酶响应型捏合淀粉药物载体的制备和性能

采用机械捏合的方法制备了不同抗消化性能的捏合淀粉基载体材料。利用扫描电子显微技术(SEM)、X射线衍射技术(XRD)和体外模拟人体消化试验(In-Vitro)对捏合淀粉的颗粒形貌、结晶结构和在人体上消化道中的消化性能进行了考察。发现随着抗消化性能的降低,淀粉颗粒的破损程度越大,淀粉结晶结构结晶形态由B型向V型转变,消化速度增大。同时以胰酶为模型药物,考察了捏合淀粉对药物的体外释放性能。结果显示,不同抗消化性能的捏合淀粉可望作为不同消化道靶向要求的药物载体材料。     

天然多糖类化合物在口服结肠靶向给药系统中的应用进展

天然多糖类化合物是口服结肠靶向给药系统载体的一个研究热点.简要综述了果胶、壳聚糖、魔芋胶、环糊精等天然多糖类化合物在口服结肠靶向给药系统的应用进展,并展望了其发展趋势.     

金属-有机骨架用于各类药物的控释载体

新型控释药物直接作用于靶细胞,提高药理效率、减小毒副作用,已成为一种极具潜力的药疗方法。与一般药物控释载体相比,金属-有机骨架材料(metal-organic frameworks,MOFs)的优势明显,将其颗粒尺寸降至纳米级后性能更为优异,能同时兼顾药物负载量、目标靶向性、表面特性改善和生物相容性等特性。目前,已有较多类药物吸附在MOFs上的研究报道,主要包括抗癌药物、抗病毒药物及消炎药物。介绍了MOFs的毒性及其发展过程,详细阐述了MOFs对于各类药物的吸附-释放情况,并对此领域的研究和发展进行总结和展望,以期对MOFs作为药物控释载体的应用有比较全面的认识。     

纳米药物载体在医药领域的应用概述

由于纳米药物载体粒径比毛细血管通路远远要小,且具有降低药物毒副作用、提高药物稳定性、缓释控释药物和药物靶向释放等优点,其在医药领域的应用极为广泛。本文简述了纳米药物的载体系统及其在癌症治疗、细胞内靶向给药、定量给药等方面的应用概况。     

介孔氧化硅纳米粒子对药物装载和可控释放的研究进展

近年来,介孔氧化硅纳米粒子(MSN)以其均一的孔道结构、高比表面积、较大的孔容量等优良性质,被广泛应用于药物传递系统。与传统载药系统相比,MSN展示了更高的药物负载量、可控的药物控释性能、可设计的靶向特性、良好的生物安全性等优势。本文通过对MSN对药物的负载机理、药物控释机理等方面的介绍,对MSN在药物传递系统中的应用加以综述。     

生物可吸收储存式药物控释载体制备研究

针对骨科疾病治疗中传统的用药方式存在的问题,研究制备了一种生物可吸收靶向式药物控释载体。首先在体外模拟天然骨的生物矿化过程,利用材料的自组装机制合成了羟基磷灰石／胶原类骨仿生复合材料,再采用热致分相／非溶剂抽提成孔技术进一步与聚乳酸复合制备了三维多孔储存式药物控释载体。通过对材料的表征和模型化合物控释实验,结果显示羟基磷灰石／胶原复合材料与天然骨类似,羟基磷灰石／胶原／聚乳酸储存式载体能达到控制释放的目的。     

磁性交联双醛淀粉微球的制备及表征

提出了一步包埋法(无需表面活性剂)磁性交联双醛淀粉微球,并对其结构、性能进行了测试和表征.以木薯淀粉为原料,高碘酸钠为氧化剂,采用包埋法制备磁性交联双醛淀粉微球,并利用正交实验确定其最佳制备条件为:淀粉用量3.0g,搅拌速度1200r/min,氧化时间2h,氧化温度40℃,高碘酸钠浓度10mmol/L且质量与淀粉用量相当,Fe3 与Fe2 摩尔比为1∶1.经结构表征及性能测试表明,磁性交联双醛淀粉微球醛基平均含量为3.0537mmol/g,Fe3O4%为62.73%,粒径小,耐酸性能良好,具有核壳式结构,为该微球作为靶向药物的载体奠定了良好的基础.     

