氯硝柳胺衍生物的透皮控释给药研究

透皮给药;药物控释;氯硝柳胺衍生物的透皮控释给药研究     

磁性铁氧化物纳米粒子在药剂学上的应用

磁性铁氧化物纳米粒子(MIONPs)是近几十年发展起来的一种具有磁靶向性的纳米材料,其以良好的磁靶向性、小尺寸效应、生物相容性等特点在生物医学领域具有很好的应用前景,尤其在药剂学领域的应用已经成为一个重要的研究方向。本文在总结近年来国内外有关多功能MIONPs研究成果的基础上,阐述了各种铁氧化物纳米粒子在药剂学领域的应用,主要包括MIONPs的智能载药靶向控释、对特殊药物的靶向负载、降低身体的多药耐药性(MDR)、加强药物治疗效果、载药穿透血脑屏障(BBB)等;并讨论了当前应用中的优点和不足。最后,展望了其在药物、药剂学领域的应用前景并指出了一些亟待解决的问题。     

聚合物纳米粒应用于透皮给药及促渗机制研究进展

透皮给药系统因具有避免肝脏首过效应、血药浓度稳定、局部靶向性及给药方便等优势而备受青睐。然而角质层作为一种生物屏障限制了很多药物,特别是亲水性药物的经皮渗透,因此采用有效的方法促进药物经皮渗透成为透皮给药的关键。聚合物纳米粒因具有药物包封率高、减小酶降解、可控释性能好、比表面积大等优势,易于在皮肤表面富集,从而促进药物渗透,其作为药物载体用于透皮给药逐渐成为近几年的研究热点。本文综述了近年来纳米粒在促进药物渗透方面的研究进展,包括纳米粒促进药物渗透的机制,以及纳米粒联合主动透皮给药方式在促进药物经皮渗透中的应用,并对研究中存在的问题提出适当建议。     

多功能脂质体递药系统

脂质体是第一种成功进入临床应用,也是目前进入临床应用最多的一类纳米递药体系,将药物装载于脂质体中可以实现降低非特异性吸收、提高靶组织的富集量、降低副作用等目的。但是当前的脂质体技术仍然存在着诸多缺陷,例如载药量低以及靶向效果差等。新的脂质体载药技术的发展使得脂质体的载药量和包封率有了很大的提升。将热、激光、超声、离子辐射等外源物理刺激与脂质体药物结合可以提高脂质体药物在肿瘤的富集量,同时调节药物的释放。脂质体独特的核壳结构使得脂质体可以同时装载多种药物从而实现联合给药,通过合理设计脂质体纳米材料的结构不仅能够实现多种药物的递送,还能够实现药物的程序性释放。脂质体不仅能够装载治疗性药物,还能装载具有造影功能的组分,从而实现对治疗过程的影像监控。本文将主要介绍近五年在脂质体的载药方法、靶向给药、药物控释、联合给药、影像可视化等方面的一些重要进展。     

聚乙二醇在新型药物制剂中的应用

聚乙二醇具有良好的生物相容性和两亲性 ,在生物医药领域中有着广泛的应用 ,本文就聚乙二醇在新型药物制剂中的应用进行综述 ,主要包括纳米给药系统、蛋白质药物修饰和疏水性药物的前药等。     

刺激响应聚合物微针在经皮给药中的应用

聚合物微针自身具有良好的机械性能和优异的生物相容性,能以微创的方式刺穿皮肤角质层,实现药物的高效经皮吸收,从而有效治疗各种疾病,如糖尿病、癌症、肥胖以及眼部疾病等.如何调控聚合物微针中负载药物的释放行为,是微针经皮给药需要关注的核心要素.刺激响应释放聚合物微针作为一种新兴的按需给药技术,能根据外界环境条件或自身生理环境...     

甲壳胺药膜的控制释放研究

以阿司匹林为模型药物研究了小分子药物在甲壳腹膜中的释放行为，结果表明释放是扩散控制的，与膜厚、介质pH值，膜交联度及膜分散性密切相关。改变这些参数可达到比较恒定的延长释放和不同的给药途径。     

蛋白类药物口服药剂的设计与稳定性研究

口服给药具有方便、安全、患者依存性强等优势,是理想的给药途径,但蛋白类药物在口服过程中易被胃酸及蛋白酶分解而失活,导致生物利用度较低.本实验设计了一种药物载体,用于蛋白类药物口服给药,解决了蛋白类药物在胃肠道中易失活的问题.以葡萄糖氧化酶为蛋白药物模型,通过在蛋白质表面原位自由基聚合反应制备葡萄糖氧化酶纳米微囊,低温干...     

