脱水穿心莲内酯琥珀酸半酯的稳定性研究

目的:研究脱水穿心莲内酯琥珀酸半酯(DAS)的稳定性,确定贮存条件。方法:以 HPLC 法测定 DAS 的含量。色普柱:Phenomenex C_(18)(250 mm×4.6 mm,5μm),流动相:甲醇-1.5%醋酸溶液(60:40),流速:1.0 mL·min~(-1),检测波长:251 nm。分别考察了光照、氧化、pH 及温度对 DAS 稳定性的影响,并用初均速法研究了 DAS 的热稳定性。结果:DAS 对光照、氧化稳定,对高 pH 不稳定,对温度不稳定。结论:DAS 宜在低温下保存。     

葡萄糖酸依诺沙星溶液的稳定性研究

目的考察葡萄糖酸依诺沙星溶液的稳定性。方法采用紫外分光光度法测定溶液中葡萄糖酸依诺沙星含量,HPLC法测定有关物质含量,考察了不同pH值的葡萄糖酸依诺沙星溶液在光照及高温条件下的质量变化。结果葡萄糖酸依诺沙星溶液在光照下易变色pH值5.5～6.0溶液在高温、光照5d后即出现结晶。pH值3.0～4.0溶液在光照条件下含量下降较多,有关物质增加较多。pH在4.0～5.5之间的葡萄糖酸依诺沙星溶液稳定性较好。结论本品应遮光保存,液体制剂的pH值范围确定在4.0～5.5之间较好。     

亚硫酸氢钠穿心莲内酯有关物质测定的方法学研究

目的:建立高效液相色谱法,测定亚硫酸氢钠穿心莲内酯的有关物质.方法:采用Diamonsil C18色谱柱(250 mm×4.6 mm,5 μm),甲醇-乙腈-0.02 mol·L-1磷酸二氢钾溶液(5:24:75)为流动相,220 nm为检测波长.结果:亚硫酸氢钠穿心莲内酯有关物质与主峰分离度大于1.5,最小检出量为4.0 ng.结论:本方法专属性好,简便快捷,可用于亚硫酸氢钠穿心莲内酯的质量控制.     

穿心莲内酯的溶解度和稳定性实验研究

目的考察穿心莲内酯在HBSS缓冲液中的溶解度和稳定性,为含穿心莲内酯制剂开发及生物利用研究提供有效的参考。方法将穿心莲内酯对照品分别溶解于不同pH值的HBSS缓冲液中,用反相高效液相色谱法测定穿心莲内酯的含量。结果穿心莲内酯在浓度4～128μmol/L范围内呈良好的线性关系;在酸性条件下基本稳定,在强碱性条件下(pH>10)会发生降解。结论穿心莲内酯能溶解并稳定于HBSS缓冲液中,该结果为穿心莲内酯实验研究和制剂研究提供了参考。     

HPLC同时测定穿心莲药材及其注射液中3种内酯类成分的含量

目的利用HPLC同时测定穿心莲药材及其注射液中穿心莲内酯、脱水穿心莲内酯和新穿心莲内酯的含量。方法色谱柱为Shimadzu Shim-pack VP-ODS柱(4.6 mm×150 mm,5μm),以甲醇-水(53∶47)洗脱,流速:1 mL.min?1,柱温:25℃,检测波长225 nm处检测穿心莲内酯,检测波长205 nm处检测脱水穿心莲内酯与新穿心莲内酯。结果穿心莲药材及其注射液中3种内酯类成分能达到很好分离,线性关系良好(r≥0.999 5);平均加样回收率为99.6%~101.2%,RSD<3%。结论本方法灵敏、准确、可靠、重复性好,可用于穿心莲药材及其注射液的质量评价与3种内酯类成分的快速测定。     

司帕沙星滴眼液的制备及稳定性考察

目的考察司帕沙星滴眼液的稳定性,确定其有效期.方法通过光照、高温、低温等影响因素试验,特定条件（40,50,60℃）下恒温15周加速试验及室温留样观察,测定其色泽、pH、含量、有关物质变化.采用高效液相色谱法测定含量及有关物质.结果采用恒温（恒湿）条件下15周内制剂的稳定性与室温留样观察结果一致.结论该制剂处方合理、质量稳定,有效期可达2年以上.     

注射用尼莫地平的处方制备及稳定性考察

目的:研制注射用尼莫地平,并进行稳定性考察。方法:采用正交试验法筛选最佳处方,加入乙醇、聚山梨醇80为助溶剂和甘露醇为支架剂制成粉针剂;注射用尼莫地平在强光(4 500±500)Lx,RH75%、RH92.5%,高温(60℃)条件下放置10d,考察样品的性状、pH值、溶液的澄清度及颜色、水分、有关物质、含量。结果:样品稳定性考察除光照条件不稳定外,其他条件下的各项指标均无明显变化。结论:本制剂制备工艺简单,稳定性较好。     

阿魏酸钠注射液的稳定性研究

目的：考察不同pH值及强光、高温等因素对阿魏酸钠注射液稳定性的影响，并对阿魏酸钠注射液进行加速试验考察。方法：将不同pH值的阿魏酸钠注射液在100％：恒温中静置30分钟，观察其降解率随时间变化情况；分别在4500b强光照射及．40℃、60℃高温条件下放置10天，观察阿魏酸钠注射液的各项指标变化情况；在30℃加速试验条件下放置3个月，考察阿魏酸钠注射液的稳定性。结果：药液pH值升高，阿魏酸钠的降解速度加快；强光及高温条件下放置10天，阿魏酸钠注射液的pH值、含量及有关物质均有不同程度的改变；30℃加速试验3个月，其pH值略有上升，含量有较明显改变。结论：阿魏酸钠注射液的稳定性受，pH值影响，且在光照及高温下不稳定。本品应避免光照及高温受热，宜低温贮存。     

胞磷胆碱钠注射液中有关物质研究

目的：对胞磷胆碱钠注射液中的有关物质进行分析,考察最大杂质的影响因素.方法：采用XtimateTM C18（250 mm×215;4.6 mm,5 μm）柱,以磷酸盐缓冲液（[0.1 mol·L^-1的磷酸二氢钾溶液和四丁基铵溶液（取0.01 mol·L^-1四丁基氢氧化铵溶液用磷酸调节pH至4.5）等量混合]）-甲醇（95：5）为流动相;流速：1.0 ml·min^-1;柱温：30℃;检测波长：276 nm; 进样量：10 μl.结果：通过47批样品有关物质检查、破坏性试验、异常毒性试验及灭菌温度比较,建立样品的杂质谱,并找出最大杂质的影响因素.结论：该杂质在碱性条件和高温条件下会明显增加,在生产工艺中应控制pH和灭菌温度.     

固态穿心莲内酯的降解

穿心莲Andrographis paniculata(Burm.f.)Wall.ex Nees.主要活性成分是穿心莲内酯(1)及其衍生物脱氧穿心莲内酯(2)、新穿心莲内酯(3)和14脱氧-11,12-二脱氢穿心莲内酯(4)等三萜内酯。该植物地上部分干粉在干燥环境中贮存一年以上,其总内酯含量减少26％。作者研究了穿心莲内酯在高温条件下的稳定性和可能的主要降解途径。     

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.     

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.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.