多索茶碱脉冲控释微丸的研制

目的 研究多索茶碱脉冲控释微丸的制备工艺,并考察其释药性能。方法 以微晶纤维素为骨架材料采用挤出滚圆法制备载药丸芯,通过流化床包衣法分别覆上交联羧甲基纤维素钠作为溶胀层、乙基纤维素和羟丙甲纤维素作为控释层制备多索茶碱脉冲微丸,通过单因素考察筛选丸芯、溶胀层、控释层的处方组成对体外释药性能的影响。结果 以微晶纤维素、羧甲基淀粉钠和乳糖为添加剂可制得性能良好的高载药微丸。随着溶胀层厚度的增加,药物释放时滞变短,速率显著增加;随着控释层包衣厚度的增加,时滞延长,释药减慢;控释层中羟丙甲纤维素用量或分子量增加,时滞缩短;控释层中增塑剂用量增加,时滞延长。结论 所得包衣微丸具有良好的脉冲释药性能,有广阔的应用前景。     

硫酸沙丁胺醇脉冲控释微丸的制备

为制备硫酸沙丁胺醇脉冲控释微丸，采用挤出滚圆法制备载药丸芯，使用水溶胀性材料为内包衣溶胀层，乙基纤维素水分散体为外包衣控释层制备脉冲控释微丸，并考察溶胀层材料类型、十二烷基硫酸钠(SDS)含量、溶胀层和控释层包衣增重对药物释放的影响。结果表明．药物通过控释层衣膜破裂而释放，溶胀层材料类型、内包衣层中SDS的加入与否、溶胀层和控释层厚度对脉冲控释微丸的释药时滞和释药速率均具有显性影响。结论：采用低取代羟丙基纤维素为溶胀性材料．并加入1．5％SDS，共同作为内包衣层．制备的脉冲控释微丸，当内包衣层和外包衣层增重均为18％时。在模拟人体内胃肠道pH值变化条件下达到了时滞为4．5h，时滞后1．5h累积释药80％以上的脉冲释药效果。     

5-氟尿嘧啶结肠定位释药微丸的研制及释药特性

采用流化床喷雾包衣法,研制了2种5-氟尿嘧啶结肠定位释药微丸.以羟丙甲纤维素为溶胀层,乙基纤维素水分散体为控制层,制备时间依赖型包衣微丸;另以肠溶型丙烯酸树脂Eudragit S100为包衣材料,制备pH依赖型微丸.测定了2种微丸在模拟胃肠道各区段pH环境下的释放度.结果表明,时间依赖型包衣微丸体外持续、缓慢释放;pH依赖型包衣微丸在模拟胃和小肠中上部pH的介质中基本不释药,在模拟回盲部区段pH介质中脉冲释药,即后者在体外显示出较好的结肠定位释药特性.     

5-氨基水杨酸时控结肠定位控释微丸及其制剂的研制

目的制备5-氨基水杨酸微丸及其时控结肠定位控释释药系统的研究。方法首先采用挤出滚圆机制备了含药微丸,然后使用流化床包衣设备将微丸包衣,以羟丙甲纤维素和微粉硅胶的混合物包衣作为溶胀控释层,以乙基纤维素水分散体Surelease包衣作为时滞包衣层,并将包衣微丸装入肠溶胶囊。用释放度测定法研究微丸的释放行为。结果药物通过时滞层破裂开始释放,该层厚度增加可显著延长释药时滞。调节羟丙甲纤维素的型号、包衣增重及羟丙甲纤维素与微粉硅胶两者比例,可以控制药物释放速度。在模拟胃肠道pH情况下延迟5 h释药,之后的10 h内释药完全。结论可通过调整溶胀控释层包衣混合物的比例、型号、包衣厚度及时滞层的包衣厚度,制备5-氨基水杨酸时控结肠定位控释释药系统。     

法莫替丁缓释微丸的悬浮包衣法制备

采用淀粉和蔗糖为赋形剂制备法莫替丁含药微丸，以乙基纤维素为包衣材料，采用悬浮包衣法制备了法莫替丁缓释微丸，并用正交设计筛选出了最佳制备工艺参数。释放度研究结果表明：在进风温度为45℃，喷雾压力为147kPa及输液速度为10ml/min的条件下进行包衣，可制得在12h内释药符合Higuchi模型动力学过程的缓释微丸。     

