阿司匹林壳聚糖纳米缓释微球的制备及体外释放性能的研究

以自制阿司匹林为药物,壳聚糖为载体,采用乳化-化学交联法制备了阿司匹林-壳聚糖载药微球,确定了阿司匹林-壳聚糖载药微球的制备工艺条件,探讨搅拌速度、阿司匹林/壳聚糖质量比、交联剂戊二醛、乳化剂Span-80用量对微球的药物包封率、载药量和释药性能的影响。研究结果表明,室温条件下,以液体石蜡为介质,选用3%的壳聚糖冰醋酸溶液、按阿司匹林∶壳聚糖=1.5∶1、4%的戊二醛为交联剂、Span-80用量为体积比6%、中等搅拌速度制备出的微球药物包封率可达79%,微球粒径最小可达20 nm,制得的载药微球在16 h内对药物有良好的缓释作用,在25 h之内仍存在缓药效果。     

吡虫啉微球/聚乙烯醇复合液缓释性能研究

以聚乳酸、吡虫啉为原料,明胶为稳定剂,制备了吡虫啉微浮球悬液,将悬浮液、增粘剂淀粉、成膜基材聚乙烯醇复配得到吡虫啉微球/聚乙烯醇(IMD-PLA-PVA)复合液。微球分散性好,表面光滑平整。微球的粒径主要分布在0.5μm～5μm,体积平均粒径为8.2μm。红外光谱表明吡虫啉已成功复配到聚乳酸微球。吡虫啉微球/聚乙烯醇(IMD-PLA-PVA)复合液较吡虫啉/聚乙烯醇(IMD-PVA)复合液具有双重缓释效果。     

PVA-SA复合微球的制备及性能研究

用溶液共混法制备聚乙烯醇-海藻酸钠(PVA-SA)复合微球,考察了SA质量分数、PVA质量分数、CaCl2质量分数、m(PVA)/m(SA)和干燥方式对PVA-SA复合微球制备的影响,并测定了微球的含水率、溶胀率、载药量和包封率,通过红外光谱(FTIR)对微球进行了表征,研究了不同m(PVA)/m(SA)的PVA-SA复合微球对药物的缓释作用。结果表明,SA质量分数为6%,PVA质量分数为10%,CaCl2质量分数为5%,m(PVA)/m(SA)为1∶3时,可以制备出各项性能较好的微球,其载药率30.24%,包封率90.11%,并且有良好的缓释效果。     

单分散性PLGA磁性微球制备及其缓释性研究

为获得单分散性PLGA磁性微球,文中以纳米四氧化三铁明胶分散液作为内水相(W1),PLGA（聚乳酸羟基乙酸共聚物）的二氯甲烷溶液作为油相(O),PVA（聚乙烯醇）水溶液作为外水相(W2),利用T型微通道并采用复合乳液法制备PLGA磁性微球,考察流速比和油相与内水相体积比对微球制备的影响。借助FTIR、SEM及VSM（振动样品磁强计）对磁性微球组分、形貌、粒径分布和磁学性能进行表征;并以阿司匹林作为药物模型进行缓释性测试。结果表明：流速比v(W2):v(W1/O)=120:1且体积比V(O):V(W1)=2:1时可均匀成球,其粒径分布系数CV值仅为4.66%,表现出良好单分散性;此时比饱和磁化强度可达1.52emu/g,兼具优异顺磁性。制得的载药微球在60h内表现出阶段性匀速释放,且有较好磁响应性,有望用于磁响应性药物载体。     

壳聚糖载药微球的制备方法及在医药领域的应用

壳聚糖是唯一的天然碱性多糖,其优异的生物学特性使之成为药物载体领域研究的热点.综述了壳聚糖微球常见的制备方法,阐述了壳聚糖微球作为药物载体在医药领域的应用,介绍了药物包覆在微球中后,不仅达到了药物缓释控释的目的,还增加了其靶向性、降低了药物毒副作用.因此,对新型药物载体材料的研究及新型医药产品的开发有着重要意义.     

