聚乳酸微胶囊的层层自组装及表征

以碳酸钠和氯化钙为原料制备的碳酸钙微球为模板,采用层层自组装的方法,将左旋聚乳酸(PLLA)和右旋聚乳酸(PDLA)逐层组装在碳酸钙微球上,然后用乙二胺四乙酸二钠(EDTA)去除模板碳酸钙后成功制备了聚乳酸中空微胶囊,并采用扫描电镜、原子力显微镜、透射电子显微镜、激光共聚焦显微镜、差示扫描量热仪和广角X射线衍射仪对微胶囊进行初步表征。结果表明,微胶囊层形成的层间驱动力为聚乳酸异构体之间的立构复合作用,微胶囊呈现经典的褶皱状,囊壁厚度约为90~100nm,内部为空腔结构,囊壁允许小分子物质透过,在载药缓释领域具有很好的应用前景。     

界面聚合法制备十二醇相变微胶囊的工艺及性能

为了解决低温相变材料稳定性差、不易储存运输等问题,以六亚甲基二异氰酸酯(HDI)、1,3-丙二胺为壁材单体,以相变温度较低、相变潜热较高的十二醇为芯材,通过界面聚合法制备了低温相变微胶囊.由于十二醇具有反应活性,本工作研究了不同结构异氰酸酯作为壁材单体的适应性,探索了1,3-丙二胺水溶液的pH值对微胶囊形貌的影响.在1,3-丙二胺水溶液的pH值为9.0的情况下,制备的微胶囊粒径约2.0μm,芯材载量为79.8％,熔融温度为24.47℃,熔融热焓为142.3 J/g.相比于原位聚合法,界面聚合法制备的微胶囊有更好的致密性,在甲醇中的渗透率下降了40％,提高了十二醇相变材料的稳定性,有效改善了其泄漏、储存运输等方面的问题.     

层层自组装法制备肝素微囊及其性能研究

以海藻酸钙微核为模板,采用带正电荷的聚稀丙基铵盐酸盐(PAH)和带负电荷的肝素钠(HEP),通过层层自组装(Layer-by-layer,LbL)技术构建具有多层膜结构和抗凝血活性的药物微囊.采用荧光倒置显微镜、SEM、动态光散射仪、Zeta电位仪和抗凝血仪等进行表征.结果表明,制备的海藻酸钙微核粒径约为1.5μm,尺寸均匀、分散性佳;以ALG为模板制得的LbL微囊具备典型的核壳式结构;Zeta电位检测表明,随包膜层数的增加,微囊的电位呈正负交替的变化趋势;通过体外凝血时间(PT、APtt、TT)检测微囊抗凝血活性,比较了分别以PAH和HEP作为最外层时的生物活性,其中以HEP为最外层的显著增强了材料的抗凝血性能,同时随着组装层数的增加,也提高了微囊的抗凝血性能.     

花色苷微胶囊的制备及其理化性质研究

目的 针对花色苷易降解不稳定等问题,采用复合壁材对花色苷进行微胶囊化处理以提高其加工稳定性。方法 以蓝莓花色苷为芯材,改性玉米淀粉/明胶作为复合壁材,利用真空冷冻干燥法制备花色苷微胶囊。以花色苷的包埋率为评价指标,考察壁芯比、改性玉米淀粉/明胶的质量比、包埋温度和包埋时间对包埋率的影响。通过傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)、热重分析(TGA)对其进行表征并测定其抗氧化性。结果 当壁芯比为8∶1、改性玉米淀粉/明胶质量比为1∶2、包埋温度为60 ℃、包埋时间为40 min时,制备的微胶囊具有更高的包埋率。FTIR结果表明花色苷被成功地包埋。制备的微胶囊呈不规则的片层结构,整体表现光滑,表面无团聚现象。微胶囊化后的花色苷热稳定性、抗氧化能力均有所提高。结论 所制备的花色苷微胶囊具有热稳定性高、抗氧化性强、壁材间相容性好等特点,在食品工业化应用方面具有巨大潜力。     

三氯蔗糖微胶囊的制备与工艺优化

为延缓三氯蔗糖甜味特性,采用微胶囊技术对三氯蔗糖进行包埋处理。选择大豆分离蛋白和海藻酸钠为壁材,三氯蔗糖为芯材,采用复合凝聚法制备三氯蔗糖微胶囊。以微胶囊产率为评价指标,利用单因素试验和响应面优化法确定最佳制备条件,并对其形态等进行表征。研究结果表明,微胶囊的最佳制备工艺：复凝聚pH值为3.01,芯壁质量比为1.27,大豆分离蛋白和海藻酸钠的质量比为3.01,壁材质量浓度为0.0304 g/mL。按此工艺条件制备的三氯蔗糖微胶囊呈完整球形,表面光滑平整,粒径约为50μm,产率可达75.19%。     