磁性水凝胶作为药物载体的应用研究进展

磁性水凝胶是一类同时具有磁性材料、高分子材料及水凝胶的性质特点的无机/有机复合材料。因具有优良的磁学性能及生物相容性,其作为新一代的药物载体可以实现磁响应、磁靶向及磁热疗等功能,在药物控制释放领域具有广阔的应用前景。对磁性水凝胶的制备方法及其在药物载体领域的研究情况进行了综述,详细介绍了磁性水凝胶作为药物载体的两种药物释放机理(ON/OFF模型及热敏释放原理),及其在磁靶向药物控释、磁热疗和磁共振成像方面的应用研究现状。     

水难溶性药物的载体材料研究进展

水难溶性药物因其在水中溶解度小使得药物的临床应用受到限制.将水难溶性药物通过某些载体包裹,是对水难溶性药物进行增溶的一种行之有效的方法.综述了水难溶性药物载体材料的研究进展,并总结了各种载体材料的优缺点.针对普遍存在的增溶效果不理想的问题,指出了几种载体未来的发展方向.表面活性剂胶束因其自身的毒性而逐渐被其它载体材料取代.环糊精和聚合物胶束具有广阔的发展前景.尽管脂质体作为水难溶性药物载体存在不足之处,但其可用作水溶性药物的载体或者制备成主动靶向制剂(例如单克隆抗体导向的脂质体)、物理化学靶向制剂(例如磁靶向脂质体),仍具有巨大的研究价值和发展空间.     

高取代度阳离子淀粉的制备与应用研究进展

综述了国内外高取代度阳离子淀粉的制备方法,包括湿法、干法、半干法的合成工艺,以及高取代度阳离子淀粉在造纸、纺织、废水处理等方面的应用研究进展,指出阳离子淀粉正越来越广泛地用于实验室研究,其在蛋白质分析、药物载体、石油采收方面的应用在逐步发展中,阳离子淀粉的应用得到了进一步的推广.     

Resistant starch as a carrier for oral colon-targeting drug matrix system

In this study, a novel tablet of protein drug matrix for colon targeting was developed using resistant starch as a carrier prepared by pre-gelatinization and cross-linking of starch. The effects of pre-gelatinization and cross-linking on the swelling and enzymatic degradation of maize starch as well as the release rate of drug from the matrix tablets were examined. Cross-linked pre-gelatinized maize starches were prepared by double modification of pre-gelatinization and cross-linked with POCl₃, and bovine serum albumin was used as a model drug. For in vitro drug release assays, the resistant starch matrix tablets were incubated in simulated gastric fluid, simulated intestinal fluid and simulated colonic fluid, respectively. The content of resistant starch and swelling property of maize starch were increased by pre-gelatinization and cross-linking, which retarded its enzymatic degradation. Drug release studies have shown that the matrix tablets of cross-linked pre-gelatinized maize starch could delivery the drug to the colon. These results indicate that the resistant starch carrier prepared by pre-gelatinization and cross-linking can be used for a potential drug delivery carrier for colon-targeting drug matrix delivery system.     