含紫杉醇PLGA缓释微球的研制及理化性质

目的研制含紫杉醇的聚乳酸和乙醇酸的共聚物[Poly(lactic-co-glycolic acid),PLGA]生物可降解高分子微球,并对其药物释放动力学进行分析。方法使用相对分子质量为20000的PLGA作为造粒对象,对不同溶剂的PLGA溶液进行喷雾化造粒,以优化出最佳造粒参数。在此条件下对含紫杉醇的PLGA溶液进行喷雾化造粒,制备紫杉醇/PLGA微球。结果形成单分散粒子的条件是较高的应用电压和较低的溶液流率,5%(wt)的PLGA溶液浓度溶于5∶1的氯仿和DMF的混合溶剂(v/v)中。在优化的喷雾参数下,得到了粒径均一、直径为300nm的单分散载紫杉醇的PLGA微粒。当紫杉醇在微球中含量较低时(2%),药物释放呈零级释放模式。较高的载药浓度(>5%)会在初期有轻微药物突释,然后呈零级释放模式。结论电喷雾化技术制备载药微粒是简单可行的新制药技术。含紫杉醇的PLGA微粒有望成为新一代抗癌药物剂型。     

单分散性PLGA磁性微球的制备及其缓释性

为获得单分散性PLGA磁性微球,以纳米四氧化三铁明胶分散液作为内水相(W1),PLGA(聚乳酸羟基乙酸共聚物)的二氯甲烷溶液作为油相(O),PVA(聚乙烯醇)水溶液作为外水相(W2),利用T型微通道并采用复合乳液法制备PLGA磁性微球,考察油相(O)质量浓度、外水相(W2)质量分数、流速比及油相与内水相体积比对微球制备的影响。借助FTIR、SEM、光学显微镜及VSM(振动样品磁强计)对磁性微球组分、形貌、粒径分布和磁学性能进行表征;并以阿司匹林作为药物模型进行缓释性测试。结果表明:油相中PLGA质量浓度为0.050kg/L,外水相(W2)中PVA质量分数为1%及2%,流速比v(W2)∶v(W1/O)=120∶1且体积比V(O)∶V(W1)=2∶1时可均匀成球,其粒径分布系数CV值仅为4.66%,表现出良好的单分散性;此时,比饱和磁化强度可达1.52emu/g,兼具优异顺磁性。制得的载药微球在60 h内表现出阶段性匀速释放,且有较好的磁响应性,有望用于磁响应性药物载体。     

伊维菌素缓释微球注射液制备工艺研究

以乳化溶剂挥发法制备伊维菌素(IVM)聚乳酸(PLA)微球,用该微球制备注射液并进行质量控制研究。采用Central Composite试验设计,对微球制备中的搅拌速度、投料比IVM:PLA、聚乙烯醇浓度3个因素进行响应面优化;采用L16(34)正交实验对助悬体系进行优化;制备IVM缓释微球注射液并进行质量评价。研究结果表明：优化后的搅拌速度为651 r/min,投料比为7:16,PVA浓度为1.47%,此条件下微球载药率为29.4%;优化后的助悬体系为微球粒径80μm,微球、吐温20与羟甲基纤维素钠含量分别为2.5%、1.5%、1%,在此条件下注射液沉降体积比为91.5%;经测定注射液的平均pH为7.2,体外20d内可以平稳释放,达到缓释效果,稳定性良好,这一研究过程为IVM缓释微球注射液的工业制备及在临床上安全应用奠定了一定基础。     

阿维菌素凝胶微球制备及其缓释性能研究

以壳聚糖(CS)和海藻酸钠(ALG)为包封材料,以阿维菌素(AVM)为芯材,采用锐孔法制备了阿维菌素-海藻酸钠-壳聚糖微球,考察了海藻酸钠质量分数、壳聚糖质量分数、氯化钙质量分数和芯壁体积比(质量分数1%的阿维菌素乳液与质量分数3%海藻酸钠溶液的体积比)对微球形态及包埋率的影响,利用SEM、FTIR等对微球结构及性质进行了表征,并考察了其在土壤中的缓释性能和释药机制。结果表明,经优化的制备条件为:海藻酸钠、壳聚糖及氯化钙的质量分数分别为3%、0.6%及5%,芯壁体积比为1∶2,制备的载药微球形状规整,成球性良好,粒径约0.7 mm,载药量31.65%,包埋率83.81%;红外光谱分析显示,芯壁材料之间除氢键外,没有发生化学作用。所制备的阿维菌素微球在土壤中具有缓释特性,42 h累积释药率达到82.06%,之后药物释放减缓。药物释放特性符合Riger-Peppas模型,释放机理为Fick扩散。     

