纳米胶束作为药物载体的研究进展

药剂学中以表面活性剂或高分子载体材料形成的胶束为载体制成的药物胶柬制剂正受到越来越多的关注,而粒径为纳米尺寸的纳米胶束作为药物的载体具有许多独特的优势,如缓控释及靶向特性、与细胞和组织的生物相容性等优点,在新型载药系统领域显示了良好的应用前景。本文简要综述了纳米胶束的性质、形成机理、载体材料、制备方法、体内外释药特性及在药物载体方面的应用研究。     

壳聚糖及其衍生物在药物载体中的应用

摘 要壳聚糖及其衍生物具有无毒、良好的生物相容性和可降解性、黏膜黏附性和促渗性等优点,在药物载体领域具有较为广阔的研究及应用前景。本文结合国内外最新发表的相关文献,对壳聚糖及其衍生物作为相关药物载体的应用以及作用机制进行分析讨论,并对其作为抗肿瘤药物靶向载体、缓控释药物载体、眼用药物载体、基因载体和凝胶基质的应用及研究进展进行综述。     

自乳化药物传递系统的研究概况

目的:总结自乳化药物传递系统的研究概况.方法:对近期自乳化药物传递系统的形成机制、处方组成、体外质量评价及其在药剂学方面的应用进行介绍.结果与结论:自乳化药物传递系统对亲脂性和水难溶性的药物是一个非常有前景的新型载体系统.     

壳聚糖介导的靶向药物传递系统

目的:综述了以壳聚糖或其衍生物为基础的多种特殊靶向载体系统的研究现状。方法:以国内外近年有代表性的文献为依据,进行分析、整理和归纳。结果与结论:由于壳聚糖具有一些独特的物理和生物特性,并且通过修饰后增加了壳聚糖的一些性质,使其成为优良的药物载体,从而实现药物的靶向性。这一载体材料近年来逐渐受到重视,具有良好的开发和应用前景。     

壳聚糖在新型给药系统中的应用

综述壳聚糖的物理化学和生物特性及在基因转染和不同给药系统中的应用研究近况。壳聚糖作为新型药用辅料,已受到越来越多的关注,对其应用的开发和研究已渗透到药剂学的多个领域。壳聚糖用作非病毒基因载体,也已成为近年来的研究热点之一。它也被广泛研究应用于眼部、鼻腔、口腔、胃内、小肠和结肠等靶向给药载体。     

药剂学中的分子动力学模拟

介绍了研究药剂学的新方法--分子动力学的基本原理及常用软件,及近来用其研究环糊精包合物、阳离子脂质体、含脂肪酸甘油酯的体系和聚合物载体等的案例.这些研究在分子水平上揭示载体的性质及药物与载体相互作用的本质,为改进药物传递系统提供了理论指导.分子动力学模拟将成为药剂学研究的重要补充手段.     

壳聚糖在药物剂型中的应用

壳聚糖具有良好的生物可降解性、生物相容性、成膜性、无毒性与可塑性,已经成为当前药物剂型中应用最为广泛的高分子材料。有文献报道,壳聚糖制成的缓释制剂有助于提升药物有效性、安全性与可靠性,它可以提升药物缓释速度,降低给药频率。现阶段,壳聚糖及其衍生物作为靶向制剂载体,以其显著优势被广泛应用于靶向给药系统研究中,但是其应用多结合戊二醛作为化学交联剂,具有一定毒副作用及其它不足。因此,关于壳聚糖改性研究不断开展,为其载药能力的提升具有一定的指导作用。     

