstrated that increase in drug/polymer ratio led to increased particle size as well as drug release rate. Increase in PLGA concentration led to increased particle size, but decreased burst release. The drug encapsulation efficiency increased sharply by increasing polyvinyl alcohol (PVA) concentration in the aqueous phase from 1.5 to 2.0%. β-methasone release rate decreased considerately with decreasing OP (organic phase)/AP (aqueous phase) volume ratio. Stirring rate had significantly influence on the particle size and encapsulation efficiency. Independent of formulation parameters, β-methasone was slowly released from the PLGA microspheres over 11 days. The drug release profile of high drug loaded microspheres agree with Higuchi equation with a release mechanism of diffusion and erosion, that of middle drug loaded microspheres best agreed with Hixcon-Crowell equation and controlled by diffusion and erosion as well. The low drug loaded microspheres well fitted to logarithm normal distribution equation with mechanism of purely Fickian diffusion.     

Preparation and investigation the release behaviour of wax microspheres loaded with salicylic acid

Salicylic acid-beeswax microspheres were prepared by melt dispersion technique. The effects of formulation parameters on the microscopic characteristic, drug loading and cumulative amount of released drug were investigated by experimental design. Results showed that all of the microparticles were spherical with porous surfaces. The average size of microspheres was 24–48 µm, the drug content was in the range of 22–45% and the encapsulation efficiency was 46–93%. Drug loading was influenced by emulsification speed as a main factor. All the microspheres had a burst release initially. The emulsifier concentration did not have a significant effect on drug release. The release behaviour of microspheres conformed best to Korsmeyer-Peppas semi-empirical model and the release of SA from beeswax microspheres was Fickian (n < 0.45).     

Optimization of formulation variables for the development of long acting microsphere based depot injection of olanzapine

This work was aimed to optimize the composition of microspheres of olanzapine to design long acting depot injection for the treatment of psychosis. Solvent evaporation method was used for the fabrication of microspheres. Different formulation variables for the solvent evaporation method, viz., effect of theoretical drug loading, type of surfactant and its concentration, temperature, volume of external phase and presence of salt in external aqueous phase, conditions and time of solvent evaporation and drying methodology were optimized. The microspheres were characterized for encapsulation efficiency, particle size, surface morphology, residual solvent content, drug release profile and drug release kinetics. The optimized formulation showed consistent drug release for upto 14 days time period.     

Optimization of formulation variables for the development of long acting microsphere based depot injection of olanzapine

This work was aimed to optimize the composition of microspheres of olanzapine to design long acting depot injection for the treatment of psychosis. Solvent evaporation method was used for the fabrication of microspheres. Different formulation variables for the solvent evaporation method, viz., effect of theoretical drug loading, type of surfactant and its concentration, temperature, volume of external phase and presence of salt in external aqueous phase, conditions and time of solvent evaporation and drying methodology were optimized. The microspheres were characterized for encapsulation efficiency, particle size, surface morphology, residual solvent content, drug release profile and drug release kinetics. The optimized formulation showed consistent drug release for upto 14 days time period.