重组α-2b干扰素缓释微囊制备工艺及体外释药过程研究

以聚乳酸乙醇酸(PLGA)为囊材,对制备a-2b干扰素缓释微囊的工艺条件进行优化,研究了不同PLGA浓度、搅拌速度和搅拌时间对缓释微囊粒径分布、载药量、包封率和体外释药过程的影响。结果显示,在PLGA浓度为0.7gmL-1,搅拌速度2100rmin-1,搅拌时间4min条件下,制备的微囊平均粒径为2.8721m ,表面平滑、形态规整且不聚集,载药量为3.91%,包封率为85.8%,体外可连续释药10天,没有明显突释效应,释药量达93.3%,符合临床药用标准。     

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。     

恩诺沙星复合掩味微囊的制备及体外评价

采取固体分散技术联合微囊技术制备兽用恩诺沙星复合掩味微囊,考察了其掩味效果;以其在模拟口腔液中的释放度、载药量和包封率为指标,利用单因素实验和正交实验优化制备工艺.结果表明,复合微囊最优制备条件为:海藻酸钠溶液浓度15 g/L,滴加针头孔径1.0 mm,CaCl_2浓度100 g/L,固化时间10 min.该条件下所得复合微囊外观形态良好,载药量为20.3%,包封率为89.8%,平均粒径为273.67μm;微囊在模拟口腔液中30 s的释放度小于猪对恩诺沙星的苦味阈值,有较好的掩味效果.     

靶向性紫杉醇纳米胶束的制备及体外评价

为了增加紫杉醇溶解度和稳定性,采用薄膜分散法制备紫杉醇纳米胶束;采用粒径测定仪测定粒径和PDI;采用UV法测定药物的含量,计算载药量和包封率;采用膜透析法对载药聚合物胶束的体外释药进行考察。本研究制备的纳米胶束粒径分布均匀,平均粒径为(64.34±1.83)nm,包封率大于85%;紫杉醇纳米胶束体外释放显示了良好的缓释特性。本研究制备的紫杉醇纳米胶束制备工艺操作简单,制备得到载药胶束的粒径较小且分布均匀,包封率、载药量较高。     

微通道内PCL-PEG-PCL载姜黄素纳米粒的制备及体外释药评价

目的:制备姜黄素载药纳米粒。方法:开环聚合法制备PCL-PEG-PCL三嵌段聚合物,微通道界面沉淀法制备姜黄素载药纳米粒,透射电镜观察纳米粒子形貌特征,动态光散射(DLS)测定粒径及其分布,HPLC测定纳米粒子的包封率和载药量,同时考察其体外释药性能。结论:姜黄素纳米粒平均粒径200 nm左右,粒径分布较窄,平均包封率(92.76±0.58)%,载药量(10.76±1.17)%,TEM观察纳米粒呈规则球形,10 d体外累积释药量76%。     

利巴韦林-壳聚糖微粒的制备及载药特性

以利巴韦林为模型药物制备了利巴韦林-壳聚糖微粒,测定了微粒的粒径分布,利用傅里叶变换红外光谱分析了微粒的结构,并考察了微粒的载药和释药特性。结果显示,所制备微粒的粒径可为纳米级;作为交联剂的三聚磷酸钠与壳聚糖的-NH3+基团发生了离子交联,并且利巴韦林被包埋在微粒内部和吸附在其表面。微粒具有较好的载药和缓释性能,最佳的包封率和载药量可达12.8%,在pH=7.4的磷酸缓冲液中可持续释药72h以上。     

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。     

大蒜素/海藻酸钠/明胶/壳聚糖复合微球的制备及性能

以大蒜素为模型药物,采用复凝聚法制备了海藻酸钠/明胶/壳聚糖复合微球,考察了不同条件对微球溶胀性、载药性能和缓释性能等指标的影响。结果表明,明胶和海藻酸钠(质量比为1∶3)为2%,大蒜素投入量与混合胶比为1∶2时,制备的载药微球(DSGCM)外形规则,粒径分布在0.8~0.9mm之间,载药量为24.3%,包封率为69.4%,复合微球具有p H敏感性,在p H=7.4介质中微球溶胀率达到450%,药物释放过程符合Higuchi方程,明胶的加入可以延缓DSGCM复合微球的药物释放性能。     

壳聚糖聚乙烯醇复合载药微球的制备

以壳聚糖(CS)为基质,通过聚乙烯醇(PVA)的引入制备壳聚糖聚乙烯醇复合载体可以分别采用室温和高温酸催化反应两种方法制备出释药性能和结构形态不同的两种复合载药微球Ⅰ和Ⅱ。其中壳聚糖/聚乙烯醇复合载药微球Ⅰ的制备工艺是调节壳聚糖和聚乙烯醇质量比6/5,复合微球Ⅰ的平均粒径1～20μm,载药量13%,LVFX体外12h累积释放80%。而壳聚糖/聚乙烯醇复合载药微球Ⅱ的平均粒径1.69μm,载药量17.1%,LVFX体外6hr基本完全释放。     