氟脲嘧啶白蛋白缓释微球的制备及体外性质的研究

目的:探讨以牛血清白蛋白为载体的氟脲嘧啶白蛋白微球的最佳制备方法及有关体外性质。方法:使用均匀设计法筛选制备氟脲嘧啶白蛋白微球(FU-BM)。以七个因素十二个水平,优化出最佳工艺。并对FU-BM体外性质进行研究。结果:制得FU-BM外观呈米黄色,粉末状,球形圆整,粒径分布在1~10μm。载药量为(11.37±0.42)%,包封率(62.58±3.24)%。结论:氟脲嘧啶白蛋白微球具有缓释作用。     

奥曲肽长效生物可降解微球的制备工艺研究

运用复乳法制备奥曲肽PLGA长效生物可降解微球,并用正交法优化微球制备工艺。利用HPLC、显微镜、激光粒度仪等对微球进行综合质量研究。结果表明,复乳法制备奥曲肽微球的最佳工艺参数为:内水相药物与中油相PLGA的质量比为1∶5,中油相PLGA的浓度为10%,外水相乳化剂为1%的22 000分子量聚乙烯(PVA)水溶液,中油相与外水相的体积比不小于1∶50,复乳化采用机械搅拌法,搅拌速度为1 200 r/min。在该工艺条件下制得的微球,包封率为35.1%,载药量为2.98%,平均粒径为26.3μm,微球外观圆整,形态良好。     

阿司匹林载药淀粉微球吸附性能的研究

以可溶性淀粉为原料,研究了淀粉微球在反相悬浮体系中对阿司匹林的吸附作用。探讨了交联剂用量、引发剂用量、反应时间及搅拌速度对微球药物吸附量的影响,并考察其体外释放情况。结果表明：当交联剂用量为12g/L,引发剂用量为3g/L时,60℃下中速搅拌2.0h,淀粉微球对阿司匹林有较大吸附作用。在酸性条件下,阿司匹林淀粉微球在8h内有较好释放,交联剂用量对释药速率有较大影响。     

pH敏感聚合物微球的制备及其性能研究

通过原位聚合的方法制备了生物相容的、具有环境响应特性核壳型羟乙基纤维素／聚甲基丙烯酸(HEC／PMAA)聚合物微球。采用动态光散射法和荧光光谱法研究了HEC／PMAA聚合物微球的形成机理;采用红外光谱(FTIR)分析了微球中分子间相互作用;利用TEM观察了HEC／PMAA微球的形貌;考察了HEC／PMAA微球的pH敏感性能。     

Thermoresponsive hollow magnetic microspheres with hyperthermia and controlled release properties

Thermoresponsive hollow magnetic microspheres consisting of a hollow magnetic core, a carbon shell, and a smart polymer layer are presented in this article. A carbon nanomaterial was used as a steric stabilizer for Fe₃O₄ nanoparticles and a supporter for polymer. The thermoresponsive monomer, N‐isopropyl acrylamide, was grafted on the carbon‐encapsulate hollows by surface radical polymerization. The experimental results indicate that the composites had a phase‐transition temperature around 43°C and a saturation magnetization of 56.9 emu/g; this showed apparent thermosensitivity and magnetism. The performances in hyperthermia evaluated by an inductive magnetic field showed that the hybrid microspheres had a specific absorption rate of 240 W/g. The model drug, 5‐fluorouracil, was loaded in and released from the microspheres with different release rates at 35 and 50°C. This demonstrated that the as‐synthesized microspheres had a thermotriggered release ability and would be a good drug carrier in the biomedical field. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42617.     

