Recent progress in drug delivery systems for anticancer agents

Recent progress in understanding the molecular basis of cancer brought out new materials such as oligonucleotides, genes, peptides and proteins as a source of new anticancer agents. Due to their macromolecular properties, however, new strategies of delivery for them are required to achieve their full therapeutic efficacy in clinical setting. Development of improved dosage forms of currently marketed anticancer drugs can also enhance their therapeutic values. Currently developed delivery systems for anticancer agents include colloidal systems (liposomes, emulsions, nanoparticles and micelles), polymer implants and polymer conjugates. These delivery systems have been able to provide enhanced therapeutic activity and reduced toxicity of anticancer agents mainly by altering their pharmacokinetics and biodistribution. Furthermore, the identification of cell-specific receptor/antigens on cancer cells have brought the development of ligand- or antibody-bearing delivery systems which can be targeted to cancer cells by specific binding to receptors or antigens. They have exhibited specific and selective delivery of anticancer agents to cancer. As a consequence of extensive research, clinical development of anticancer agents utilizing various delivery systems is undergoing worldwide. New technologies and multidisciplinary expertise to develop advanced drug delivery systems, applicable to a wide range of anticancer agents, may eventually lead to an effective cancer therapy in the future.     

Polysaccharides-based nanoparticles as drug delivery systems

Natural polysaccharides, due to their outstanding merits, have received more and more attention in the field of drug delivery systems. In particular, polysaccharides seem to be the most promising materials in the preparation of nanometeric carriers. This review relates to the newest developments in the preparation of polysaccharides-based nanoparticles. In this review, four mechanisms are introduced to prepare polysaccharides-based nanoparticles, that is, covalent crosslinking, ionic crosslinking, polyelectrolyte complex, and the self-assembly of hydrophobically modified polysaccharides.     

渗透泵药物传递系统制备技术研究进展

渗透泵药物传递系统由于能够平稳的释放药物,且释药不易受药物的理化性质、病人生理因素及摄入食物的影响,日益受到药学工作者的关注.目前,已经上市销售的渗透泵片数目对比10年前增长了近1倍.该文简述了渗透泵药物传递系统的结构分类、详细介绍了口服渗透泵制备技术近年来的研究进展.     

我国药物释放系统发展对策与建议

在综合分析药物释放系统发展趋势、我国药物释放系统发展的实际水平及存在问题的基础上,提出我国药物释放系统发展的对策与建议。     

Benchtop-NMR and MRI--a new analytical tool in drug delivery research

During the last years, NMR spectroscopy and NMR imaging (magnetic resonance imaging, MRI) have been increasingly used to monitor drug delivery systems in vitro and in vivo. However, high installation and running costs of the commonly used superconducting magnet technology limits the application range and prevents the further spread of this non-invasive technology. Benchtop-NMR (BT-NMR) relaxometry uses permanent magnets and is much less cost intensive. BT-NMR relaxometry is commonly used in the food and chemical industry, but so far scarcely used in the pharmaceutical field. The paper shows on several examples that the application field of BT-NMR relaxometry can be extended into the field of drug delivery, including the characterisation of emulsions and lipid ingredients (e.g. the amount and physicochemical state of the lipid) and the monitoring of adsorption characteristics (e.g. oil binding of porous ingredients). The most exciting possibilities of BT-NMR technology are linked with the new development of BT-instruments with imaging capability. BT-MRI examples on the monitoring of hydration and swelling of HPMC-based monolayer and double-layer tablets are shown. BT-MRI opens new MRI opportunities for the non-invasive monitoring of drug delivery processes.     

