膨润土对药用混悬液助悬性能的考察

本文报道了无机胶体膨润土(Bentonite)作为助悬剂在炉甘石洗剂中的应用,并与有机助悬剂及另一种无机胶体XVT—M进行比较,显示了其优异的助悬性能。     

膨润土对阿司匹林致小鼠胃黏膜损伤模型的保护作用

目的探讨膨润土对胃黏膜损伤的保护作用,为开发该药物制剂奠定基础。方法采用阿司匹林诱发小鼠胃黏膜损伤模型,观察胃黏膜损伤程度并计算溃疡指数;做胃组织病理学检查;测定血清中丙二醛（MDA）的含量、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Vx）的活力;并测定胃内容物pH值;应用阿利斯蓝染色法测定胃壁结合黏液量。结果通过病理检查和生化指标检测可知,当膨润土的剂量为50mg·kg-1时,就可对模型小鼠的胃黏膜产生一定的保护作用,当膨润土剂量达200-300mg·kg-1时,可明显改善胃黏膜损伤,抑制胃黏膜MDA的生成,恢复SOD和GSH-Px活性,且可使胃黏膜的黏液量明显增加,但对胃内容物的pH值无明显的影响。结论膨润土剂量为200～300mg·kg-1时,对阿司匹林致小鼠胃黏膜损伤模型具有明显的保护作用。     

几种助悬剂对复方硫洗剂助悬性能的考察

目的：将3种常用助悬剂及膨润土用于复方硫洗剂,选择最佳悬剂。方法：用动力学、流变学的方法考察不同复方硫洗剂的稳定剂。结果：西黄著的助悬效果好且有触变性,膨润土使制剂的稳定性增加,但触变性有所改变,与苯扎溴铵合用后助悬性能增强,结论：西黄著胶,膨润土＋苯扎溴铵是复方硫洗剂的理想助悬剂。     

几种助悬剂对复方硫洗剂助悬性能的考察

目的 :选择复方硫洗剂的最佳助悬剂。方法 :用动力学、流变学的方法考察选用不同助悬剂的复方硫洗剂的稳定性。结果 :西黄蓍胶的助悬效果好且有触变性 ;膨润土使制剂的稳定性增加 ,但触变性有所改变 ,与新洁尔灭合用后助悬性能增强。结论 :西黄蓍胶和膨润土 +新洁尔灭是复方硫洗剂的理想助悬剂     

蒙脱石作为药物载体的研究进展

天然蒙脱石是一种由膨润土提纯而来的非金属矿物,是一种2∶1型的粘土矿,即两个硅氧四面体亚层中间夹一个铝氧八面体亚层。该单位晶胞结构使其在医药领域的应用中具有独特的优势。蒙脱石作为一种性能良好的药用辅料,可应用于新型药物载体的开发,将有助于设计药物新剂型和寻找适宜的给药途径。本文综述了蒙脱石作为药物载体应用于医药领域的国内外最新研究进展。     

酶解-吸附澄清法提取水辣蓼总黄酮的工艺优化

目的 优化酶解-吸附澄清法提取水辣蓼总黄酮的工艺.方法 采用响应面法,构建多元二次回归数学模型,筛选酶法提取和絮凝澄清的最佳工艺条件.结果 最佳酶法提取工艺为料液比1∶50,pH6.06,复合酶用量0.24％,酶解温度50℃,酶解时间1.62 h;最佳澄清工艺为酶解液的浓缩比1∶5,药液pH5.24,膨润土用量0.45 mL·g-1,43.43℃下絮凝40 min.结论 酶法提取条件温和,膨润土絮凝能有效降低酶解液中总固形物的含量,优于传统醇沉法.     

