醋酸布舍瑞林纳米粒的制备及体外释放特性研究

目的:制备醋酸布舍瑞林纳米粒并考察其体外释药特性。方法:以复乳法制备纳米粒。采用高效液相色谱法测定其含量并计算制剂包封率及载药量,透析袋法考察制剂体外释药特性。结果:所制制剂外观圆整,醋酸布舍瑞林检测浓度的线性范围为0.1～8.0μg·mL-(1r=0.999 9),平均回收率为105.38%,日内RSD<1.78%,日间RSD<0.93%。制剂包封率为(63.37±0.29)%,载药量为(1.03±0.09)%,在pH 7.4的磷酸盐缓冲液中72 h的累积释药百分率为62.35%。结论:该制剂制备工艺简单可行,具有明显的缓释效果。     

槲皮素包合物微球的制备及其体外释放研究

目的:制备槲皮素β-环糊精包合物-壳聚糖微球(QT-CD-CM),并考察其理化性质和药物体外释放性能。方法:采用有机溶剂挥发法制备槲皮素β-环糊精包合物,再用乳化分散-离子交联法、以三聚磷酸钠为交联剂制备壳聚糖微球,并考察其形态、粒径、包封率、载药量和体外释放情况。结果:制备的QT-CD-CM形态规则、均质、无粘连,平均粒径(3.327±0.124)μm,包封率为32.4%,载药量为12.3%,在5%乙醇-磷酸盐缓冲液介质中72h可以达到完全释药,释药过程符合一级动力学模型。结论:QT-CD-CM理化性质及体外释药性能良好,制备工艺简单,有望成为理想的槲皮素给药系统。     

甲硝唑结肠定位肠溶片的制备及质量控制

目的:研制甲硝唑结肠定位肠溶片的制备工艺和处方,考察其体外释放度并制定该剂型的质量评价标准.方法:模拟服药后该剂型在胃肠道中的生理释药过程,用3种不同pH值的磷酸盐缓冲液作为释放介质,分别在其最大吸收波长277,321和317nm处检测甲硝唑的吸收度,并根据特定时间的药物吸收计算出累计释放度.结果:药片在人工胃液、pH 6.8人工肠液不释药;在pH 7.8人工结肠液中2～20μg穖L-1范围内线性良好,平均回收率104.8%,RSD为0.98%.结论:甲硝唑结肠定位肠溶片的体外释放度检测结果合格.     

高电压静电成囊技术制备牛血清白蛋白微囊的探索

采用高电压静电成囊装置,以牛血清白蛋白(BSA)为模型药物,制备牛血清白蛋白-海藻酸钙-壳聚糖微囊,考察微囊载药情况及在pH7.4磷酸盐缓冲液中的释放行为.本法制得的微囊球形圆整,平均粒径为(38.1±15.6)um,在生理盐水中溶胀率为119%.增大投药量、壳聚糖浓度或升高CaCl2溶液pH,有利于增大微囊的载药量.BSA/海藻酸钠比例为0.5和1.0时,30min累积释放率分别为42.84%和16.30%.     

去甲斑蝥素肝动脉栓塞缓释微球的制备及其体外释放性评价

目的:制备去甲斑蝥素肝动脉栓塞缓释微球(NCTD-MS),并考察其体外释放特性。方法:以NCTD为主药,海藻酸钠ALG)/壳聚糖(CS)为复合载体,采用内部凝胶化法制备NCTD-MS;选取ALG浓度、凝胶化反应剂冰醋酸的用量、药物-载体重量比(简称药载比)为因素,以粒径偏差、载药量及包封率为指标进行正交设计优化最佳处方并进行验证;动态透析法考察微球在不同介质(磷酸盐缓冲液和生理盐水)中的体外释放特性,并与NCTD原料药的释放性进行比较。结果:最佳处方为ALG浓度2.0%、冰醋酸1.0mL、药-载重量比0.8∶1,以该处方制备的微球平均粒径为(309.75±2.19)μm、载药量为(12.65±0.87)%、包封率为(68.66±0.38)%;NCTD-MS在2种介质中24h释放可达80%,释放行为均遵循Weibull方程,而NCTD原料药在3h内即释放完毕。结论:NCTD-MS制备工艺简单,缓释效果明显。     