盐酸维拉帕米药物树脂复合物的制备及其体外释药动力学

口服药物树脂控释给药系统;交换反应动力学;盐酸维拉帕米药物树脂复合物的制备及其体外释药动力学     

血脑屏障通透性增效方法的研究进展

血脑屏障作为脑部的屏障系统,具有较强的保护作用,维持着中枢神经系统的内环境的稳定,同时也阻止药物进入脑部治疗中枢神经系统疾病。多年来,在提高血脑屏障通透性的研究方面有了很大进展,让药物靶向入脑,为治疗中枢神经系统疾病提供了很大的帮助。本文系统介绍血脑屏障的结构,其中主要介绍产生血脑屏障的解剖和功能结构,并对提高其通透性的增效方法和机制进行了概括,主要从物理、化学、生物学和纳米给药载体等方面阐述了提高血脑屏障透过方式,并简要介绍了一些具体药物的输送的应用。     

Ion Exchange Controlled Drug Release from Polymerized Ionic Liquids

In this work ion functionalized hydrogels as potent drug delivery systems are presented. The ion functionalization of the hydrogel enables the retention of ionic drug molecules and thus a reduction of burst release effects. Timolol maleate in combination with polymerized anionic 3‐sulfopropylmethacrylate potassium and ibuprofen combined with cationic poly‐[2‐(methacryloyloxy)ethyl] trimethylammonium chloride are investigated in respect to their drug release profile. The results are showing an ion exchange depending release behavior instead of a diffusion‐controlled drug release as it is known from common drug delivery systems. Furthermore, the suitability of such hydrogels for standard methods for sterilization is investigated.     

Ion Exchange Extraction of Boron from Aqueous Fluids by Amberlite IRA 743 Resin

The ion exchange characteristics d Amherlite IRA 743 resin for extracting boron from aqueous fluids have been investigated in detail. The results show that AmherHte IRA 743 resin, a boron specific ion exchange resin, can quantitatively extract boron as the B (OH)4- spedes from weakly basle solution. Some exchangeable anions such as CI- and SO4^2- are present, resulting in an increase in pH value of the loeded solution within the nan, and the boron in natural aqueous fluids with low nH is also extracted by Amberlite IRA 743 resin. However, the voiume of loaded solution must be restricted. The maximum voiume of loaded solution giving quantitative extraction of boron decreases for sample soh.,tiom of lower pH value. Warm HCI solution is more effective than room temperature HCI solution for eluting boron from Amberllte IRA 743 resin.     

Preparation and characterization of a novel pH-sensitive ion exchange resin

Methylacrylic acid/styrene cross-linked with divinylbenzene is a novel pH-sensitive ion exchange resin. Microspheres of this resin were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The microspheres showed a pulsatile swelling behavior when the pH of the media changed. The pH-sensitive microspheres were loaded with salbutamol sulfate and the drug-release characteristics were studied under both simulated gastric and intestinal pH conditions. The results obtained showed that the drug release also depended on the pH of the release media.     

Confinement and controlled release of quinine on chitosan–montmorillonite bionanocomposites

To accomplish the controlled‐release systems based on layered clay minerals, one of the best ways is to intercalate organic molecules into the interlayer gallery of clay minerals. Into a series of chitosan (CS) intercalated montmorillonite (MMT) nanocomposites, prepared via ion‐exchange route, antimalarial drug [quinine (QUI)] was loaded to act as effective drug delivery systems. Among the CS–MMT nanocomposites, higher drug adsorption with decreasing CS concentration was observed. CS–MMT and CS–MMT/QUI intercalated compounds were characterized by powder X‐ray diffraction, Fourier transform infrared spectroscopy, and thermal analysis. The synthesized nanocomposites, filled in the gelatin capsules followed by coating of Eudragit® L 100, were tested for in vitro drug release performance in the sequential buffer environments at 37 ± 0.5 °C. As no drug release (0%) was observed in the gastric fluid, the coating of Eudragit® L 100 to the capsules is highly adequate. However, the drug release rate was comparatively faster from the CS intercalated clay with compare with pure clay. The drug release kinetic data revealed that the release of QUI from the nanocomposites can be explained by modified Freundlich model. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Polymeric Micelles for Multidrug Delivery and Combination Therapy

The use of conventional therapy based on a single therapeutic agent is not optimal to treat human diseases. The concept called “combination therapy”, based on simultaneous administration of multiple therapeutics is recognized as a more efficient solution. Interestingly, this concept has been in use since ancient times in traditional herbal remedies with drug combinations, despite mechanisms of these therapeutics not fully comprehended by scientists. This idea has been recently re‐enacted in modern scenarios with the introduction of polymeric micelles loaded with several drugs as multidrug nanocarriers. This Concept article presents current research and developments on the application of polymeric micelles for multidrug delivery and combination therapy. The principles of micelle formation, their structure, and the developments and concept of multidrug delivery are introduced, followed by discussion on recent advances of multidrug delivery concepts directed towards targeted drug delivery and cancer, gene, and RNA therapies. The advantages of various polymeric micelles designed for different applications, and new developments combined with diagnostics and imaging are elucidated. A compilation work from our group based on multidrug‐loaded micelles as carriers in drug‐releasing implants for local delivery systems based on titania nanotubes is summarized. Finally, an overview of recent developments and prospective outlook for future trends in this field is given.     

