混合药膜缓释体系动力学模型

将化学工程原理应用于药物控制释放建立了应用范围较广的混合药膜缓释体系的动力学模型,讨论了混合药膜的内扩散过程,针对氟尿嘧啶(5-FU)和乙烯-乙烯醇共聚物(EVAL)组成的混合药膜体系进行了实验验证。结果表明本文模型与实验符合良好,并能为Higuchi模型的假设提供理论依据。     

混合药膜体系稳态释放过程的一般分析

推导了平板型混合药膜体系释放过程中界面移动距离与时间的一般关系式。据此研究了药物装填量、释放介质体积、边界层厚度等对释放过程的影响。     

释放介质对混合药膜包膜体系的影响

制得了5－FU／EVAL混合药膜包膜体系,并对该体系中释放介质的pH值和极性对累积释放量的影响进行研究,通过对膜的微观结构的分析,讨论了影响的原因和方式。     

药物控制释放研究及应用

药物控制释放是目前药物学、高分子生物学等多个领域发展的交叉学科。本文主要介绍了药物控制释放体系的种类、机理及高分子材料，并着重介绍了药物控制释放技术在医药上的应用发展现状。     

混合药膜包膜系统释放动力学研究

建立了混合药膜包膜系统释放动力学的简化模型,采有热平衡双重积法获得了模型的解析解。模型预测值与实验值的比较表明,二者吻合较好。     

温敏性聚合物胶束应用于药物控制释放体系的研究进展

当环境温度发生变化时,温敏性双亲嵌段聚合物对这一刺激产生响应,自组装为具有疏水性核/亲水性壳结构的胶束,可作为载体负载活性物质或疏水性药物,具有提高药物利用率、靶向作用、降低毒副作用等特点,可应用于药物控制释放等生物医药领域,具有显著的研究价值和应用前景。介绍了不同类型温敏性聚合物胶束在药物控制释放体系的研究进展。     

含咔唑的聚合物胶束的控制药物释放研究

设计并合成了新型的含有咔唑基团的热响应两亲接枝共聚物PNIPAAm-g-PCbzEA。该共聚物的LCST约为31.5℃,在水溶液中,该共聚物能够自组装形成核-壳型纳米聚合物胶束,聚合物胶束具有近似球状的外形,直径为30~60 nm,并且具有较低的CMC值:12.9 mg/L。该聚合物胶束对抗癌药物甲蝶呤具有较高的包封率,并且显示出了显著的温度控制药物释放行为。     

微凝胶在药物控制释放系统中的应用

药物控制释放系统能弥补传统给药方式在人体血药浓度、药效等方面的不足,并在控制药物释放速率的同时,保持药物有效浓度、降低毒副作用。本文在介绍该释药系统的基础上,以微凝胶结合具体实例阐述说明系统的应用原理及效果,研究发现微凝胶对模型药物具有控制释放作用。     

球形扩散控制体系中药物释放的建模及优化

针对球形扩散控制体系中的药物释放,通过建立数学模型,借鉴反问题求解思路,利用混合Newton-Tikhonov正则化方法,优化体系中初始药物浓度分布以及扩散系数分布,实现不同的目标药物释放。在固定扩散系数条件下,优化了实现拟恒速、速率线性降低及先增后恒速的非线性释放目标的初始药物浓度分布;还优化了不同初始药物浓度分布条件下的体系扩散系数分布,以期达到拟恒速释放。研究表明:通过优化球形基质体系中药物的初始浓度分布或扩散系数分布,体系的药物释放可达到释放的目标要求;通过简单的外层无/少药物负载的初始浓度设计,优化扩散系数的体系可有效解决"突释"问题。     

两亲性嵌段共聚物胶束的制备及对药物的控制释放

两亲性嵌段共聚物在水溶液中通过自组装可以形成以疏水嵌段为核,以亲水嵌段为壳的胶束。其亲水嵌段对胶束起稳定和保护作用,在胶束中通过物理、化学方式载入药物,可以实现对药物的控制释放。简述了嵌段共聚物胶束化的一些基本途径,如利用氢键,离子间相互作用,改变温度,自由基共聚,改变外部环境pH等,探讨了其对模型药物的控制释放。     

A Model of Controlled Release of Polymer-dispersed Drug Systems Containing Regulatory Particles

Abstract

A model of controlled release systems using a polymer matrix with mixtures of dispersed drug particles and regulatory particles is considered. The regulatory particles are fillers that release at a slower rate than the drug and open more paths for the passage of the drug. Mathematical analysis shows that both the drug and regulatory particles have Fickian diffusion behaviors. The use of regulatory particles increases the release rate and can make the system responsive to physiological change.     