齐墩果酸/PLGA-TPGS纳米粒的制备及其体外释放行为研究

目的:制备齐墩果酸/乳酸羟基乙酸共聚物-水溶性维生素E衍生物(PLGA-TPGS)纳米粒(OPN)并考察其体外释放情况。方法:用自制的PLGA-TPGS为载体材料,采用超声乳化-溶剂挥发法制备OPN,考察其粒径、Zeta电位、载药量、包封率、体外累积释放率。结果:所制OPN的平均粒径为(202.4±1.2)nm,Zeta电位为(-21.5±2.2)mV,载药量为(27.65±2.27)%,包封率为(92.52±2.15)%,其在含1.0%十二烷基硫酸钠的磷酸盐缓冲液(pH7.4)中呈两相释放,432h时累积释放率为(93.8±2.9)%。结论:所制OPN质量稳定、可控,具有明显的体外缓释作用。     

萘普生微囊的制备及其质量考察

目的:制备萘普生微囊并考察其制剂质量。方法:以明胶和阿拉伯胶为囊材,采用复凝聚法将萘普生制成微囊;以阿拉伯胶浓度(A)、萘普生与阿拉伯胶的质量比例(B)和成囊温度(C)为考察因素,包封率为指标设计正交试验优化成囊的最佳制备工艺,并对优化工艺所制得微囊的粒径、包封率、载药量、体外释放性进行考察。结果:最佳工艺条件为A2%、B1:1、C50℃;所制微囊的平均囊径48.92μm,包封率(77.03±1.43)%,载药量(35.31±1.02)%,微囊在48h时体外累积溶出百分率达到91.32%。结论:所制萘普生微囊工艺重现性好、稳定,并具有良好的缓释作用。     

阿替洛尔缓释微囊载药量的测定及体外释放行为研究

目的 建立以乙基纤维素为囊材的阿替洛尔缓释微囊载药量测定方法,考察pH环境对微囊释药行为的影响.方法 采用HPLC法测定微囊的载药量,固定相为Grace Smart RPC18柱(250 mm×4.6 mm,5μm);流动相为甲醇-pH 3.0磷酸盐缓冲液(30∶70);流速为1 mL· min-1;检测波长为226 nm;柱温为25℃.分别以水、0.1 mol·L-1盐酸溶液、pH6.8的磷酸盐缓冲液为释放介质,采用桨法测定微囊累积释放度,应用SPSS 13.0软件对3种介质下含药微囊的释放行为进行单因素方差分析.结果 辅料对载药量的测定无影响,线性范围为8～64 μg·mL-1,r=0.999 8,平均回收率为100.2％,各项精密度符合要求.pH的变化对药物释放无影响.结论 建立的载药量测定方法良好,可用于载药量的测定.     

阿奇霉素微囊的制备与质量控制

目的:制备阿奇霉素微囊,并建立其质量控制方法。方法:以明胶为囊材,阿奇霉素为主药制备微囊。采用紫外分光光度法于482nm波长处测定阿奇霉素的含量,同时考察微囊的形态、粒径、载药量、包封率等指标。结果:所制微囊呈圆形,粒径均匀,平均体积径为100.96μm,平均载药量为23.8%,平均包封率为(68.72±0.89)%。阿奇霉素检测浓度的线性范围为7.5～52.5mg·L-1,平均回收率为(99.5±1.02)%,RSD=1.03%。结论:该制剂制备工艺可行,含量测定方法简便、可靠。     

甲硝唑微囊的制备及质量评价

目的制备甲硝唑微囊并对其质量进行评价。方法以明胶和阿拉伯胶为囊材,采用复凝聚法制备甲硝唑微囊,并对微囊的包封率、载药量和体外释药性进行考察。结果所制微囊包封率在72%以上,载药量大于40%,8h时累积释药量达85%。结论该制剂制备方法简便易行,质量评价合格。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.