国内外药物释放系统研究的文献计量学分析

利用互联网Medline数据库、清华全文数据库、欧洲专利数据库和中国知识产权局专利数据库,应用统计和情报分析的方法,对国内外近年来发表的有关药物释放系统(DDS)主题文献的论文进行文献数量、年代及研究内容的统计分析,同时对国内外药物制剂专利公布情况进行资料统计,对比分析国内外DDS的研究领域、研究重点变化及发展趋势,探讨我国未来DDS的研究重点与发展前景。     

Nanostructured lipid carriers (NLCs) as drug delivery platform: Advances in formulation and delivery strategies

NLCs have provoked the incessant impulsion for the development of safe and valuable drug delivery systems owing to their exceptional physicochemical and then biocompatible characteristics. Throughout the earlier period, a lot of studies recounting NLCs based formulations have been noticeably increased. They are binary system which contains both solid and liquid lipids aiming to produce less ordered lipidic core. Their constituents particularly influence the physicochemical properties and effectiveness of the final product. NLCs can be fabricated by different techniques which are classified according to consumed energy. More utilization NLCs is essential due to overcome barriers surrounded by the technological procedure of lipid-based nanocarriers’ formulation and increased information of the core mechanisms of their transport via various routes of administration. They can be used in different applications and by different routes such as oral, cutaneous, ocular and pulmonary. This review article seeks to present an overview on the existing situation of the art of NLCs for future clinics through exposition of their applications which shall foster their lucid use. The reported records evidently demonstrate the promise of NLCs for innovate therapeutic applications in the future.     

Self-emulsifying drug delivery systems in oral (poly)peptide drug delivery

Introduction: Oral administration of most therapeutic peptides and proteins is mainly restricted due to the enzymatic and absorption membrane barrier of the GI tract. In order to overcome these barriers, various technologies have been explored. Among them, self-emulsifying drug delivery systems (SEDDS) received considerable attention as potential carriers to facilitate oral peptide and protein delivery in recent years.

Areas covered: This review article intends to summarize physiological barriers which limit the bioavailability of orally administrated peptide and protein drugs. Furthermore, the potential of SEDDS to protect incorporated peptides and proteins towards peptidases and proteases and to penetrate the mucus layer is reviewed. Their permeation-enhancing properties and their ability to release the drug in a controlled way are described. Moreover, this review covers the results of in vivo studies providing evidence for this promising approach.

Expert opinion: As SEDDS can: i) provide a protective effect towards a presystemic metabolism; ii) efficiently permeate the intestinal mucus gel layer in order to reach the absorption membrane; and iii) be produced in a very simple and cost-effective manner, they are a promising tool for oral peptide and protein drug delivery.     

新型给药系统和新技术在光动力疗法中的应用

目的 阐述新型给药系统和制剂新技术在改善光动力疗法（photodynamic therapy,PDT）中的应用研究进展。方法 根据文献,对脂质体、纳米粒、聚合物胶束、微粒表面修饰、微针阵列技术、电学技术、自发光技术、上转换技术等新型给药系统和制剂新技术在PDT中的研究新进展进行阐述。结果 新型给药系统和制剂新技术在较好改善多数光敏剂生理条件下呈疏水性、易聚集及对病变组织选择性不高方面具有独特优势,值得进一步研究。结论 新型给药系统和制剂新技术的开发,有希望将光敏剂传递到人体较深部位并浓集于靶组织,具有广阔的应用前景。     

水飞蓟素自微乳的研制

目的筛选水飞蓟素自微乳的处方并对其体外溶出及稳定性进行考察。方法通过溶解度实验、正交设计及伪三元相图的建立,筛选水飞蓟素自微乳的组成。采用HPLC法测定处方中的药物含量,并对照市售制剂考察其溶出度及稳定性。结果水飞蓟素自微乳化系统的组成为水飞蓟素、油酸乙酯、聚氧乙烯氢化蓖麻油(Cremophor EL)和乙二醇单乙基醚(transcutol)的质量比为0.07∶0.45∶0.45∶0.1;自微乳的平均粒径为72.1 nm;于4种溶出介质中均完全溶出,且溶出曲线明显高于市售制剂;强光照射(4 500 lx)、高温(60℃)及高低温循环实验(40℃和4℃)结果表明,该自微乳性状、含量均无明显变化。结论水飞蓟素自微乳粒径小,溶出度及稳定性良好。     

Nanoparticle drug delivery systems: an excellent carrier for tumor peptide vaccines

