壳聚糖在缓释制剂中的应用

壳聚糖是一种天然聚氨基葡萄糖，具有优良的生物降解性能和生物亲和性。介绍壳聚糖的性能特点及其在缓释药物剂型研究中的应用。     

壳聚糖在制剂中的应用研究

综述了壳聚糖在肽类口服给药系统,微球,结肠靶向给药,涂膜剂,滴眼剂等制剂的国内外应用研究现状。     

壳聚糖及其衍生物在药物缓控释制剂中的应用进展

壳聚糖(chitosan)是自然界存在的第二大类多糖-甲壳素(chitin)的衍生物,是一类由2-氨基-2-脱氧葡萄糖通过β- 1,4-糖苷键连接而成的带正电荷的直链多糖,可通过碱水解法脱去甲壳素的乙酰基而制得。壳聚糖是天然多糖中唯一的碱性多糖,分子链上有羟基和胺基两种活泼的反应基团,可通过酯化、酰化、醚化、羧基化、醛化、水解等各种反应,引     

靶向制剂进展

本文较为全面地叙述近年来国内外有关全身作用靶向制剂，包括毫微囊，脂质体等的作用原理，类型，特点，研究现状及存在问题。并展望了各种靶制的研究与开发前景。     

壳聚糖及其衍生物在口服制剂中的应用

壳聚糖及其衍生物具有优良的生物特性及物理化学性质，在药物制剂中有广阔的应用前景。在调研国内外相关资料的基础上。结合实际工作对目前正在研究并取得一定进展的壳聚糖及其衍生物在口服药物制剂中的应用作简要综述。     

壳聚糖在医院制剂的应用

甲壳素是自然界生物(水产甲壳类的蟹、虾、昆虫的外壳等)所含有的一种氨基多糖,它能生物合成,又可生物分解,且不污染环境的天然高分子,其构造与纤维素类似,见图1。     

纳米制剂技术在骨靶向给药系统中的应用进展

骨骼是人体的重要组成部分,由骨膜、骨质和骨髓构成.正常骨骼时刻处于骨形成和骨吸收的骨重建动态平衡中,两者相互协调作用,共同维持骨骼的生理功能.如果正常骨重建过程发生病变,就会产生各种骨疾病,如骨质疏松症、畸形性骨炎、骨转移瘤、原发性和继发性骨肿瘤、骨关节炎等.由于骨组织硬度大、渗透性差和生理生化过程特殊,一般给药途径很难使药物转运至病灶部位.药物常须通过全身给药,增加剂量才能在骨组织中达到有效的治疗浓度,这样不仅降低了药物的治疗指数,而且也会对患者的非骨组织或器宫造成较为严重的不良反应.骨靶向给药系统(osteotropic drug delivery system,ODDS)能特异性地将药物转运至骨组织从而减小其在非骨组织的分布与结合[1].     

中药靶向制剂的研究进展

对近年来靶向制剂研究文献进行检索,从脂质体,微球和微囊,纳米粒,乳剂,前体前药,单克隆抗体等方面介绍中药靶向制剂的研究进展,并介绍了中药靶向制剂研究中存在的问题。     

叶酸受体靶向制剂作用机制及临床应用进展

对癌症治疗,传统的药物传递系统已经显示是低效的,化疗因剧烈的副作用使其使用常常受到限制.抗肿瘤药物特定传递已经逐渐成为一个吸引人的癌症治疗方法[1].叶酸受体靶向制剂作为一个有前途的癌症治疗方法逐渐引起人们的关注,归因于叶酸的小分子体积和结合到细胞表面的叶酸受体的高亲和力[2].     