双氯芬酸钠乙基纤维素水性分散体包衣片影响药物释放因素的研究

目的：考察影响双氯芬酸钠乙基纤维素水性分散体包衣片体外释药的因素。方法 以乙基纤维素水性分散体为包衣材料,双氯芬酸钠为模型药物,考察增塑剂的用量,膜厚,后处理温度和时间对双氯芬到钠包衣片体外释药的影响。结果 增塑剂用量越大释药越慢,用量不足民膜不完全,经物释放快,有得过大,产生粘连现象,膜厚增加,药物释放慢,过厚则出现时滞现象。后处理温度增加,药物释放变慢中国药科后处理温度一般选择高于最小成膜温度     

阿莫西林脉冲释药微丸的研制

目的:制备阿莫西林脉冲释药微丸。方法:取空白丸芯分别以含药层、溶胀层(羧甲基淀粉钠)和控释层(乙基纤维素水分散体)顺序依次进行包衣制备阿莫西林脉冲释药微丸。采用紫外法和篮法考察溶胀层(12%、16%、20%)和控释层包衣增重(24%、28%、32%)及不同介质(水、盐酸、pH6.8磷酸盐缓冲液)对药物释放的影响。结果:溶胀层和控释层包衣增重对脉冲控释微丸的释药时滞和释放速率具有显著影响,药物释放情况不受介质pH值的影响;溶胀层和控释层包衣增重分别为16%、28%时制备的微丸时滞时间约为4h,时滞后4h累积释药率达到80%。结论:所制备的阿莫西林脉冲释药微丸具有体外脉冲释放作用。     

硫酸沙丁胺醇脉冲控释微丸的制备

目的制备硫酸沙丁胺醇脉冲控释微丸。方法采用挤出滚圆法制备载药丸芯 ,使用水溶胀性材料为内包衣溶胀层 ,乙基纤维素水分散体为外包衣控释层制备脉冲控释微丸 ,并考察溶胀层材料类型、十二烷基硫酸钠 (SDS)含量、溶胀层和控释层包衣增重量对药物释放的影响。结果药物通过控释层衣膜破裂而释放 ,溶胀层材料类型、内包衣层中SDS的加入与否、溶胀层和控释层厚度对脉冲控释微丸的释药时滞和释药速率均具有显著性影响。结论采用低取代羟丙基纤维素为溶胀性材料 ,并加入 0 0 5 2mol LSDS ,共同作为内包衣层 ,制备的脉冲控释微丸 ,当内包衣层和外包衣层增重均为 1 8%时 ,在模拟人体内胃肠道pH值变化条件下达到了时滞为 4 5h ,时滞后 1 5h累积释药 80 %以上的脉冲释药效果     

双氯芬酸钠缓释微丸胶囊的制备

目的：制备膜控释双氯芬酸钠缓释微丸胶囊;方法：以乙基纤维素为包衣材料,以PEG100为致孔剂,经薄膜包衣制备双氯芬酸钠缓释微丸胶囊,并以体外释放度试验来评价;结果：制备的双氯芬酸钠缓释微丸胶囊的体外释药行为符合零级方程,批与批之间的重现性良好;结论：采用该法制备的双氯芬酸钠缓释微丸胶囊缓释效果好,制备工艺稳定。     

盐酸可乐定脉冲释药微丸的制备工艺研究

目的研究盐酸可乐定脉冲释药微丸的制备方法。方法采用挤出-滚圆工艺和流化床包衣法制备,用正交试验设计优化处方,考察产品的体外释放度。结果各考察因素均对药物的释放影响显著。优选工艺结果为,含药丸芯采用微晶纤维素,溶胀层材料采用低取代羟丙纤维素,控释层采用乙基纤维素水分散体,溶胀层和控释层包衣增重分别为10％和15％。制备的微丸时滞时间为4．2h左右,时滞后1h内累积释药百分率达到90％。结论盐酸可乐定微丸在体外具有有脉冲释药特性。     

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.     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.     

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.