五味子果实和藤茎提取液脱色剂的筛选

目的:筛选适合五味子果实和藤茎提取液的脱色剂。方法:采用高效液相色谱法测定使用8种脱色剂(活性白土、活性炭、硅藻土、钙质膨润土、高岭土、活性氧化铝、氧化镁、凹凸棒土)对五味子果实和藤茎提取液脱色后4种木脂素成分(五味子醇甲、五味子醇乙、五味子甲素、五味子乙素)的含量,分别计算五味子果实和藤茎样品的脱色率和各木脂素成分的保留率。结果 :8种脱色剂对五味子果实和藤茎提取液的脱色效果大小依次为凹凸棒土>活性炭>活性氧化铝>高岭土>氧化镁>硅藻土>钙质膨润土>活性白土,活性炭>硅藻土>凹凸棒土>氧化镁>高岭土>活性氧化铝>活性白土>钙质膨润土;其中凹凸棒土和活性炭分别对五味子果实和藤茎提取液脱色效果最好,脱色率分别为60.47%、69.24%;对五味子醇甲、五味子醇乙、五味子甲素、五味子乙素的保留率分别为77.43%、77.73%、77.07%、77.53%和72.18%、70.17%、70.32%、70.28%。结论:在试验的8种脱色剂中,分别以凹凸棒土和活性炭对五味子果实和藤茎提取液的脱色效果最优。     

从甜叶菊中提取和回收甜味糖苷

US2006134292-A1将甜叶菊Stevia rebaudiana(Bert.)Bert.用热水处理,提取出一种含有混合的甜味糖苷的含水溶液,在提取期间用果胶酶酶解处理所得的提取物,将提取物与β-环糊精接触,用膨润土(bentonite)处理含水的提取物,最后浓缩所得的滤液至糖浆状或干燥状。本专利还详述了甜叶     

阿司匹林片成型工艺研究

目的优选阿司匹林片的成型工艺条件。方法采用单因素实验设计,以片剂外观、硬度和崩解时间等为考察指标,对成型工艺进行优选。结果确定最佳成型工艺为:阿司匹林0.1 g,钠基膨润土0.25 g和枸橼酸0.001 g,混匀后用乙醇制软材,20目筛制粒,50℃干燥,加入质量分数0.4%微粉硅胶,压片。结论优选得到的工艺稳定可行。     

基于SaaS模式的中小医院信息化建设初探

在介绍SaaS模式的基础上,分析中小医院应用SaaS的支撑条件,从SaaS应用医院的角度和社会的角度对SaaS应用的效益进行了分析,分析了SaaS成功应用的关键因素,提出了中小医院SaaS应用的一般步骤,作为对我国中小医院的医院信息化进行一些初步的探索。     

Cellular uptake and cytotoxic potential of respirable bentonite particles with different quartz contents and chemical modifications in human lung fibroblasts

Considering the biological reactivity of pure quartz in lung cells, there is a strong interest to clarify the cellular effects of respirable siliceous dusts, like bentonites. In the present study, we investigated the cellular uptake and the cytotoxic potential of bentonite particles (Ø< 10 μm) with an α-quartz content of up to 6% and different chemical modifications (activation: alkaline, acidic, organic) in human lung fibroblasts (IMR90). Additionally, the ability of the particles to induce apoptosis in IMR90-cells and the hemolytic activity was tested. All bentonite samples were tested for endotoxins with the in vitro-Pyrogen test and were found to be negative. Cellular uptake of particles by IMR90-cells was studied by transmission electron microscopy (TEM). Cytotoxicity was analyzed in IMR90-cells by determination of viable cells using flow cytometry and by measuring of the cell respiratory activity. Induced apoptotic cells were detected by AnnexinV/Propidiumiodide-staining and gel electrophoresis. Our results demonstrate that activated bentonite particles are better taken up by IMR90-cells than untreated (native) bentonite particles. Also, activated bentonite particles with a quartz content of 5–6% were more cytotoxic than untreated bentonites or bentonites with a quartz content lower than 4%. The bentonite samples induced necrotic as well as apoptotic cell death. In general, bentonites showed a high membrane-damaging potential shown as hemolytic activity in human erythrocytes. We conclude that cellular effects of bentonite particles in human lung cells are enhanced after chemical treatment of the particles. The cytotoxic potential of the different bentonites is primarily characterized by a strong lysis of the cell membrane.     

Controlled flocculation of coarse suspensions by colloidally dispersed solids I: Interaction of bismuth subnitrate with bentonite.