靶向制剂的研究进展

综述了近10多年来发表的有关靶向制剂研究论文与专著,叙述了靶向制剂应具备的三个要素,评价靶向性的三个参数。介绍了采用载体微粒粒径控制的被动靶向,达到特定靶部位释药的主动靶向,物理化学法靶向以及用空白载体微粒先削弱巨噬细胞作用的牵制靶向等方法,并提出了靶向制剂的发展趋势与前景。     

壳聚糖微/纳米粒在定向给药系统中的应用研究

目的：介绍壳聚糖微/纳米粒在新型定向给药系统中的应用,为发展安全高效的壳聚糖微/纳米粒定向给药系统提供参考。方法：综合近年来出版的有关文献,对壳聚糖基本性质,定位给药于各组织部位进行了探讨。结果：壳聚糖微/纳米粒可应用于脑、眼、鼻、口、肺、胃、小肠、结肠等器官靶向给药。结论：壳聚糖微/纳米粒作为一种新型药用辅料,在定位给药系统中已经得到了开发和应用。     

壳聚糖纳米粒作为药物递送系统在癌症治疗中的应用

癌症是威胁人类生存的恶性疾病之一。近年来,利用纳米技术将药物靶向递送到肿瘤部位,可以增加疗效并降低毒性,为癌症治疗带来了新希望。壳聚糖是自然界唯一存在的碱性多糖,具有良好的生物相容性和生物可降解性。此外,其反应位点多,可制成不同性质的衍生物,广泛用于药物递送系统和组织工程支架,在生物医药领域具有重要的应用价值。本综述对近年来壳聚糖纳米粒在抗癌药物递送方面的研究进展进行介绍,重点介绍了壳聚糖纳米粒的制备、被动靶向、主动靶向和刺激-响应药物递送系统方面的研究进展。     

肝靶向给药系统的研究进展

通过对近年来国内外报道的肝靶向研究相关文献进行检索,根据肝靶向药物的不同作用机制对肝靶向给药系统的研究进展进行分析和总结。有关肝靶向药物的研究结果表明,肝靶向给药系统能选择性地将药物输送至肝脏病变部位,通过提高其在肝脏病变组织的药物浓度,从而达到增强药物疗效、减少其毒副作用的目的。因此,肝靶向给药系统在肝脏疾病治疗方面具有广阔的应用前景。     

核苷酸适体在靶向给药系统中的应用进展

适体,即体外合成筛选得到的能特异性地与靶分子结合的一段寡核苷酸序列。由于其独特的性质,在靶向给药系统中有着广阔的应用前景,目前已成为靶向给药研究领域的热点。综述了适体在靶向给药系统中的优势及其应用进展,并对其应用前景和面临的问题进行分析。     

细胞膜仿生纳米技术在肿瘤靶向递药系统中的研究进展

纳米技术的发展为构建安全高效、精准可控的药物递送系统(drug delivery system, DDS)提供了可能。其中,有机或无机合成纳米载体已被广泛报道并用于肿瘤治疗药物的递送,但部分载体存在易被机体内免疫系统清除、制备过程繁琐和体内安全性较差等问题。近年来,随着生物医学的发展,基于仿生技术的生物膜介导的纳米药物递送系统,因其有机整合了天然生物膜的低免疫原性、肿瘤靶向性和智能纳米载体设计的可调控性、多功能性,有望实现纳米技术在肿瘤靶向治疗上的新突破。本文基于细胞膜仿生技术和纳米医学在肿瘤治疗领域的最新进展,从细胞膜仿生纳米技术的实验基础、膜仿生纳米递药平台的分类和在肿瘤靶向治疗上的应用三方面进行阐述,旨在为仿生智能DDS的设计及其在肿瘤靶向治疗中的发展提供参考。     

Mechanisms of drug release in pH-sensitive micelles for tumour targeted drug delivery system: A review

During the past decades, chemotherapy has been regarded as the most effective method for tumor therapy, but still faces significant challenges, such as poor tumor selectivity and multidrug resistance. The development of targeted drug delivery systems brings certain dramatic advantages for reducing the side effects and improving the therapeutic efficacy. Coupling a specific stimuli-triggered drug release mechanism with these delivery systems is one of the most prevalent approaches for targeted therapy. Among these approaches, pH-sensitive micelles are regarded as the most general strategy with advantages of increasing solubility of water-insoluble drugs, pH-sensitive release, high drug loading, etc.This review will focus on the potential of pH-sensitive micelles in tumor therapy, analyze four types of drug-loaded micelles and mechanisms of drug release and give an exhaustive collection of recent investigations. Sufficient understanding of these mechanisms will help us to design more efficient pH-sensitive drug delivery system to address the challenges encountered in targeted drug delivery systems for tumor therapy.     

