纳米分散系的研究进展

通过查阅国内外相关文献,综述了纳米分散系的主要类型、制备方法、在药学领域中的应用以及当前存在的问题。结果表明,作为一种新型给药系统,纳米分散系具有广阔的开发与应用前景。     

纳米制剂在透皮药物递送系统中的应用研究进展

透皮药物递送系统作为一种非侵入式给药途径，与传统给药方式相比具有顺应性高、无首过效应等优势。纳米技术的应用使得透皮药物递送系统的药物选择范围进一步扩大，并提高了药物的治疗效果，形成了一种极具价值、令人期待的新型给药方式。目前常用于透皮药物递送系统的纳米制剂包括纳米乳、脂质纳米囊泡、脂质纳米粒、聚合物纳米粒、纳米晶体、溶致液晶纳米粒等。介绍了皮肤屏障和透皮递送的常用促渗方法，综述了各类应用于透皮药物递送系统的纳米制剂及其与物理促渗方法联合应用的研究进展，以期为纳米制剂在透皮递送方面的深入研究提供参考。     

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。     

新型纳米粒给药系统——纳米结构的脂质载体

固体脂质纳米粒（SLN）已被公认是一种新型的纳米粒给药系统，但SLN有不同程度的潜在问题。作为新一代的纳米粒给药系统——纳米结构的脂质载体（Nanostructured lipid carriers，NLC）可减小或者避免SLN有限载药能力及储藏过程包封药物泄漏的问题，而且能调整SLN的释放曲线。NLC以固体脂质与物态上相异的液体脂质混合制备得到，形成3种类型特殊结构的脂质骨架：结晶不完全态、无定形态、复合态。现介绍一种特殊的制备方法，不仅适合于制备NLC，而且也可作为制备高粒子浓度（30％～95％）SLN分散液的方法。描述了NLC作为给药系统潜在的应用前景。     

纳米混悬液的制备方法及其在药物输送中应用的研究进展

纳米混悬液系采用少量表面活性剂或其它载体等稳定纯药物粒子所形成的一种亚微米胶体分散体系。纳米混悬液可增大难溶性药物的溶解度,提高药物的有效性和安全性等。通过查阅国内外相关文献,文章就纳米混悬液的制备方法、评价方法及在药物输送中的应用进行了综述。纳米混悬液的制备技术主要有两种,即Bottom up技术和Top down技术。其评价方法主要包括:粒径及粒径分布、Zeta电势、药物晶体状态等。纳米混悬液在各种给药途径中均有优势。纳米混悬液做为一种新型的药物载体有着广阔的研究前景     

虾青素纳米制剂研究进展及其策略分析

虾青素作为一种脂溶性的类胡萝卜素，具有强大的抗氧化性能，但因水溶性差，对温度、光、氧等外界环境敏感，生物利用度低等问题而限制了应用。新型纳米给药系统对于改善上述缺陷具有优势。该文就目前基于脂质、多糖和蛋白的虾青素新型纳米递送系统的研究现状和应用进行综述，并归纳与思考了虾青素纳米递送系统的研究方向，期望为虾青素的临床应用提供帮助。     

聚乙二醇1000维生素E琥珀酸酯的药剂学应用进展

聚乙二醇1000维生素E琥珀酸酯(TPGS)作为一种特性生物材料,有着广阔的药剂学应用前景。在药剂辅料中,TPGS可作为增溶剂、吸收促进剂、乳化剂、渗透促进剂。在新型给药系统中,可用于制备固体分散体、胶束、前体药物,亦可作为P-糖蛋白抑制剂,发挥抗多药耐药作用。本文就TPGS在传统药剂学和新型给药系统中的最新应用进行综述,为其进一步应用研究提供参考。     

聚酯型高分子纳米载药系统研究进展

目的介绍PCL、PLGA、PLA等聚酯型高分子纳米载药系统的研究进展。方法查阅相关文献，总结归纳纳米粒的制备、性能特点、在药物输送系统DDS中的应用等。结果聚酯型高分子纳米载药系统制备简单，有靶向、缓释特征，在DDS中应用较广。结论聚酯型高分子纳米载药系统可作为有前途的新型给药系统。     