Deflocculated suspensions of coarse powders tend to cake as the individual particles settle out and form compact, cohesive sediments. Limited flocculation results in looser sediments because the settled-out flocs incorporate large amounts of the liquid suspending medium. Controlled flocculation of bismuth subnitrate suspensions was achieved by the addition of small amounts of bentonite. The interaction of the coarse, positively charge bismuth subnitrate particles in aqueous suspension with negatively charged, colloidally dispersed bentonite was investigated by measuring electrophoretic mobility, sedimentation volume, and viscosity. Gradual addition of bentonite dispersion to bismuth subnitrate suspensions first reduced the zeta-potential of the bismuth subnitrate particles from +28 mv to zero, then inverted it, and finally caused it to level off at -20 mv for bismuth subnitrate-bentonite weight ratios below 200. Owing to the much greater specific surface area of bentonite, the surface of the bismuth subnitrate lath-shaped crystals was completely covered by 0.5% of its weight in clay platelets. Adhesion was promoted by electrovalences between surface bismuthyl ions and cation-exchange sites of the clay and by secondary valences. The charge neutralization of bismuth subnitrate by bentonite was a heterocoagulation process: the addition of small amounts of the clay flocculated the bismuth subnitrate suspensions and eliminated caking. While the zeta-potential of the bismuth subnitrate particles leveled off when their surface was saturated with bentonite platelets, sedimentation volume and viscosity continued to increase when the clay concentration was increased further while maintaining the bismuth subnitrate concentration constant. The excess, nonadsorbed bentonite formed the characteristic house-of-cards structure, incorporating the bentonite-coated bismuth subnitrate particles as cornerstones.     

Genotoxic potential of respirable bentonite particles with different quartz contents and chemical modifications in human lung fibroblasts

Crystalline silica has been classified as a human carcinogen, but there is still considerable controversy regarding its fibrogenic and carcinogenic potential. In the present study, we investigated the genotoxic potential of bentonite particles (diameter < 10 microm) with an a-quartz content of up to 6% and different chemical modifications (alkaline, acidic, organic). Human lung fibroblasts (IMR90) were incubated for 36 h, 48 h, or 72 h with bentonite particles in concentrations ranging from 1 to 15 microg/cm2. Genotoxicity was assessed using the micronucleus (MN) assay and kinetochore analysis. The generation of reactive oxygen species (ROS) caused by bentonite particles via Fenton-like mechanisms was measured acellularly using electron spin resonance (ESR) technique and intracellularly by applying an iron chelator. Our results show that bentonite-induced genotoxic effects in human lung fibroblasts are weak. The formation of micronuclei was only slightly increased after exposure of IMR90 cells to an acidic sample of bentonite dust with a quartz content of 4-5% for 36 h (15 microg/cm2), 48 h (5 microg/cm2), and 72 h (1 microg/cm2), to an alkaline sample with a quartz content of 5% for 48 h and 72 h (15 microg/cm2), and to an acidic bentonite sample with 1% quartz for 72 h (1 microg/cm2). Native (untreated) and organic activated bentonite particles did not show genotoxic effects in most of the experiments. Also, bentonite particles with a quartz content < 1% were negative in the micronucleus assay. Generation of ROS measured by ESR was dependent on the content of transition metals in the sample but not on the quartz content or the chemical modification. Reduction of MN after addition of the iron chelator 2,2'-dipyridyl showed that ROS formation also occurs intracellularly. Altogether, we conclude that the genotoxic potential of bentonite particles is generally low but can be altered by the content of quartz and available transition metals.     

Genotoxic Potential of Respirable Bentonite Particles with Different Quartz Contents and Chemical Modifications in Human Lung Fibroblasts