中药结肠靶向给药系统研究进展

目的对结肠靶向给药(CTDD)系统的相关进展全面综述,探讨其今后的发展方向,为研究人员提供参考与依据。方法查阅国内外19种期刊25篇相关文献,并进行分析、归纳。结果中药CTDD系统包括pH依赖型、时间依赖型、微生物酶解型、生物黏附型、压力依赖型、脉冲型和联合应用型。结论中药CTDD具有广阔的应用前景,但中药指标成分、体内评价等方面的研究还需加强。     

Hydrophobically modified carboxymethyl chitosan nanoparticles targeted delivery of paclitaxel

Specific targeting of tumor cells to achieve higher drug levels in tumor tissue and to overcome the side effects is the major goal in cancer therapy. Nanoparticles encapsulating a hydrophobic core in their nanoreservoir structure were developed as a carrier for a water-insoluble drug, paclitaxel. In the present study, target-oriented nanoparticles based on biodegradable O-carboxymethyl chitosan modified with stearic acid. The surface of the nanoparticles was modified by covalent attachment of folic acid (FA) by simple carbodimide reaction to achieve tumor cell targeting property. Nanoparticles were prepared by the sonication method without involving any surfactants/emulsifiers. The nanoparticles were characterized by various state-of-the-art techniques, including laser light scattering for particles size distribution, field emission scanning electron microscopy and transmission electron microscope for surface morphology. The drug release property and the cytotoxicity of the drug loaded nanoparticles to both cancerous and noncancerous cells were evaluated in cell culture system. To our knowledge, this is the first study demonstrating a FA modified hydrophobically chitosan with paclitaxel-loaded nanoparticles targeting of folate receptor overexpressing cancer cells.     

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.     

Formulation and evaluation of chitosan microspheres of aceclofenac for colon‐targeted drug delivery

The objective of this investigation was to develop novel colon specific drug delivery. Aceclofenac, a NSAID, was successfully encapsulated into chitosan microspheres. Various formulations were prepared by varying the ratio of chitosan, span‐85 and stirring speed and the amount of glutaraldehyde. The SEM study showed that microspheres have smooth surfaces. Microspheres were characterised by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) to confirm the absence of chemical interactions between drug and polymer and to know the formation of microspheres structure. The microspheres were evaluated for particle size, encapsulation efficiency, drug loading capacity, mucoadhesion studies, stability studies, in vitro and in vivo drug release studies. Particle sizes, as measured by the laser light scattering technique, were of an average size in the range 41–80 µm. The swelling index was in the range 0.37–0.82 and the entrapment efficiency range was 51–75% for all the formulations. The optimised batch ACM₁₃ released 83.6% at 8 h and 104% at 24 h in SCF containing rat caecal content. Eudragit coated chitosan microspheres prevented the release of the aceclofenac in the physiological environment of the stomach and small intestine and released 95.9±0.34% in the colon. With regard to release kinetics, the data were best fitted with the Higuchi model and showed zero order release with non‐Fickian diffusion mechanism. The in vivo findings suggest that aceclofenac microspheres exhibit a prolonged effect of aceclofenac in rats and produce a significant anti‐inflammatory effect. The findings of the present study conclusively state that chitosan microspheres are promising for colon targeting of aceclofenac to synchronise with chronobiological symptoms of rheumatoid arthritis. Copyright © 2010 John Wiley & Sons, Ltd.