Design and In Vitro Evaluation of Solid-Lipid Nanoparticle Drug Delivery for Aceclofenac

Solid-lipid nanoparticles (SLNs) are an interesting nanoparticulate delivery system. The present work was carried out with the aim to develop a prolonged release solid-lipid nanoparticulate system for the drug using aceclofenac. Aceclofenac-loaded solid-lipid nanoparticles (ACSLNs) was prepared by hot high pressure homogenization technique. Tripalmitin was used as the lipid core. Surfactants (Poloxamer 188, Tween 80, and soya lecithin) and co-surfactant (sodium tauro glycholate) were used in the formulations. The prepared ACSLN formulations were characterized for encapsulation efficiency (EE), photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), and x-ray diffraction (XRD). From these studies, mean particle diameter of the formulation prepared with combination of surfactants (Poloxmer 188 and Tween 80) was about 200 nm with spherical morphology and amorphous nature. Higher EE was obtained with SLNs prepared using combination of soya lecithin and poloxmer 188. The organization and distribution of the ingredients in the nanoparticulate system were studied by differential scanning calorimetry (DSC) and the results showed that the drug is incorporated into the solid matrix. The prepared formulations demonstrated favorable in vitro prolonged release characteristics. Experimental in vitro release data were substituted in available mathematical models to establish the release kinetics of ACSLNs and it was found to follow first-order kinetics and Higuchi diffusion mechanism. Our results suggest that these SLN formulations could constitute a promising approach for the drug delivery of aceclofenac.     

增溶性辅料泊洛沙姆188与胆酸聚集形态的介观模拟

为了建立符合中药特点的增溶性药用辅料的筛选与评价方法,本研究以清开灵注射液为研究载体,采用介观动力学方法(MesoDyn)研究其难溶活性成分胆酸与增溶性辅料泊洛沙姆188之间的相互作用,探讨了胆酸对泊洛沙姆188临界胶束浓度的影响及泊洛沙姆188浓度、模拟时间、温度对两者聚集体构型的影响,并采用实验方法验证了部分模拟结果,为中药注射剂增溶性辅料的科学应用提供一定基础.结果表明:在清开灵注射液中活性成分胆酸的存在下,泊洛沙姆188的临界胶束浓度范围为0.6%～0.7%,降低了泊洛沙姆188自身的临界胶束浓度,为使清开灵注射液中的胆酸(3%)全部增溶,泊洛沙姆188浓度应为1.7%.     

Verteilungskoeffizienten von Ag,In, Re,Au, Hg,Tl, Pb und Bi in Salpetersäure-Methanol-Gemischen

Der Anionenaustausch unter Verwendung von Salpetersäure-Methanol-Gemischen ist in den letzten Jahren von einer Anzahl von Autoren untersucht worden [1, 2, 3, 4]. In einer früheren Arbeit hatten wir bereits auf seine praktisehc Anwendbarkeit für die Trennung der SK hingewiescn [5]. In der vorliegenden Arbeit werden von uns die Verteilungs-koeffizienten von Ag, In, Re, Au, Hg, Tl, Pb und Bi angegeben und Beispiele für mögliche Trennungen angeführt.     

β-榄香烯三羰基铼配合物的合成、放射化学合成及抗癌活性研究

以中草药有效成分β-榄香烯为起始原料, 经烯丙位的氯代反应及亲核取代反应在β-榄香烯母体上成功地引入含吡啶基的三齿螯合剂, 并与稳定的三羰基铼配位, 得到了一种新的铼(I)三齿配合物, 在此基础上利用铼的放射性同位素Re-188进行了放射性标记. 反应中间体及最终化合物分别用IR, ¹H NMR, HRMS, HPLC或元素分析进行表征, 并对该化合物进行了初步的体外抗癌活性研究. β-榄香烯三羰基铼配合物的合成、放射化学合成及体外抗癌活性评价, 为探讨β-榄香烯体内靶点和作用机制提供了可能, 并为最终开发基于β-榄香烯的放射性药物奠定了基础.     

186Os和188Os双同位素溶液的制备及其中Os同位素丰度与含量的标定

在核反应堆中辐照高纯铼金属带 ,185Re和187Re通过 (n ,γ)反应后 ,经 β衰变产生186Os和188Os ,用H2 O2 和H2 SO4 将Re带溶解并同时将186Os和188Os蒸馏出 ,首先用 2 0 %NaOH溶液吸收 ,然后再将碱吸收液重新蒸馏 ,最后将186Os和188Os混合同位素保存在 2 5 %HCl介质中 ,用负离子热电离质谱仪 (NTIMS)标定其含量及同位素丰度。结果表明 ,91.4mg的高纯铼金属带 ,在辐照的累积通量为 1.32× 10 18n/cm2时 ,可产生Os 8.46 μg ,其186Os和188Os的同位素丰度分别为 6 0 .89%和 38.6 3%     