Preparation of Polymeric Microcapsules: Formulation Studies

Air-filled microcapsules were prepared by freeze-drying different oil-in-water emulsions containing biodegradable polyester as the wall-forming material. The aim of this work was to find an acceptable formulation with respect to the microcapsule suspension and the stability of the emulsion during the production process. The influence of various formulation parameters (concentrations of mannitol, polymer, and surfactant; pH; oil-in-water phase ratio) was investigated in a factorial design. The results were treated by ordinary least-square (OLS) regression and partial least-square regression (PLSR). In a previous work, air-filled microcapsules were successfully made using human serum albumin as the surfactant in the emulsion . In the present work, a new block copolymer based on poly(ethylene glycol) (PEG) was implemented as the surfactant to replace human serum albumin. It was found that the new block copolymer is a suitable replacement for human serum albumin. The concentration of the polymer in water and the concentration of the surfactant in the oil phase and the interaction between these variables had a significant influence on the stability of the emulsion at 60°C. A surfactant concentration of approximately 2% (w/v) in water was necessary when the concentration of the wall-forming polymer was below 5% (w/v) in (-)-camphene. The concentration of the polymer in the oil phase influenced the yield, measured as the volume concentration of particles in suspension per milligram of polymer added and as acoustic effect per milligram of polymer. Low levels of polymer concentration in (-)-camphene (<5% w/v) gave the highest yield. Excess polymer in the oil phase did not form microcapsules, but precipitated in the suspension or was included in the wall of the microcapsules. Addition of mannitol protected the microcapsules from being destroyed during freeze-drying and resulted in freeze-dried products with few cracks, little shrinkage, and higher suspension yield.     

纳米微球在生物医药领域的应用

纳米微球技术是近年来在生物技术应用中最为热门的前沿技术之一。各种微球产品的应用给生物技术研究带来了新的课题,形成了众多新的研究领域。从生物技术的发展现状和未来方向出发,对纳米微球在生物医药研究中几个重要领域的应用前案进行了综述。     

冷冻诱导相分离法制备大孔羧甲基壳聚糖基高吸水树脂

探索了冷冻诱导相分离法制备具有大孔结构的高吸水性树脂的方法。将羧甲基壳聚糖基高吸水树脂在水中溶胀并冷冻后,通过冷冻干燥的方法制得了具有大孔结构的高吸水树脂,这类树脂具有较快的吸水速率。研究了凝胶浓度、预冻温度、溶胀时间和明胶含量等反应条件对所制备树脂结构及溶胀动力学的影响。     

石蜡微胶囊的制备及改性研究进展

目的概述石蜡相变材料微胶囊在相变温控、能量利用和热交换等主要应用领域内的研究状况,并对未来的应用与发展进行展望,旨在为石蜡微胶囊的改性研究提供一定思路。方法通过分析和总结近年来国内外有关石蜡微胶囊材料的文献,主要从石蜡微胶囊材料的制备方法和改性手段等方面对目前的石蜡微胶囊材料进行综述。结果石蜡微胶囊的壁材结构和芯材成分对石蜡微胶囊的热性能有非常重要的影响,通过对壁材和芯材的改性,提升了石蜡微胶囊的热性能。结论石蜡微胶囊的改性能够实现更高热性能的目标,达到更多热应用的要求,具有很大的发展潜力,在主要应用领域内能得到更加广泛的应用,但仍存在着一些亟待解决的问题。     

Phenylpropanolamine HCl Microcapsules: Preparation and release studies

Microcapsules of phenylpropanolamine HCL were prepared by three techniques, viz. coacervation-phase separation, air suspension, and pan coating, using different polymers and/or waxes as wall-forming materials.

Formulations showed reasonable dissolution behaviour, viz. microcapsules prepared by air suspension with polymer level of 20% polyvinyl acetate copolymer (PVAC) associated with 40% carnauba wax (II) and microcapsules prepared by pan coating with polymer level of 25% Rodopace^R (III), were evaluated for their absorption rates by demonstrating their toxicities compared to pure grug (I) by the LD₅₀ method. Toxicity assessment showed close agreement between the increase in lethal dose and the decrease in dissolution rate and revealed that Formula III has more prolonged action than Formulae II and I.     

含微胶囊的抗菌淀粉膜制备工艺及性能研究

目的研究一种含微胶囊的抗菌淀粉膜制备工艺,并对其性能进行评价。方法以淀粉作为成膜基材,加入具有抗菌性的微胶囊,以及明胶、甘油、CaCl_2等助剂,采用流延法制备出含微胶囊的抗菌淀粉膜。将淀粉/甘油/明胶的质量比、微胶囊含量、CaCl_2含量、干燥温度作为影响因素,进行正交试验,选取膜的水溶性、力学性能、抗菌性能作为指标,对其性能进行检测和综合评价。结果当淀粉/甘油/明胶质量比为6∶3∶1,微胶囊质量分数为20%,CaCl_2质量分数为2%,干燥温度为50℃时,薄膜具有较好的综合性能。结论通过加入丁香精油微胶囊,制得的淀粉基薄膜具有抗菌性。     

Drug Release Properties of the Microcapsules of Adriamycin Hydrochloride with Ethylcellulose Prepared by a Phase Separation Technique

Abstract

Adriamycin hydrochloride was microencapsulated with ethylcellulose by a phase separation method to develop a prolonged release dosage form. Polyisobutylene (PIB) was used as a coacervation-inducing agent to control the particle size and drug release rate of the resultant microcapsules. With increasing the concentration of PIB (1 to 3 %) the average diameter of the microcapsules decreased, due to the fact that the microcapsules were discreted to a single microcapsule. At low concentration of PIB, the resultant microcapsules were agglomerated, which resulted in increasing the size. The microcapsules prepared with PIB 2 % prolonged desirably the drug release from the microcapsules. A little size effects of the microcapsules on the drug release rate was found for the microcapsules with PIB 2 % and 3 %.     