Studies of guar gum compression-coated 5-aminosalicylic acid tablets for colon-specific drug delivery

The aim of this study was to develop colon-specific delivery systems for 5-aminosalicylic acid (5-ASA) using guar gum as a carrier. Core tablets containing 5-ASA were prepared by wet granulation with starch paste and were compression coated with coating formulations containing different quantities of guar gum (300, 200, 150, and 125 mg). In vitro drug release studies were carried out in simulated gastric and intestinal fluids and in pH 6.8 buffer containing rat cecal contents. The application of 175 mg of coating formulation containing 150 mg of guar gum over 5-ASA core tablets resulted in the release of less than 2% drug in simulated gastric and intestinal fluids and about 93% of 5-ASA in pH 6.8 buffer containing rat cecal contents. Differential scanning calorimetric (DSC) studies showed the absence of any interaction between 5-ASA and the excipients on storage at 45°C for 12 weeks. The study confirmed that selective delivery of 5-ASA to the colon can be achieved using guar gum as a carrier in the form of a compression coating over the drug core.     

Studies of Guar Gum Compression-Coated 5-Aminosalicylic Acid Tablets for Colon-Specific Drug Delivery

The aim of this study was to develop colon-specific delivery systems for 5-aminosalicylic acid (5-ASA) using guar gum as a carrier. Core tablets containing 5-ASA were prepared by wet granulation with starch paste and were compression coated with coating formulations containing different quantities of guar gum (300, 200, 150, and 125 mg). In vitro drug release studies were carried out in simulated gastric and intestinal fluids and in pH 6.8 buffer containing rat cecal contents. The application of 175 mg of coating formulation containing 150 mg of guar gum over 5-ASA core tablets resulted in the release of less than 2% drug in simulated gastric and intestinal fluids and about 93% of 5-ASA in pH 6.8 buffer containing rat cecal contents. Differential scanning calorimetric (DSC) studies showed the absence of any interaction between 5-ASA and the excipients on storage at 45°C for 12 weeks. The study confirmed that selective delivery of 5-ASA to the colon can be achieved using guar gum as a carrier in the form of a compression coating over the drug core.     

Development of a novel starch-derived porous silica monolith for enhancing the dissolution rate of poorly water soluble drug

A novel starch-derived porous silica monolith (PSM) and porous starch foam (PSF) were developed as a carrier in order to improve the dissolution of lovastatin. PSM was prepared by the starch gel template method and PSF was prepared by the solvent exchange method. The morphology and structure of PSM and PSF were characterized by scanning electron microscopy (SEM) and nitrogen adsorption/desorption analysis. Lovastatin was loaded into PSM and PSF by immersion/solvent evaporation. Nano-pore spatial confinement effect on the drug dissolution was systematically studied by SEM, Fourier transform infrared spectroscopy (FTIR), thermogravametric analysis (TGA), x-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and in-vitro drug dissolution studies. Lovastatin adsorbed in PSM was amorphous and lovastatin absorbed on PSF was partially present as microcrystal in the pores of PSF and partially in crystalline form distributed on the surface of PSF. PSM and PSF allowed immediate release of lovastatin and enhanced the dissolution rate. These results provide important information about the mechanism of drug adsorption and release. Accordingly, PSM and PSF have a promising future as a vehicle for the oral delivery of poorly water soluble drugs. Moreover, the effect of PSM is better than that of PSF.     

聚羟基乙酸接枝淀粉共聚物的合成和性能

以乙交酯和淀粉为原料,三乙胺为催化剂,在二甲基亚砜介质中合成了聚羟基乙酸接枝淀粉共聚物。讨论了原料配比和反应时间对共聚物接枝率(G)、接枝效率(E)和单体转化率(C)的影响。采用核磁共振谱仪(1H-NM R)、傅立叶变换红外光谱仪(FT-IR)、X射线粉末(多晶)衍射仪(XRD)、差式扫描量热仪(DSC)以及体外降解试验,研究了接枝共聚物的结构和性能。实验结果表明,将乙交酯单体和淀粉接枝共聚,可以得到一类新的可降解聚合物。     