Tissue Distribution Study of Poloxamer188 in Rats by Ultra-High-Performance Liquid Chromatography Quadrupole Time of Flight/Mass Spectrometry with MSALL-Based Approach

Poloxamer188 (PL188), as one of the most commonly used pharmaceutical excipients, has unique physicochemical properties and good biocompatibility, and so is playing an increasingly extensive role in the field of medicine. Currently, there are few studies on the tissue distribution of PL188 in vivo. In this study, the LC-MS method based on MS^ALL technique of quadrupole time of flight mass spectrometry for absolute quantitative analysis of poloxamer 188 in biological substrates was established for the first time. The tissue distribution of poloxamer188 in SD rats were studied using the established quantitative analysis method. To explore the distribution of PL188 in organs and tissues, PL188 was administered via rat tail vein at a dose of 5 mg/kg. Eight kinds of tissues including heart, liver, spleen, lung, kidney, stomach, muscle and brain of rats were collected at 0.25 h, 1 h and 4 h after administration. Tissue distributions showed the highest level was observed in kidney, then in stomach, which indicated PL188 mainly bioaccumulated in the kidney. This study can provide references for the further study of PL188.     

Selective dehydrogenation of isopropyl alcohol on low-percentage supported bimetallic rhenium-containing catalysts

The activity and selectivity of mono-and bimetallic sibunite-supported Re-, Cu-, Ni-, and Pd-containing catalysts in dehydrogenation of isopropyl alcohol to acetone (T=200–275 °C,v=1.1h⁻¹) were studied. The bimetallic Re, Cu-, Re, Ni-, and Re, Pd-catalysts containing 1 or 2% of the metal possess the higher activity and stability than monometallic catalysts. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2381–2383, November, 1998.     

[~(188)Re(CO)_3(H_2O)_3]~+前体及标记药盒的制备

~(186,188)Re具有优良的核素性质,是放射性治疗药物的首选核素之一~([1]).~(186,188)Re广泛用于有机小分子化合物,单抗(McAb)、单抗片段(Fab)、受体配基和生物小分子肽,以达到靶向治疗的目的~([2-3]).铼的化学性质与锝极其相似,在标记前以~(188)ReO_4~-形式存在,在标记药物中呈低价态.制备时常规方法是将七价铼通过亚锡法还原到五价~([4-5]).     

Properties and structure of copper ultraphosphate glasses

The structures of xCuO · (1 − x)P₂O₅ glasses (0 ? x ? 0.50) prepared in vacuum sealed silica ampoules were investigated using vibrational spectroscopies. With the addition of CuO, both infrared and Raman spectra indicate a systematic transformation from a three-dimensional ultraphosphate network dominated by Q³ tetrahedra into a chain-like metaphosphate structure dominated by Q² tetrahedra. IR spectra clearly show two distinct Q³ sites with bands at 1378 and 1306 cm⁻¹, assigned to PO bonds on isolated Q³ tetrahedra and PO bonds on tetrahedra that participate in the coordination environments of the Cu-octahedra, respectively. As CuO content increases, the intensity of the PO band associated with the tetrahedra increases to a maximum x ∼ 0.33, then decreases with a concomitant increase of the intensity of the band at 1265 cm⁻¹, due to the asymmetric vibration of the PO₂ groups on Q² tetrahedra. When x > 0.33 the isolated Cu-octahedra begin to share common oxygens to form a sub-network in the phosphate matrix. The effects of glass structure on the glass properties, including density, refractive index, and glass transition temperature, are discussed.     

Buchbesprechungen

1. Einlcitung

Die Entwieklung der modernen Radiochemie und analytisehen Chemie ist mit der Notwendigkeit der Ausarbeitung nciicr Expreßmethoden zur Trennung und Analyse von Elementen mit ähnlichen chemischen Eigenschaften verbunden. Eine der aussichtsreichsten Methoden ist die Ionenelektrofokussierung, die in der Fachliteratur auch als fokussierender lonenaustausch oder elektrophoretisehe Ionenfokussierung bezeiehnet wird. Die Prinzipien diescr Methode sind von Schumacher, Kiso, Gijbels sowie von Schwedow und Mitarbeitern entwickelt worden [1-4].

Die Ionenelektrofokussierung beruht auf der Ausnutzung eines Gegenstroms von Kationen und Konipiexanionen der zu trennenden Elemente in einem Konzentrationsgradienten des Komplexbildners und pH-Gradienten der Lösung längs des elektrisehen Feldes. Der Vorzug dieser Methode gegenüber den anderen Elcktromigrationsniethoden liegt in der kurzercn Versuehsdauer.

Das Ziel der vorliegenden Untersuchungen bestand darin, eine Trennmethode für Morybdän und Rhenium auf der Grundlage der Ionenelektrofokussierung aiiszuarbeiten.