Calcium Phosphate Nanocarriers Dual‐Loaded with Bovine Serum Albumin and Ibuprofen: Facile Synthesis,Sequential Drug Loading and Sustained Drug Release

A simple and green strategy is reported for the preparation, drug loading, and release properties of a drug delivery system consisting of calcium phosphate (CP) nanocarriers dual‐loaded with bovine serum albumin (BSA) and hydrophobic drug ibuprofen (IBU). The sequential loading of BSA and IBU in calcium phosphate nanocarriers and in vitro simultaneous release of BSA and IBU are realized and investigated. In this method, BSA, which is used as a model protein drug, is encapsulated in situ in calcium phosphate nanocarriers. Subsequently, the typical hydrophobic drug IBU is loaded in the BSA/CP drug delivery system, forming the IBU/BSA/CP dual drug delivery system. The experiments reveal that the preloaded BSA not only reduces the cytotoxicity of calcium phosphate nanocarriers but also significantly improves the IBU drug loading capacity in calcium phosphate nanocarriers and greatly extends the duration of drug release. Thus, the as‐prepared IBU/BSA/CP dual drug delivery system is promising for drug delivery applications.     

离子交换树脂控制药物释放研究进展

离子交换树脂是一类功能高分子聚合物，长期以来应用于分析化学、蛋白质化学、纯水制备等领域。本文对离子交换树脂释药系统的设计原理、制备方法及释药机制和特点作了详细叙述，并介绍了该释药系统在口服药物树脂液体控释制剂、药物树脂缓释胶囊及靶向给药系统上的应用。     

RECOVERY OF URANIURN FROM CARBONATE SOLUTIONS USING STRONGLY BASIC ANION EXCHANGER 3．THE MECHANISMS OF RECOVERY PROCESSES

A moving boundary model under considering the volume change of spherical resin beads during ion exchange processes was employed to recognize the mechanisms of reecovering uranium from carbonate solutions using strongly basic anion exchanger.Two important factors,swelling and ion exchange,which directly affect the violume of ion exchangers were taken into account.An ion exchange mechanism has been found for the forward reaction PCl/[UO2(CO3)3]^4-,and is partical diffusion governing at high concentration of the complex anion.The mechanism of RCl/U(VI) at pH 5.5-7.5 is a chemical reaction taking place at the moving boundary of the unreacted nucleus.For the reverse reaction RnU/NaCl,the uranyl tricarbonate complex anion in the resin phase is replaced by Cl^- ions with an ion exchange mechanism alway determined by particle diffusion.The other forms of uranium in the solid phase loaded on the resin at pH5.5-7.5 should belong to non-exchangeable uranium.The mechanism of the reverse reaction RnU/HCl is always chemical reaction which is not restricted to the moving boundary of the unreacted core.     

Use of x-ray fluorescence spectrometry in ion-exchange studies of leach liquors

Equilibrium and kinetic studies of ion exchange of a complex leach liquor from coal ash, with strongly basic resins and a liquid ion exchanger are reported. The multi-component system was studied by determining the composition of the effluents and by non-destructive analysis of the loaded ion exchangers by XRF spectrometry. In the case of column operation, the elution processes were investigated by the same method, which was very appropriate for non-destructive monitoring of resin regeneration steps done repeatedly with the same resin sample.     

Controlled drug release studies of atenolol using differently sulfonated acryloxyacetophenone and methyl methacrylate copolymer resins as drug carriers

2-Acryloxyacetophenone(AAP) was prepared and subjected to suspension polymerization with methyl methacrylate(MMA) using azobisisobutyronitrile(AIBN) as free radical initiator.The differently sulfonated AAP-MMA cross-linked copolymer cationic exchange resins were prepared by sulfonation with concentrated sulphuric acid at 70 °C.Several characteristics of the prepared resins were evaluated,i.e.FTIR,the ion-exchange capacity(IEC),thermo gravimetric analysis(TGA),particle size distribution and microscopic morphology.The resin characteristics were altered with degree of sulfonation,providing that differently sulfonated resins could be prepared.The behavior of atenolol(ATL) loading and in vitro release in the USP stimulated gastric and intestinal fluids of the obtained resins were evaluated.The drug loaded in the resin increased with increasing degree of sulfonation and hence the drug binding site in resin employed.The drug release was lower from the resins with higher content of sulfonic group due to the increase in the diffusive path depth.The drug release was a little lower in stimulated gastric fluid(SGF) than in stimulated intestinal fluids(SIF).The basic groups,ionized to a little greater extent in SGF and preferred binding with the resin rather than releasing.Hence,the differently sulfonated resins could be utilized as novel carriers for drug delivery.