In the past 40 years, the nanoparticle drug delivery system for tumor peptide vaccines has been widely studied which also reached a splendid result. Nanomaterial can enhance the targeting of vaccines, help vaccines enter the cells and trigger immune response by themselves. They also help in increasing cellular uptake, improving permeability and efficacy. Currently, several categories of nanopreparation, such as liposome, polymeric micelle, polymeric nanoparticle, gold nanoparticle and so on, are proved that they are appropriate for peptide vaccines. This review we discussed the possible mechanisms of nanomaterial’s action on the regulation of immunological functions and several major applications of this advanced drug delivery system for tumor peptide vaccine.     

Polymeric nanofibers: targeted gastro-retentive drug delivery systems

Background: Conventional oral dosage forms exhibit poor/low bioavailability due to incomplete release of drug and short residence time at the absorption site. Gastro-retentive drug delivery system (GRDDS) is particularly used to improve bioavailability of the drugs, which have narrow absorption window down in the levels of gastrointestinal tract and also to treat local disorders.

Purpose: The purpose of this review is to describe the utility of the nanofibers as gastro-retentive dosage form. From last few decades, formulation scientists have put extensive efforts to develop suitable gastro-retentive drug delivery system, which is appropriate for commercialization. Current approaches used for preparation of gastro-retentive drug delivery system offers limited functional features to control the floating behavior. Recently, an extensive research has been developed to improve the gastric residence time by using nanofibers, which ultimately leads to the increased bioavailability of the drug. Multiple functional features and unique properties of nanofibers improve its gastro retention.

Conclusion: Nanofiber system provides stomach-specific drug release for longer duration; moreover, increased local action of the drug due to prolonged contact time with the gastric mucosa. Thus, the nanofiber system promises to be the potential approach for gastric retention drug delivery system.     

Polymeric nanocarriers as stimuli-responsive systems for targeted tumor (cancer) therapy: Recent advances in drug delivery

In the last decade, considerable attention has been devoted to the use of biodegradable polymeric materials as potential drug delivery carriers. However, bioavailability and drug release at the disease site remain uncontrollable even with the use of polymeric nanocarriers. To address this issue, successful methodologies have been developed to synthesize polymeric nanocarriers incorporated with regions exhibiting a response to stimuli such as redox potential, temperature, pH, and light. The resultant stimuli-responsive polymeric nanocarriers have shown tremendous promise in drug delivery applications, owing to their ability to enhance the bioavailability of drugs at the disease site. In such systems, drug release is controlled in response to specific stimuli, either exogenous or endogenous. This review reports recent advances in the design of stimuli-responsive nanocarriers for drug delivery in cancer therapy. In particular, the synthetic methodologies investigated to date to introduce different types of stimuli-responsive elements within the biomaterials are described. The sufficient understanding of these stimuli-responsive nanocarriers will allow the development of a better drug delivery system that will allow us to solve the challenges encountered in targeted cancer therapy.     

SMART drug delivery systems: Back to the future vs. clinical reality

Recent advances in nanotechnology and material science have re-ignited interest in drug delivery research. Arguably, however, hardly any of the systems developed and strategies proposed are really relevant for shaping the future (clinical) face of the nanomedicine field. Consequently, as outlined in this commentary, instead of making ever more carrier materials, and making nanomedicine both science-fiction and fiction-science, we should try to come up with rational and realistic concepts to make nanomedicines work, in particular in patients.     