Sweet Potato Starch Microparticles as Controlled Drug Release Carriers: Preparation and In Vitro Drug Release

The aim of this study was to investigate the in vitro drug release behavior of sweet potato starch (SPS) microparticles intended for controlled drug delivery applications. Diclofenac sodium (DS) was used as a model drug candidate in the present study. SPS microparticles were prepared using a spray-drying technique by varying the polymer concentration and drug loading. The mean particles size of drug-loaded spray-dried SPS microparticles was between 10.3 and 13.1 µm. The mean particle size increased slightly with increase in the concentration of SPS. The mean particle size of spray-dried SPS microparticles increased from 10.3 to 13.1 µm when the concentration of SPS increased from 2 to 4% w/v. Under the current spray-drying conditions, the percentage yield of spray-dried SPS microparticles did not vary much among the various formulations and it was between 65.2 and 70.1%. The encapsulation efficiencies of SPS microparticles formulations was between 95.1–98.2%, suggesting good encapsulating ability of the SPS polymer by spary drying. Drug release from all the formulations of spray-dried SPS microparticles was controlled over period of 6 h. The cumulative amount of drug release from the spray-dried SPS microparticles decreased with an increase in the concentration of SPS, while it increases as the drug loading is increased. Release of the drug from spray-dried SPS microparticles followed Fick's law of diffusion since a good correlation coefficient (R²) was observed with the Higuchi plots (R² = 0.9928 to 0.9979).     

药物控释体系的研究与控释技术进展

介绍了药物控释体系的种类、作用机理及控释技术最近进展 ,指出发展控释技术意义重大     

Biodegradable Polymer-Based Controlled Release Systems: The Physicochemical Aspects. Part II. Parameters Determining Release Rate

Abstract

Parameters influencing the release rates from polymeric dosage forms are considered: geometric characteristics of the article, crystallinity, molecular weight and molecular weight distribution of biodegradable polymer, and also cross-linking degree, drug content, and so forth.     

Drug Release Kinetics of Spray-Dried Chitosan Microspheres

The aim of this article was to investigate the drug release kinetics of spray-dried chitosan microspheres using various kinetic models. The mean particle size and encapsulation efficiency of cross-linked chitosan microspheres was between 3.8 and 4.2 μm and 96.3 and 98.7%, respectively. Spray-dried chitosan microspheres were spherical in shape with smooth surface. The surface morphology of spray-dried chitosan microspheres was affected by the crystallinity of the loaded drug and cross-linking agent. The release data of the spray-dried chitosan microspheres were treated with zero-order, first-order, Higuchi, Korsmeyer, and Kopcha kinetic models and best fit was observed with Higuchi model, indicating the release of drug from spray-dried chitosan microspheres followed Fick's law of diffusion.     

Drug Release Kinetics of Spray-Dried Chitosan Microspheres

The aim of this article was to investigate the drug release kinetics of spray-dried chitosan microspheres using various kinetic models. The mean particle size and encapsulation efficiency of cross-linked chitosan microspheres was between 3.8 and 4.2 μm and 96.3 and 98.7%, respectively. Spray-dried chitosan microspheres were spherical in shape with smooth surface. The surface morphology of spray-dried chitosan microspheres was affected by the crystallinity of the loaded drug and cross-linking agent. The release data of the spray-dried chitosan microspheres were treated with zero-order, first-order, Higuchi, Korsmeyer, and Kopcha kinetic models and best fit was observed with Higuchi model, indicating the release of drug from spray-dried chitosan microspheres followed Fick's law of diffusion.     

缓释微球乙型肝炎疫苗的初步研究

目的　研制缓释微球乙型肝炎疫苗。方法　用聚－ＤＬ－乳酸－聚乙二醇共聚物（ＰＥＬＡ）为材料,包裹乙 型肝炎表面抗原（ＨＢｓＡｇ）,制成缓释微球疫苗。微球的粒径均小于５ｕｍ,平均粒径为２．１７ｕｍ,抗原包裹量为１．２５％, 包裹率为６０－８０％。用 ＳＤＳ－ＰＡＧＥ检测抗原,以微球疫苗免疫 ＢＡＬＢ／ｃ。小鼠。结果 ＨＢｓＡｇ的结构包裹前后是一致 的,小鼠经皮下注射单剂微球疫苗后,在第 １４ｗ,小鼠血清 ＩｇＧ滴度可达到铝佐剂疫苗相当的水平,且维持较高的滴 度。结论采用生物可降解的缓释微球作为乙肝疫苗载体系统具有潜在的优势。     

日化香精控制释放技术及其应用

日化香精的控制释放,对于有效地发挥其功能是十分重要的。 控制释放技术有很多方法,例如：微包囊法,环糊精法,薄膜法,凝胶法,乳化法等。 本文就近期有关日化香精控制释放技术及其在芳香织物、芳香合成纤维、芳香涂料、芳香塑料、空气清新剂等方面的应用作一综述。     

包膜控释肥料研究与产业化开发

从控释和缓释肥料提高肥料利用率的基本原理出发，对国际肥料工业协会(IFA)提出的和国际上公认的肥料养分释放、缓释、控释、控释肥、缓释肥和稳定性肥料的概念和定义进行了讨论和认定。介绍了山东农业大学主持承担的国家“948”项目、农业部跨越计划项目和山东省优秀中青年科学家科研奖励基金项目——包膜控释肥研究与开发的进展情况，包括包膜控释肥的包膜材料与工艺流程的选择、研制的包膜控释肥生产设备、开发出的控释肥系列品种、控释肥的质量检测标准、控释肥在多种作物上的应用效果，并分析了控释肥的经济、社会、生态效益及推广应用前景。