膨润土对海藻酸钠/壳聚糖凝胶微球性能的影响

为了得到一种对啶虫脒具有高负载率和良好的缓释性能的农药载体,以膨润土作为吸附剂,利用壳聚糖的成膜性,采用挤出外源凝胶法制备了啶虫脒凝胶微球。并通过FTIR、SEM、TG、溶胀实验和释药实验对其结构、形貌和性能进行表征。结果表明,所制得的凝胶微球的粒径为1.42～1.71 mm,膨润土可提高微球粒径与球形度,使啶虫脒的载药率和包封率分别由原来的4.16%和36.36%提升为4.91%和63.01%。壳聚糖与海藻酸钠通过静电作用形成了聚电解质复合物,辅助了钙离子交联,使啶虫脒的载药率和包封率分别由原来的4.16%和36.36%提升为5.23%和54.29%。膨润土表面含有大量的羟基,与海藻酸钠和壳聚糖形成氢键作用,可有效抑制海藻酸钙的大量溶胀,提高其缓释性能。     

新型负载5-氨基水杨酸微胶囊的制备及其载药效果

采用锐孔/聚合法制备了平均粒径为1.89 mm、负载5-氨基水杨酸(5-ASA)的纤维素硫酸钠(NaCS)-壳聚糖微胶囊,采用Box-Behnken响应面法进行实验设计和分析,考察了内、外水相pH值和NaCS浓度、多聚磷酸钠(PPS)浓度对微胶囊载药量和包封率的影响. 结果表明,内水相pH值对负载5-ASA微胶囊的载药量和包封率起关键作用. 最佳制备条件为内水相pH 4.25,外水相pH 6.0,NaCS浓度14 g/L, PPS浓度5 g/L,该条件下所制微胶囊最大载药量为59.02%,最大包封率为89.96%..     

Preparation of polymeric microcapsules enclosing microbial cells by radical suspension polymerization via water-in-oil-in-water emulsion

Polymeric microcapsules enclosing Saccharomyces cerevisiae were prepared by radical suspension polymerization via water-in-oil-in-water emulsion. Trimethylolpropane trimethacrylate and 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) were used as monomer and radical initiator, respectively. A culture medium with suspended yeast cells, monomer solution with the dissolved radical initiator, and poly(vinyl alcohol) aqueous solution were used as inner aqueous phase, oil phase, and outer aqueous phase, respectively. The influence of microcapsule preparation parameters on the viability of encapsulated cells and encapsulation efficiency was investigated. The radical polymerization process did not cause significant damage to encapsulated yeast cells. Decreased weight ratio of aqueous phase to oil phase resulted in increased encapsulation efficiency of the cells. The diameter of the microcapsules could be controlled by varying the agitation rate.     

膜乳化技术-复乳法制备载药微囊的研究

以乙交酯和丙交酯的无规共聚物(PLGA)做为包埋材料,采用膜乳化技术结合复乳溶剂挥发法制备BSA载药微囊。研究了膜乳化压力、搅拌速度和固化时间对包封率的影响,以及载药微囊的体外释放行为。分析表明,随着膜乳化压力的增加,包封率会不同程度的降低;当搅拌速度大于200 rpm时,搅拌速度的增加也会导致包封率的降低;固化时间为5h时,包封率最高。采用膜乳化技术,可以有效的缓解载药微囊的突释现象,1个月内的累计释放量可以达到80%以上。     

Preparation and Application of Poly(melamine-urea-formaldehyde) Microcapsules Filled with Sulfur

Poly(melamine-urea-formaldehyde) microcapsules containing sulfur were prepared by in-situ polymerization. Several preparation parameters of microcapsules were investigated by analyzing the morphology, particle size and encapsulation efficiency. The morphologies indicated that sodium dodecyl sulfonate (SDS) was a suitable surfactant. The mean diameter of microcapsules decreased with increasing stirring rate and surfactant concentration. The high encapsulation efficiency was achieved by stirring at 300 rpm. The microcapsules were characterized by Fourier Transform Infrared Spectroscope (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The microcapsules were applied in rubber, and the curometer test showed that it prevented blooming and improved the mechanical properties of NBR.     