磷系阻燃聚酯纤维的制备与性能研究

本工作在制备磷系共聚/共混型聚酯的基础上,对磷系阻燃聚酯纤维进行了纺丝试验研究,并通过大角X衍射、声速和动态力学测试等手段对含磷阻燃PET纤维的结构性能进行了探讨。试验表明,含磷阻燃PET纤维的强度能达到2.8～3.0cN/dtex,LOI值达到32.5～34,但相应的结晶度和取向度低于常规PET纤维。     

Elaboration of microspheres and coated microspheres for the controlled release of the herbicide 2,4-D

Summary Controlled release systems loaded with 2,4-D were prepared by double encapsulation using solvent evaporation technique followed by the complex coacervation method. The production of these systems was aimed at modifying the release rate of the active agent and at reducing the herbicide risks by dermal contact. The coated microspheres are composed of Ethylcellulose or Cellulose acetate butyrate butyryle as microsphere matrix and with Gelatin–Arabic gum complex as envelope. The microparticles were characterized by scanning electron microscopy and the size and size distribution were determined. The drug release from the coated microspheres was established in water at 25 °C and it was compared with those of microspheres without envelope. The release mechanism of the active agent from microspheres was investigated according to Fick’s law. So the present paper completes the characterization of microspheres by the calcul of the effective diffusion coefficients.     

Investigation on preparation and protein release of biodegradable polymer microspheres as drug‐delivery system

Among the different approaches to achieve protein delivery, the use of polymers, especially biodegraded, holds great promise. This work aimed to study the preparation and protein release of a novel drug‐delivery system based on human serum albumin (HSA) encapsulated into biodegradable polymer microspheres. The microspheres containing HSA were elaborated by the solvent‐extraction method based on the formation of multiple w/o/w emulsion. The encapsulation efficiency (E.E.) of HSA was determined by the CBB method. Alginate/alginate and calcium chloride was added into an internal aqueous phase to investigate the protein loading efficiency, protein stability, and in vitro release profiles. Microspheres were characterized in terms of their morphology, size distribution, loading efficiency, and in vitro protein release. SDS–PAGE results showed that HSA kept its structural integrity during the encapsulation and release procedure. In vitro studies indicated that the microspheres with alginate added in the internal aqueous phase had a smaller extent of burst release. In conclusion, the work presents a new approach for macromolecular drugs (such as protein drugs, vaccines, and peptide drugs) delivery. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 778–784, 2002; DOI 10.1002/app.10327     

空心微球的制备及应用进展

对国内外制备空心微球的方法(自组装法,模板法,乳液法等)进行了概述;同时评述了空心微球作为功能材料在不同领域中的最新研究进展。     

Effect of preparation conditions on the properties of microspheres prepared using an emulsion-solvent extraction process

Methylaluminoxane microspheres were prepared using a hydrocarbon-in-perfluorocarbon-emulsion solvent extraction process. The effect of the preparation conditions on the size of the microspheres was investigated. As expected, the size of the microspheres decreased with increasing stirring speed. At low surfactant concentrations the size of the microspheres was independent of the surfactant concentration. However, the size of the microspheres decreased as the surfactant concentration was further increased. The size of the microspheres was not only affected by the surfactant concentration but also by the volume ratio of the dispersed phase to the continuous phase. At a low volume ratio of the phases the effect of the surfactant on the size of the microspheres was larger than the effect of the increased volume ratio of the phases. At high volume ratios of the phases the effect of the volume ratio of phases on the size of the microspheres became more significant than the effect of the surfactant. A slow solidification increased the formation of non-spherical microspheres.     

热膨胀微胶囊的制备研究

以丙烯腈(AN)、甲基丙烯酸甲酯(MMA)、丙烯酸甲酯(MA)为单体,采用悬浮聚合的方法制备了热膨胀微胶囊。通过热膨胀仪、扫描电子显微镜、热重分析仪等分析方法,考察了单体配比、发泡剂种类、反应压力、异戊烷用量和粒径大小对微胶囊发泡性能的影响。结果表明,当丙烯腈(AN)、甲基丙烯酸甲酯(MMA)、丙烯酸甲酯(MA)的摩尔比为12:4:1时,微胶囊的膨胀性能最佳;异戊烷、正己烷、异辛烷作为发泡剂,所制备微胶囊发泡性能优异;异戊烷作为发泡剂时,需加压反应,当加入量为30%时,膨胀性能最佳。