口腔黏膜给药系统研究进展

口腔黏膜给药使药物通过颈内静脉直接进入全身循环,避免胃肠道中的酸水解及肝脏首过效应,具有生物利用度高、患者依从性良好的优点。口腔黏膜给药的主要特点是利用生物粘附现象,即生物膜表面与天然或合成聚合物之间的界面分子粘合力现象,延长制剂在生物黏膜表面上的停留时间,以获得更高、更稳定的药物吸收。对口腔黏膜的结构特征、黏膜生物粘附机制、影响黏膜粘附的因素、口腔黏膜剂型设计以及口腔黏膜给药系统的研究进展进行了介绍。

     

A review on phospholipids and their main applications in drug delivery systems

Phospholipids have the characteristics of excellent biocompatibility and a especial amphiphilicity. These unique properties make phospholipids most appropriate to be employed as important pharmaceutical excipients and they have a very wide range of applications in drug delivery systems. The aim of this review is to summarize phospholipids and some of their related applications in drug delivery systems, and highlight the relationship between the properties and applications, and the effect of the species of phospholipids on the efficiency of drug delivery. We refer to some relevant literatures, starting from the structures, main sources and properties of phospholipids to introduce their applications in drug delivery systems. The present article focuses on introducing five types of carriers based on phospholipids, including liposomes, intravenous lipid emulsions, micelles, drug-phospholipids complexes and cochleates.     

Cyclodextrin-based supramolecular systems for drug delivery: Recent progress and future perspective

The excellent biocompatibility and unique inclusion capability as well as powerful functionalization capacity of cyclodextrins and their derivatives make them especially attractive for engineering novel functional materials for biomedical applications. There has been increasing interest recently to fabricate supramolecular systems for drug and gene delivery based on cyclodextrin materials. This review focuses on state of the art and recent advances in the construction of cyclodextrin-based assemblies and their applications for controlled drug delivery. First, we introduce cyclodextrin materials utilized for self-assembly. The fabrication technologies of supramolecular systems including nanoplatforms and hydrogels as well as their applications in nanomedicine and pharmaceutical sciences are then highlighted. At the end, the future directions of this field are discussed.     

口服结肠靶向给药系统的研究概况

口服结肠靶向给药系统具有很多优点,尤其对肠病的治疗。本文综述了口服结肠靶向蛤药系统的机制、类型的研究概况。     

Intra-articular drug delivery systems for osteoarthritis therapy: shifting from sustained release to enhancing penetration into cartilage

Osteoarthritis (OA) is a progressive chronic inflammation that leads to cartilage degeneration. OA Patients are commonly given pharmacological treatment, but the available treatments are not sufficiently effective. The development of sustained-release drug delivery systems (DDSs) for OA may be an attractive strategy to prevent rapid drug clearance and improve the half-life of a drug at the joint cavity. Such delivery systems will improve the therapeutic effects of anti-inflammatory effects in the joint cavity. Whereas, for disease-modifying OA drugs (DMOADs) which target chondrocytes or act on mesenchymal stem cells (MSCs), the cartilage-permeable DDSs are required to maximize their efficacy. This review provides an overview of joint structure in healthy and pathological conditions, introduces the advances of the sustained-release DDSs and the permeable DDSs, and discusses the rational design of the permeable DDSs for OA treatment. We hope that the ideas generated in this review will promote the development of effective OA drugs in the future.     

Spray-on transdermal drug delivery systems

Introduction: Transdermal drug delivery possesses superior advantages over other routes of administration, particularly minimizing first-pass metabolism. Transdermal drug delivery is challenged by the barrier nature of skin. Numerous technologies have been developed to overcome the relatively low skin permeability, including spray-on transdermal systems.

Areas covered: A transdermal spray-on system (TSS) usually consists of a solution containing the drug, a volatile solvent and in many cases a chemical penetration enhancer. TSS promotes drug delivery via the complex interplay between solvent evaporation and drug–solvent drag into skin. The volatile solvent carries the drug into the upper layers of the stratum corneum, and as the volatile solvent evaporates, an increase in the thermodynamic activity of the drug occurs resulting in an increased drug loading in skin.

Expert opinion: TSS is easily applied, delivering flexible drug dosage and associated with lower incidence of skin irritation. TSS provides a fast-drying product where the volatile solvent enables uniform drug distribution with minimal vehicle deposition on skin. TSS ensures precise dose administration that is aesthetically appealing and eliminates concerns of residual drug associated with transdermal patches. Furthermore, it provides a better alternative to traditional transdermal products due to ease of product development and manufacturing.