Drug Release Properties of the Microcapsules of Adriamycin Hydrochloride with Ethylcellulose Prepared by a Phase Separation Technique

Adriamycin hydrochloride was microencapsulated with ethylcellulose by a phase separation method to develop a prolonged release dosage form. Polyisobutylene (PIB) was used as a coacervation-inducing agent to control the particle size and drug release rate of the resultant microcapsules. With increasing the concentration of PIB (1 to 3 %) the average diameter of the microcapsules decreased, due to the fact that the microcapsules were discreted to a single microcapsule. At low concentration of PIB, the resultant microcapsules were agglomerated, which resulted in increasing the size. The microcapsules prepared with PIB 2 % prolonged desirably the drug release from the microcapsules. A little size effects of the microcapsules on the drug release rate was found for the microcapsules with PIB 2 % and 3 %.     

热敏影像记录材料中显色剂微胶囊的制备

本文主要论述了在一种热敏影像记录材料中,为了得到较低的灰雾和较高的稳定性,对显色剂进行微胶囊化的过程,并就其壁材对显色温度和显色温度范围的影响进行了讨论。     

基于自修复涂料的脲醛树脂微胶囊的制备及其表征

目前,关于包覆桐油的脲醛树脂微胶囊用于自修复涂料的制备研究较少。以桐油为芯材,采用原位聚合方式在桐油表面制备了脲醛树脂微胶囊;采用扫描电镜(SEM)、光学显微镜(OM)、热重分析仪(TGA)以及红外光谱(IR)对胶囊的微观形貌、热稳定性及化学结构进行了表征。结果表明:当预聚合反应p H=8.5,采用OP-10作为乳化剂,其用量为芯材质量的5%,搅拌转速为900 r/min,并控制酸化时间为90 min时,可制得外形完整、尺寸均匀的球形微胶囊,微胶囊表面略粗糙,其直径约为200μm,包封闭率达85.1%,其初始热分解温度为205℃左右。     

核-壳结构微胶囊制备新技术及其应用进展

综述了近年来国外核-壳结构微胶囊新型制备方法及各种方法的特点,归纳了微胶囊结构的表征手段,评述了核-壳结构微胶囊在应用方面的最新研究进展,阐述了微胶囊技术的发展方向.     

异噻唑啉酮微胶囊的制备表征及释放行为

以二异氰酸酯(TDI)、聚乙二醇4000(PEG)、二羟甲基丙酸(DMPA)和三乙胺(TEA)为原料,制备可水乳化的聚氨酯(WPU).以合成的WPU为囊壁、以异噻唑啉酮衍生物(Sea-nine 211)为囊芯,通过乳化自组装得到防污剂Sea-nine 211微胶囊,用红外光谱、粒径分布和扫描电镜对胶囊进行表征,并采用分...     

白云石碳化制备碱式碳酸镁的新钙镁分离方法

以白云石碳化法为基本方法,在碳化过程中加入添加剂乙酰丙酮,并控制体系的pH值,得到了一种改良的钙镁分离方法,制备出高纯碱式碳酸镁。通过单因素实验,研究了煅白消化条件、精镁乳液碳化条件对消化、碳化效率和产品纯度的影响。结果表明,最佳的实验条件为:消化时间40min、消化温度50℃、消化液固比50∶1;碳化至pH值为10时加入添加剂乙酰丙酮(HAA),且加入量为0.005~0.020mol/L,抽滤pH值为8.5。得到的碱式碳酸镁产品的化学成分为:MgO41.00%,CaO0.63%,Fe≤0.05%。     

广藿香油缓释微胶囊的制备及其性能分析

以广藿香油为芯材,壳聚糖和阿拉伯胶为壁材,采用复凝聚法对广藿香油进行包埋,制备广藿香油微胶囊。利用扫描电子显微镜、激光粒度仪、红外光谱和紫外光谱等分析方法研究各因素对微胶囊形成的影响。确定制备广藿香油微胶囊的最佳条件:采用中低粘度的壳聚糖,壳聚糖浓度为0.5%,阿拉伯胶浓度为4%,芯壁比为1∶2,复凝聚pH值为4.5,搅拌转速为2000r/min。红外光谱分析表明广藿香油包埋成功,其载药量和包封率分别为20.75%和67.2%。微胶囊缓释性能测试结果表明微胶囊具有良好的缓释效果,在25℃条件下,微胶囊释放150h后,累计释放率为33%,即微胶囊保留率为67%。