新型靶向制剂阿昔洛韦药质体的家兔体内的研究

目的 探讨新型靶向制剂阿昔洛韦药质体的家兔体内行为特点和靶向效果。方法 制各得对新型给药系统阿昔洛韦药质体，检测了药质体的粒度分布和表面电位，家兔静脉给药后进行药物动力学和体内分布研究。结果 阿昔洛韦药质体为纳米分散混悬液，粒子携带负电荷，静脉给药后迅速从血液循环中清除，主要分布于肝肺脾。结论 阿昔洛韦药质体具有明显的网状内皮系统靶向作用。     

纳米载体应用于透皮给药系统的研究进展

纳米载体经皮给药系统是近几年经皮给药的研究热点。本文综述了各种纳米载体在经皮给药系统中应用的研究进展,其中囊泡、微乳和固体脂质纳米粒作为经皮给药载体已得到相对深入的研究,而新型纳米载体如胶束、树状大分子和细胞促透多肽等尽管研究较少,但基于其明显的促渗作用,将会为经皮给药系统的研究提供新方向。     

A nano-disperse ferritin-core mimetic that efficiently corrects anemia without luminal iron redox activity

The 2-5 nm Fe(III) oxo-hydroxide core of ferritin is less ordered and readily bioavailable compared to its pure synthetic analogue, ferrihydrite. We report the facile synthesis of tartrate-modified, nano-disperse ferrihydrite of small primary particle size, but with enlarged or strained lattice structure (~ 2.7 Å for the main Bragg peak versus 2.6 Å for synthetic ferrihydrite). Analysis indicated that co-precipitation conditions can be achieved for tartrate inclusion into the developing ferrihydrite particles, retarding both growth and crystallization and favoring stabilization of the cross-linked polymeric structure. In murine models, gastrointestinal uptake was independent of luminal Fe(III) reduction to Fe(II) and, yet, absorption was equivalent to that of ferrous sulphate, efficiently correcting the induced anemia. This process may model dietary Fe(III) absorption and potentially provide a side effect-free form of cheap supplemental iron.From the Clinical EditorSmall size tartrate-modified, nano-disperse ferrihydrite was used for efficient gastrointestinal delivery of soluble Fe(III) without the risk for free radical generation in murine models. This method may provide a potentially side effect-free form iron supplementation.     

蛋白多肽类药物纳米粒口服给药系统的研究进展

目的综述近年来纳米粒作为蛋白质多肽类药物口服传递系统方面的研究现状和进展。方法分析有关文献资料,从纳米粒给药系统的载体材料、口服药效等方面进行了概述。结果纳米粒给药系统可提高蛋白质和多肽类药物的口服吸收效率,提高此类药物的生物利用度。结论纳米粒给药系统在口服传递蛋白质和多肽类药物方面有着广阔的研究和应用前景。     

Intraoral drug delivery

The oral availability of many drugs is poor because of the pH of the stomach, the presence of enzymes, and extensive first-pass metabolism. Traditionally, these drugs have been administered as parenteral drug delivery systems, which invariably leads to poor patient compliance. This has made the pharmaceutical industry look for alternative routes of drug delivery. One possible route is via the oral cavity. This review compares the many different and novel drug delivery systems that have been developed for absorption through the oral cavity as well as those that undergo quick disintegration or dissolution in the oral cavity. Systems for oral delivery include mucoadhesive patches, films and tablets, as well as quick-disintegrating wafers, tablets and films. There are many examples of drugs that have been formulated into intraoral absorptive drug delivery systems as well as quick-disintegrating drug delivery systems. The fact that most of the research being conducted on intraoral drug delivery systems is driven by pharmaceutical manufacturers demonstrates the need for such drug delivery systems. As we begin to discover more about oral mucosal drug delivery, and develop much more sophisticated drug delivery systems, many more drugs will be formulated as intraoral systems. There is no doubt that the need for these systems is real, and many classes of drugs could benefit from this noninvasive type of drug delivery. The challenge now is to synthesize drug moieties that exhibit increased absorption across the oral mucosa and are more potent in their action. Intraoral drug delivery systems are possibly one of the very few drug delivery systems that seem to be ahead of the development of new drug compounds that are effectively absorbed across tissue membranes.     

