阿司匹林包合物的拉曼光谱和红外光谱研究

目的:通过拉曼光谱和红外光谱法分析阿司匹林包合物,探索拉曼光谱法作为一种新的验证包合物形成方法的可行性。方法:通过共聚焦拉曼光谱仪和傅里叶红外光谱仪分别测定并获得β-环糊精、阿司匹林、β-环糊精和阿司匹林物理混合物、阿司匹林包合物的拉曼图谱和红外图谱并将其进行对照分析。结果:在红外图谱和拉曼图谱中,阿司匹林的一些特征峰在其包合物中发生了位移,部分峰强发生变化甚至消失。结论:拉曼光谱和红外光谱同时表明,阿司匹林通过氢键作用嵌入β-环糊精的疏水空腔形成了包合物,其苯环结构、羰基结构和酯基结构被包裹于β-环糊精的空腔结构中。     

罗望子多糖硒酸酯的制备及表征

目的:合成罗望子多糖硒酸酯,并表征其结构特征。方法:在HNO3-BaCl2催化作用下,利用亚硒酸钠合成罗望子多糖硒酸酯,以硒含量为指标对合成工艺进行优选,采用红外吸收光谱、热重分析、GPC等方法对合成产物进行表征。结果:罗望子多糖硒酸酯最佳合成条件为硝酸浓度为0.5%,反应温度80℃,反应时间14 h,此条件下产物硒含量约为22 mg.g-1,结论:合成产物中硒以Se=O的形式存在,且与纯多糖比较,多糖硒酸酯热稳定性和相对分子质量稍有降低,可能是由于酸性反应体系下罗望子多糖稍有降解,同时引入的亚硒酸基对分子结构产生了影响。     

Carbon nanotubes for biomedical imaging: The recent advances

This article reviews the latest progresses regarding the applications of carbon nanotubes (CNTs), including single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs), as multifunctional nano-probes for biomedical imaging. Utilizing the intrinsic band-gap fluorescence of semi-conducting single-walled carbon nanotubes (SWNTs), fluorescence imaging in the near infrared II (NIR-II) region with enhanced tissue penetration and spatial resolution has shown great promise in recent years. Raman imaging based on the resonance Raman scattering of SWNTs has also been explored by a number of groups for in vitro and in vivo imaging of biological samples. The strong absorbance of CNTs in the NIR region can be used for photoacoustic imaging, and their photoacoustic signals can be dramatically enhanced by adding organic dyes, or coating with gold shells. Taking advantages of metal nanoparticle impurities attached to nanotubes, CNTs can also serve as a T2-contrast agent in magnetic resonance (MR) imaging. In addition, when labeled with radioactive isotopes, many groups have developed nuclear imaging with functionalized CNTs. Therefore CNTs are unique imaging probes with great potential in biomedical multimodal imaging.     

Applications of Fourier transform infrared spectroscopic imaging to tablet dissolution and drug release

Introduction: Solid oral dosage forms are the most commonly used method for administering active pharmaceutical ingredients to patients. Understanding the mechanisms and processes of drug release is essential for improving the design of pharmaceutical tablets.

Areas covered: In this review, recent approaches where attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic imaging has been applied to study tablet dissolution and drug release have been investigated. Drug release studies of model pharmaceutical systems composed of drug/polymer mixtures in the presence of aqueous solutions have been discussed, as has the subsequent combination with UV/Vis spectroscopic detection to quantify the amount of drug dissolved as a function of time. The use of a single-reflection ATR accessory with a diamond crystal allows for in situ FTIR imaging of tablet compaction and dissolution.

Expert opinion: ATR-FTIR imaging can address the challenges of investigating the mechanisms of drug release from a range of innovative new delivery systems. Unlike standard dissolution tests, this spectroscopic imaging method obtains insight and information about changes within the tablet during dissolution. Areas where ATR-FTIR imaging has shown further potential to be particularly useful are for the study of multi-layered solid tablets, high-throughput analysis, use of microfluidic devices and for surface-enhanced ATR-FTIR spectroscopy.     