Crystalline silica has been classified as a human carcinogen, but there is still considerable controversy regarding its fibrogenic and carcinogenic potential. In the present study, we investigated the genotoxic potential of bentonite particles (diameter < 10 μm) with an α-quartz content of up to 6% and different chemical modifications (alkaline, acidic, organic). Human lung fibroblasts (IMR90) were incubated for 36 h, 48 h, or 72 h with bentonite particles in concentrations ranging from 1 to 15 μg/cm². Genotoxicity was assessed using the micronucleus (MN) assay and kinetochore analysis. The generation of reactive oxygen species (ROS) caused by bentonite particles via Fenton-like mechanisms was measured acellularly using electron spin resonance (ESR) technique and intracellularly by applying an iron chelator. Our results show that bentonite-induced genotoxic effects in human lung fibroblasts are weak. The formation of micronuclei was only slightly increased after exposure of IMR90 cells to an acidic sample of bentonite dust with a quartz content of 4–5% for 36 h (15 μg/cm²), 48 h (5 μg/cm²), and 72 h (1 μg/cm²), to an alkaline sample with a quartz content of 5% for 48 h and 72 h (15 μg/cm²), and to an acidic bentonite sample with 1% quartz for 72 h (1 μg/cm²). Native (untreated) and organic activated bentonite particles did not show genotoxic effects in most of the experiments. Also, bentonite particles with a quartz content < 1% were negative in the micronucleus assay. Generation of ROS measured by ESR was dependent on the content of transition metals in the sample but not on the quartz content or the chemical modification. Reduction of MN after addition of the iron chelator 2,2′-dipyridyl showed that ROS formation also occurs intracellularly. Altogether, we conclude that the genotoxic potential of bentonite particles is generally low but can be altered by the content of quartz and available transition metals.     

Removal of dichloroacetic acid from drinking water by using adsorptive ozonation

Chloroacetic acids, formed during the disinfection process in potable water production, are considered to pose a potential risk to human health. This article deals with dichloroacetic acid (DCAA) removal from drinking water by using a process of bentonite based adsorptive ozonation. This process is formed by combined addition of ozone, bentonite and Fe³⁺. During the reaction, DCAA is removed by the joint effect of adsorption, ozonation and catalytic oxidation. In addition, under the effect of the adsorption, natural organic matters (NOM) can be adsorbed onto the bentonite surface, resulting in a reduced scavenging effect toward HO· radicals, and hence eliminate the negative effect of NOM on DCAA removal. At the initial stage of the reaction, Fe³⁺ is rapidly hydrolyzed to polycations and adsorbed onto the bentonite surface or into its structural layers. This positively charges the surface of the bentonite and increases its surface area, resulting in a strong adsorption of HA or DCAA. Furthermore, Fe³⁺ catalyzes ozone decomposition to form HO· thus further improving the efficiency. The adsorptive ozonation has been shown to be potentially advantageous in destruction of toxic, dissolved pollutants in drinking water, and appears to have great potential for a wide range of treatment applications.     

An in vitro model using the IPEC-J2 cell line for efficacy and drug interaction testing of mycotoxin detoxifying agents

An in vitro model simulating the intestinal barrier for efficacy and drug interaction testing of mycotoxin detoxifying agents was developed using Transwell® cell culture inserts. Intestinal porcine epithelial cells derived from the jejunum of piglets were exposed to DON and a mycotoxin binder (efficacy testing) or exposed to tylosin and a mycotoxin binder (drug interaction testing). Active carbon and bentonite were used in the efficacy and drug interaction trials, respectively, to validate the developed model. The evaluated parameters were passage of DON and tylosin through the epithelial monolayer, the integrity of the monolayer by measurements of the trans-epithelial electrical resistance and the viability of the monolayer using the neutral red assay. In the efficacy model it was shown that active carbon effectively bound DON at both non-cytotoxic and cytotoxic concentrations of DON, respectively 0.5 and 1 μg/mL. Moreover, the negative effects of DON at cytotoxic concentrations on cellular viability and integrity were completely offset. A commercially available modified gluco-mannan binder was also tested and it was able to partly reduce the negative effects on these latter parameter. Moreover, it reduced the transepithelial passage of DON with 37% to 57% compared to active carbon, at both cytotoxic and non-cytotoxic concentrations of DON. In our drug interaction model, the interaction between tylosin and mycotoxin binders was investigated as some authors suggest binding of macrolide antibiotics to bentonite clays. Indeed, a bentonite clay showed decreased passage of tylosin through the epithelial monolayer, indicating binding of tylosin by bentonite. This indicates that the combined use of bentonite and tylosin in the feed could lead to therapy failure. The modified gluco-mannan binder did not alter the passage of tylosin significantly, indicating safe combined use.