壳聚糖衍生物及其胶束：特性、功能化修饰和在药物传递系统中的应用

壳聚糖是一种天然多糖,具有无毒、可生物降解、生物相容性等诸多优点,但水溶性差的自身特点限制了其在药剂学中的应用,而其经合理的结构设计、修饰和优化,可获得性能良好的两亲性壳聚糖衍生物,这些衍生物在水溶液中能自组装成具有良好药物传输性能（如载药量、稳定性、刺激敏感性、靶向性等）的胶束,并被广泛应用于构建药物传递系统,以改善药物的溶解性、靶向性、生物利用度及耐药性．降低药物的毒副作用。综述壳聚糖衍生物结构对其胶束药物传输性能的影响以及壳聚糖衍生物及其胶束的功能化修饰和在药物传递系统中的应用。     

药物控释制剂载体的研究进展

目的药物控释制剂载体是随着药物学、生物材料科学和临床医学的发展而新兴的给药技术。药物控制释放体系在机体内显示出被动靶向、缓释的优点。药物缓释载体材料起着关键作用。笔者重点对几类药物控释载体材料的应用及发展进行综述。方法查阅国内外相关文献并进行分析、归纳。结果了解适合不同药物的药物载体材料,有助于达到理想的药物控制释放效果。结论药物控释制剂具有很广阔的应用前景,目前药物载体的研究还主要是基于材料学的角度,应当加强其药剂学、药动学方面的研究。     

壳聚糖微粒及纳米制剂在药剂学中的研究进展

［摘要］查阅国内外相关文献,总结壳聚糖微粒及纳米制剂的主要制备方法及药物的释放方式,阐述壳聚糖微粒纳米制剂在药剂学的主要应用。壳聚糖微粒纳米制剂比表面结构大,生物相容性好,具有优良的药物包埋性能和控制药物释放的能力,是极有发展前景的新型制剂给药系统。     

Impact of chitosan composites and chitosan nanoparticle composites on various drug delivery systems: A review

Chitosan is a promising biopolymer for drug delivery systems. Because of its beneficial properties, chitosan is widely used in biomedical and pharmaceutical fields. In this review, we summarize the physicochemical and drug delivery properties of chitosan, selected studies on utilization of chitosan and chitosan-based nanoparticle composites in various drug delivery systems, and selected studies on the application of chitosan films in both drug delivery and wound healing. Chitosan is considered the most important polysaccharide for various drug delivery purposes because of its cationic character and primary amino groups, which are responsible for its many properties such as mucoadhesion, controlled drug release, transfection, in situ gelation, and efflux pump inhibitory properties and permeation enhancement. This review can enhance our understanding of drug delivery systems particularly in cases where chitosan drug-loaded nanoparticles are applied.     

Chitosan salts coated with stearic acid as colon-specific delivery systems for vancomycin

Site-specific controlled release systems have been extensively investigated during the last decade. The aim of this study was to describe a pH-dependent drug release system based on chitosan salts for vancomycin hydrochloride delivery. Chitosan salts with succinic acid, adipic acid, and suberic acid were prepared by spray-drying and were coated with stearic acid by the same technique. This study characterized the carriers in terms of morphology, size, swelling, mucoadhesive properties, and drug loading and focused on the in vitro, influence of chitosan salts on the release behavior of vancomycin hydrochloride from the uncoated and coated systems at pH levels of 2.0, 5.5, and 7.6.     

Chitosan microspheres in novel drug delivery systems

The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems.     

Targeted delivery of low molecular drugs using chitosan and its derivatives

Chitosan has prompted the continuous impetus for the development of safe and effective drug delivery systems because of its unique physicochemical and biological characteristics. The primary hydroxyl and amine groups located on the backbone of chitosan allow for chemical modification to control its physical properties. When the hydrophobic moiety is conjugated to a chitosan molecule, the resulting amphiphile may form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site of action. Chemical attachment of the drug to the chitosan throughout the functional linker may produce useful prodrugs, exhibiting the appropriate biological activity at the target site. Mucoadhesive and absorption enhancement properties of chitosan increase the in vivo residence time of the dosage form in the gastrointestinal tract and improve the bioavailability of various drugs. The main objective of this review is to provide an insight into various target-specific carriers, based on chitosan and its derivatives, towards low molecular weight drug delivery. The first part of the review is concerned with the organ-specific delivery of low molecular drugs using chitosan and its derivatives. The subsequent section considers the recent developments of drug delivery carriers for cancer therapy with special focus on various targeting strategies.     