Alginate coated chitosan core shell nanoparticles for oral delivery of enoxaparin: In vitro and in vivo assessment

The objective of present research work was to develop alginate coated chitosan core shell nanoparticles (Alg-CS-NPs) for oral delivery of low molecular weight heparin, enoxaparin. Chitosan nanoparticles (CS-NPs) were synthesized by ionic gelation of chitosan using sodium tripolyphosphate. Core shell nanoparticles were prepared by coating CS-NPs with alginate solution under mild agitation. The Alg-CS-NPs were characterized for surface morphology, surface coating, particle size, polydispersity index, zeta potential, drug loading and entrapment efficiency using SEM, Zeta-sizer, FTIR and DSC techniques. Alginate coating increased the size of optimized chitosan nanoparticles from around 213 nm to about 335 nm as measured by dynamic light scattering in zeta sizer and further confirmed by SEM analysis. The performance of optimized enoxaparin loaded Alg-CS-NPs was evaluated by in vitro drug release studies, in vitro permeation study across intestinal epithelium, in vivo venous thrombosis model, particulate uptake by intestinal epithelium using fluorescence microscopy and pharmacokinetic studies in rats. Coating of alginate over the CS-NPs improved the release profile of enoxaparin from the nanoparticles for successful oral delivery. In vitro permeation studies elucidated that more than 75% enoxaparin permeated across the intestinal epithelium with Alg-CS-NPs. The Alg-CS-NPs significantly increased (p < 0.05) the oral bioavailability of enoxaparin in comparison to plain enoxaparin solution as revealed by threefold increase in AUC of plasma drug concentration time curve and around 60% reduction in thrombus formation in rat venous thrombosis model. The core shell Alg-CS-NPs showed promising potential for oral delivery and significantly enhanced the in vivo oral absorption of enoxaparin.     

绞股蓝水分近红外定量模型的建立

目的:运用近红外光谱技术对绞股蓝药材中水分进行快速测定。方法:采集不同产地不同批号绞股蓝样品的近红外光谱图,结合TQ Analyst 8.0软件,将其经一阶导数及Norris平滑(有效位数3,有效位间间隔3)预处理,在10 000~4 000cm-1谱段内,选择前10个主成分,采用偏最小二乘法建立绞股蓝水分近红外光定量模型。结果:所建模型相关系数r=0.9688,交叉验证均方根偏差(RMSECV)=0.303,预测均方根偏差(RMSEP)=0.284,验证集预测回收率为101.14%(n=11),RSD2.16%,并且仪器精密度良好,样品重复性佳,在2 h内样品检测稳定。结论:该研究所建立的模型性能较好,绞股蓝水分含量测定较准确。可以应用于绞股蓝药材水分的快速测定。     

盐析法制备小檗碱壳聚糖纳米载药微球

目的：探索制备小檗碱壳聚糖载药纳米微球颗粒的新方法及关键技术。方法：采用盐析法,通过三聚磷酸钠交联制备小檗碱壳聚糖纳米载药微球,测定载药微球的包封率,观察其扫描电镜图及红外光谱。结果：小檗碱颗粒粒径分布于400~500 nm,经壳聚糖包裹的小檗碱纳米颗粒形状规则,具有核-壳结构,平均粒径约500 nm,包封率约70%。结论：壳聚糖包裹的小檗碱颗粒具有均一的纳米粒径和良好的包封率,为小檗碱缓释用药和靶向给药设计提供参考。     

Evaluation of the wound healing activity of Shorea robusta, an Indian ethnomedicine,and its isolated constituent(s) in topical formulation

Ethnopharmacological relevance

Different parts of Indian ethnomedicinal plant Shorea robusta is traditionally used for several ailments including wounds and burn by different tribal groups, since ages. Here we have validated, for the first time, the effectiveness and the possible mechanism of action of young leaf extracts of Shorea robusta, used by two distinct tribes of India, and its isolated compounds as a topical formulation in three wound models in rats.

Materials and methods

Bioactivity-guided study of the active extract resulted in the isolation of two known compounds. The prepared ointment containing extracts (2.5 and 5%, w/w), fractions (5% w/w) and isolated compounds (0.25% w/w) were evaluated on excision, incision and dead space wound models in rats by the rate of wound closure, period of epithelialisation, tensile strength, granulation tissue weight, hydroxyproline content and histopathology.

Results

The animals treated with the extracts and fractions (5%) showed significant reduction in wound area 96.55 and 96.41% with faster epithelialisation (17.50 and 17.86), while the isolated compounds bergenin and ursolic acid heal the wound faster, but complete epithelialisation with 100% wound contraction was evident with 5% povidone–iodine group on 18th post-wounding day. Moreover, the tensile strength of incision wound, granuloma tissue weight, and hydroxyproline content was significantly increased in both the extract and compound(s) treated animals. Furthermore, the tissue histology of animals treated with the isolated compound(s) showed complete epithelialisation with increased collagenation, similar to povidone–iodine group.

Conclusion

Thus, our results validated the traditional use of Shorea robusta young leaves in wound management.