CS／PLLA／TPP纳米微胶囊的制备及体外释放

主要考察负载雷帕霉素（Rapaymcin,RAPA）的壳聚糖（Chitosan,CS）微球在加入左旋聚乳酸（L—polylactic acid,PLLA）时的载药量,包封率及在不同溶剂中的缓释性能。采用三聚磷酸钠（Sodium tripolyphosphate,TPP）作为离子交联剂,应用离子凝聚法制备CS／PLLA／TPP纳米微胶囊,用透射电镜和粒径分析仪进行了表征。结果表明：离子凝胶法可以得到粒径约300—400nm均匀分散的壳聚糖纳米微胶囊;微胶囊包封率可达84．25％,微胶囊载药量可达30．22％,雷帕霉素在不同溶剂中的缓释性能有很大不同。     

Microencapsulation of capsaicin by the complex coacervation of gelatin,acacia and tannins

With gelatin and acacia as walls and capsaicin as the core substance, microcapsules were prepared through the mixing of two solutions of oppositely charged polymers and were then treated with tannins. The processing factors included the stirring rate and the types and dosages of the surfactants used in the preparation of the microcapsules. The morphology and size distribution of the microcapsules were analyzed with optical microscopy, environmental scanning electron microscopy, and laser particle size analysis. The microcapsules had a mean diameter of 20–30 μm, a maximal drug loading content of 19.84%, and an encapsulation efficiency of 88.21% with a good dispersion, even distribution, and round shape. The influence of the tannins on the morphology and structures of the microcapsules was also investigated, and their interaction mechanism was examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2669–2675, 2004     

Preparation of microcapsules of W/O/W emulsions containing a polysaccharide in the outer aqueous phase by spray‐drying

A water‐in‐oil‐in‐water (W/O/W) multiple emulsion containing a hydrophilic substance, 1,3,6,8‐pyrenetetrasulfonic acid tetrasodium salt (PTSA), and a wall material in its inner and outer aqueous phases, respectively, was prepared by a two‐step emulsification using a rotor/stator homogenizer, and was further homogenized with a high‐pressure homogenizer. Maltodextrin or gum arabic were used as wall materials, and olive oil was used as the oily phase. The high encapsulation efficiency for PTSA (>0.9) was realized. The emulsion was spray‐dried to produce microcapsules of W/O/W type. The efficiencies of the microcapsules prepared with maltodextrin and gum arabic were 0.82 and 0.67, respectively. Stability of the microcapsules was examined at 37 °C and 12%, 33% and 75% relative humidity. Microcapsules prepared with maltodextrin were more stable than those prepared with gum arabic.     

叶面亲和型阿维菌素微胶囊的制备及pH响应性释放性能

为减少农药流失,设计了一种叶面亲和型缓释微胶囊。以甲基丙烯酸甲酯（MMA）接枝改性羧甲基纤维素（CMC）得到羧甲基纤维素-聚甲基丙烯酸甲酯（CMC-g-PMMA）,然后利用自组装负载阿维菌素（AVM）形成载药微胶囊（CMC-g-PMMA@AVM）,通过多巴胺（DA）包覆提高CMC-g-PMMA@AVM的叶面亲和性。采用扫描电镜、红外光谱、热重分析等对其结构和形貌进行表征,研究了微胶囊的载药性能、叶面亲和性及响应释放性能。结果显示,DA/CMC-g-PMMA@AVM为平均粒径126nm的球形粒子,多巴胺的包覆可有效提高微胶囊的载药性能,包封率可达88.56%;增强AVM的叶面亲和性,使其叶面滞留量相对于阿维菌素水乳液提升30.56%;赋予AVM优异的抗紫外光分解性能,强紫外光照射60min后,由AVM水乳液中AVM的残留率14.03%提高到DA/CMC-g-PMMA@AVM中的59.55%。载药微胶囊中药物释放具有pH响应,在pH=5条件下出现爆释,药物释放过程符合Weibull模型,受Fick扩散控制。     

Influence of Poly(L-lactic acid) Molecular Weight on the Encapsulation Efficiency of Urea in Microcapsule Using a Simple Solvent Evaporation Technique

Poly(L-lactic acid) microencapsulated urea was prepared in water-in-oil-in-water (W₁/O/W₂) system by the solvent evaporation technique. The influence of poly(L-lactic acid) molecular weight on the percent loading, encapsulation efficiency, and the microcapsule morphology was studied using poly(L-lactic acid) having different number average molecular weights (M_n). Using the higher M_n, the smoother shell with complete encapsulation microcapsules was formed. Moreover, the percent loading and encapsulation efficiency of urea also increased with the poly(L-lactic acid) molecular weight. At 80,000 g/mol of poly(L-lactic acid), the obtained microcapsule gave the highest both percent loading (32%) and encapsulation efficiency (56%). The urea control release study of the prepared microcapsules was implemented by in vitro testing. The encapsulated urea was gradually released from the microcapsules, approximately 53, 29, and 22% of poly(L-lactic acid) at 3,000, 30,000, and 80,000 g/mol, respectively, for a month. These results presented the possibility of the prepared poly(L-lactic acid) microcapsules-encapsulated urea for urea control release that could be utilized in agricultural applications.