壳聚糖及其衍生物在药物递送中的研究进展

壳聚糖是自然界中存在的唯一的带正电的碱性氨基多糖,具有来源丰富、无毒、低免疫原性、良好的生物可降解性和生物相容性等优点。壳聚糖的活性氨基和羟基,经各种化学修饰如羧基化、巯基化、季铵化、疏水修饰、长循环修饰和靶向修饰,可获得具有特殊功能特性的衍生物,广泛用作药物和基因的载体材料。是近年来药剂学领域的研究热点。本文就近年来壳聚糖及其衍生物在药物递送中的研究进展作一综述。     

Synthesis and characterization of membranes obtained by graft copolymerization of 2-hydroxyethyl methacrylate and acrylic acid onto chitosan

Chitosan based membranes to be applied on wound healing as topical drug delivery systems were developed by graft copolymerization of acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto chitosan using cerium ammonium nitrate as chemical initiator. Evidence for graft copolymerization of the vinyl monomers onto chitosan was obtained by FTIR and DMTA. Swelling degree, cytotoxicity, thrombogenicity and haemolytic activity of these membranes were evaluated. Chitosan-graft-AA-graft-HEMA showed to be the best matrix for drug delivery systems than chitosan-graft-AA because it retains good swelling properties, but the content in HEMA has improved cytocompatibility, hemocompatibility and thrombogenic character.     

Modified chitosan hydrogels as drug delivery and tissue engineering systems: present status and applications

Chitosan, a natural cationic polysaccharide, is prepared industrially by the hydrolysis of the aminoacetyl groups of chitin, a naturally available marine polymer. Chitosan is a non-toxic, biocompatible and biodegradable polymer and has attracted considerable interest in a wide range of biomedical and pharmaceutical applications including drug delivery, cosmetics, and tissue engineering. The primary hydroxyl and amine groups located on the backbone of chitosan are responsible for the reactivity of the polymer and also act as sites for chemical modification. However, chitosan has certain limitations for use in controlled drug delivery and tissue engineering. These limitations can be overcome by chemical modification. Thus, modified chitosan hydrogels have gained importance in current research on drug delivery and tissue engineering systems. This paper reviews the general properties of chitosan, various methods of modification, and applications of modified chitosan hydrogels.     

Chitosan: some pharmaceutical and biological aspects--an update

Chitosan, a natural polysaccharide, is being widely used as a pharmaceutical excipient. It is obtained by the partial deacetylation of chitin, the second most abundant natural polymer. Chitosan comprises a series of polymers varying in their degree of deacetylation, molecular weight, viscosity, pKa etc. The presence of a number of amino groups permit chitosan to chemically react with anionic systems, thereby resulting in alteration of physicochemical characteristics of such combinations. Chitosan has found wide applicability in conventional pharmaceutical devices as a potential formulation excipient, some of which include binding, disintegrating and tablet coating properties. The polymer has also been investigated as a potential adjuvant for swellable controlled drug delivery systems. Use of chitosan in novel drug delivery as mucoadhesive, gene and peptide drug administration via the oral route as well as its absorption enhancing effects have been explored by a number of researchers. Chitosan exhibits myriad biological actions, namely hypocholesterolemic, antimicrobial and wound healing properties. Low toxicity coupled with wide applicability makes it a promising candidate not only for the purpose of drug delivery for a host of drug moieties (antiinflammatories, peptides etc.) but also as a biologically active agent. It is the endeavour of the present review to provide an insight into the biological and pharmaceutical profile of chitosan. Various investigations carried out recently are reported, although references to research performed on chitosan prior to the recent reviews have also been included, where appropriate.