Gastroretentive dosage forms: a review with special emphasis on floating drug delivery systems

In the present era, gastroretentive dosage forms (GRDF) receive great attention because they can improve the performance of controlled release systems. An optimum GRDF system can be defined as a system which retains in the stomach for a sufficient time interval against all the physiological barriers, releases active moiety in a controlled manner, and finally is easily metabolized in the body. Physiological barriers like gastric motility and gastric retention time (GRT) act as obstacles in developing an efficient GRDF. Gastroretention can be achieved by developing different systems like high density systems, floating drug delivery systems (FDDS), mucoadhesive systems, expandable systems, superporous systems, and magnetic systems. All these systems have their own merits and demerits. This review focused on the various aspects useful in development of GRDF including the current trends and advancements.     

Recombinant expression systems for allergen vaccines

Allergen immunotherapy of future is likely to be based on allergy vaccines that contain engineered allergens modified to abolish or substantially reduce their IgE-binding activity in order to remove the risk of unwanted anaphylactic responses. The development of efficient systems for the production of recombinant allergens in sufficient quantities is requirement for establishing use of engineered allergens as components of allergy vaccines. This review outlines relative advantages and disadvantages of various heterologous systems for production of recombinant allergens. Microbial systems are most convenient and cost effective platforms for the production of recombinant allergens. However, lack of post-translational processing implies that some allergens have to be expressed in eukaryotic systems for proper folding and post-translational modifications such as glycosylation. Yeast systems can yield high levels of recombinant allergens but often are associated with hyper- glycosylation problems. Mammalian cell culture systems offer suitable post -translational modifications but are nearly hundred fold more expensive than microbial systems. The use of plants as bio-factories for production of recombinant allergens is emerging as a very attractive option as plants-based production system offer several advantages over other expression systems such as post translational processing of proteins, low production costs, scale up ability and enhanced safety due to absence of animal or human pathogens.     

An update on ready-to-use intravenous delivery systems

The advent of ready-to-use intravenous (IV) delivery systems, particularly small-volume parenterals less than 250 mL has contributed greatly to pharmacy and patient care. Since their introduction in the late 1970s, the availability and variety of systems have increased. The purpose of this article is to update practitioners on small-volume parenterals systems that have a large product availability requiring little manipulation to make the system patient-specific. Additional benefits such as extended stability, potential for decreasing waste of products, as well improved end-quality are also discussed. With the benefits described that these systems have over the traditional method of preparing small-volume parenterals, there is still hesitation to fully utilize these systems. The primary reason for this seems to be the issue of cost. With various rebate incentive programs offered by manufacturers as well as the benefits that the systems provide, ready-to-use IV delivery systems are comparable in price to the traditional method of preparing small-volume parenteral agents.     

The benefits and challenges associated with the use of drug delivery systems in cancer therapy

The use of drug delivery systems as nanocarriers for chemotherapeutic agents can improve the pharmacological properties of drugs by altering drug pharmacokinetics and biodistribution. Among the many drug delivery systems available, both micelles and liposomes have gained the most attention in recent years due to their clinical success. There are several formulations of these nanocarrier systems in various stages of clinical trials, as well as currently clinically approved liposomal-based drugs. In this review, we discuss these drug carrier systems, as well as current efforts that are being made in order to further improve their delivery efficacy through the incorporation of targeting ligands. In addition, this review discusses aspects of drug resistance attributed to the remodeling of the extracellular matrix that occurs during tumor development and progression, as well as to the acidic, hypoxic, and glucose-deprived tumor microenvironment. Finally, we address future prospective approaches to overcoming drug resistance by further modifications made to these drug delivery systems, as well as the possibility of coencapsulation/coadministration of various drugs aimed to surmount some of these microenvironmental-influenced obstacles for efficacious drug delivery in chemotherapy.     

Effectiveness of and challenges faced by surveillance systems

Drug information or surveillance systems have been developed in an attempt to measure illicit drug use and predict new trends. In Australia, three systems are specifically designed to monitor drug use trends and related harm. These systems have their own strengths and weaknesses. This perspective offers a discussion of these facets. A series of case studies is used to highlight how surveillance systems can be effective in detecting and monitoring trends of use while highlighting the challenges these systems face. As indicated by the case study of ecstasy, such surveillance systems are effective and can provide unique information when a drug is detected and becomes 'established' in the market but the methodology of these systems is challenged when new drug classes emerge rapidly, as is illustrated by emerging psychotropic substances such as mephedrone.