Calcium pectinate capsules for colon-specific drug delivery

The calcium pectinate (CaP) capsule, a novel, colon-specific delivery system, was designed and developed using 5-fluorouracil (5-FU) as a model drug. Technically, CaP capsules were prepared by dipping a glass or stainless steel rod successively into pectin and calcium chloride solutions, followed by subsequent air-drying and coating. In vitro studies showed that the release of 5-FU from CaP capsules markedly increased in the presence of rat cecal contents, and the release characteristic was mainly associated with some capsule parameters such as calcium content, shell thickness, and coat amount. Gamma scintigraphic studies demonstrated that CaP capsules could pass through the stomach and small intestine intact and could release drug in colon. The 5-FU releasing characteristics acquired both from in vitro biomimic dissolution experiments and from healthy volunteers indicated that the newly developed CaP capsule possessed the ideal colon-specific drug delivery characteristic.     

Calcium Pectinate Capsules for Colon-Specific Drug Delivery

The calcium pectinate (CaP) capsule, a novel, colon-specific delivery system, was designed and developed using 5-fluorouracil (5-FU) as a model drug. Technically, CaP capsules were prepared by dipping a glass or stainless steel rod successively into pectin and calcium chloride solutions, followed by subsequent air-drying and coating. In vitro studies showed that the release of 5-FU from CaP capsules markedly increased in the presence of rat cecal contents, and the release characteristic was mainly associated with some capsule parameters such as calcium content, shell thickness, and coat amount. Gamma scintigraphic studies demonstrated that CaP capsules could pass through the stomach and small intestine intact and could release drug in colon. The 5-FU releasing characteristics acquired both from in vitro biomimic dissolution experiments and from healthy volunteers indicated that the newly developed CaP capsule possessed the ideal colon-specific drug delivery characteristic.     

Preparation and Characterization of Coacervate Microcapsules for the Delivery of Antimicrobial Oyster Peptides

Oyster peptides-loaded alginate/chitosan/starch microcapsules were prepared using external gelation method and internal emulsion gelation method. The solution of oyster peptides complexes was encapsulated into the microcapsules, which endowed the microcapsules with intestine passive targeting properties. The swelling behavior, encapsulation efficiency, and release behavior of oyster peptides from the microcapsules at different pH values were investigated. The microcapsules exhibited sustained release of the peptides in intestinal medium, and the release rate could be regulated by the pH value: in simulated gastric fluid, the release rate was greatly decreased, and in simulated body fluid and intestinal fluid, the microcapsules exhibited a sustained release in 24 h with different release rates. The microspheres were characterized by Fourier transform infrared. The results suggested that the alginate/chitosan/starch microcapsules could be a suitable copolymeric carrier system for intestinal protein or peptides delivery in the intestine.     

卵磷脂/果胶锌复合凝胶球的制备及性能

采用滴制法, 以吲哚美辛(IDM)为模型药物, 皂化高甲氧化苹果果胶为骨架材料, 氯化锌为交联剂, 并复合卵磷脂(PC)制成吲哚美辛卵磷脂/果胶锌复合凝胶球。针对工艺参数对复合凝胶球粒径、粒重、载药量与包封率以及体外释药性能的影响进行了讨论。凝胶球均成均匀球形, 粒径1.13~1.42 mm, 粒重1.13~2.32 mg, 包封率范围70.72%~94.76%, 载药量范围5.84%~13.54%。同时实验结果表明, 卵磷脂的加入比例、药胶比(吲哚美辛与果胶的质量比)和皂化用NaOH浓度对复合凝胶球的形态、载药及释药性能均有明显影响。其中, 卵磷脂的加入使复合凝胶球载药性能和在模拟肠液中的缓释性能明显提高, 当卵磷脂与果胶的质量比为5:4, 皂化用NaOH浓度为30 g/L, 药胶质量比1:4时, 复合凝胶球在肠模拟液中8 h累计释药率为8.93%。稳定性实验结果表明, 在高温和光照的条件下放置, 卵磷脂/果胶锌复合凝胶球比原药及果胶锌凝胶球具有更好的稳定性, 显示出卵磷脂对果胶锌复合凝胶球在结肠定位给药系统的明显改善作用。