手性介孔二氧化硅载体对地西泮溶出行为的改善

目的建立接枝L-酒石酸的手性介孔二氧化硅的药物释放系统,提升地西泮的体外溶出度,考察手性介孔硅对地西泮的体外释放特点。方法将L-酒石酸接枝硅烷偶联剂制备手性共结构导向剂,以共缩聚法制备手性介孔硅载体。将疏水性药物地西泮载入载体孔道构建药物释放系统,利用不同pH值的释放介质中的体外溶出测试评估载体对药物释放的调控能力。结果载体内部的介观孔道促使药物晶体发生无定型化转变,药物体外释放的速度和程度较原料药均得到显著提升,30 min内释放量提升4.6～6.4倍,24 h内释放量提升1.39～1.78倍,药物从载体中的释放速度随着载体比例的增加而变快。结论手性介孔硅具有良好的药物装载结合和控制释放能力,可以有效提高地西泮的体外溶出,将进一步提高药物的生物利用度,有利于其临床应用。     

对乙酰氨基酚/MCM-41载药体系的制备及其缓释性能的研究

目的制备对乙酰氨基酚/MCM-41缓释体系,并考察其体外释放行为。方法在碱性和室温条件下制备MCM-41介孔材料;采用浸渍法将解热镇痛药物对乙酰氨基酚组装到MCM-41的孔道中,通过XRD、IR、低温N2吸附对MCM-41介孔材料及药物组装体进行表征;测定组装体的载药量、载药时间以及在人工胃液中的释放行为。结果介孔材料MCM-41作为药物载体具有较短的载药时间(7 h)、较大的载药量(46.65%)、较低的释放速率(6 h仅释放35.6%)。结论通过测定组装体在体外模拟人工胃液和人工肠液中的释放速率,结果表明制得了对乙酰氨基酚/MCM-41缓释释放体系。     

两种介孔二氧化硅载体用于改善西洛他唑溶出度的比较

目的研究两种介孔二氧化硅(MCM-48和MCM-41)作为西洛他唑(cilostazol,CLT)的载体在改善药物溶出度方面的作用。方法分别采用3种方法制备CLT/MCM-48和CLT/MCM-41固体分散体,以紫外分光光度法测定样品的载药量。以溶出度为评价指标,对载药方法、药物与载体的质量比和固体分散体粒径等因素进行了优化,并应用氮气吸附和低温DSC法分析样品中药物的存在状态。结果当药物与载体质量比为1∶3时,以共沉淀法制备的CLT/MCM-48和CLT/MCM-41样品,经150μm孔径筛处理后,药物的溶出度最高,分别达到78%和85%。与以PEG4000为载体制备的CLT/PEG相比,显示了更加优良的药物溶出的稳定性。氮气吸附结果表明药物已经成功分散于载体孔道中;DSC分析显示,药物极有可能以无定形存在,且介孔孔道对药物向稳定型转变有延缓和阻滞作用。结论 MCM-48和MCM-41作为药物载体制备固体分散体能够不同程度地提高CLT的溶出度。     

介孔分子筛MCM-41对阿司匹林缓释作用的研究

目的研究介孔分子筛MCM-41对阿司匹林的缓释作用。方法以正硅酸乙酯为硅源,CTAB为模板剂,于室温、酸性条件下合成介孔分子筛MCM-41。采用浸渍法将阿司匹林装载在MCM-41孔道中,考察分子筛对阿司匹林的最大载药量。利用XRD、氮吸附、红外光谱法对组装前后的分子筛进行表征,并研究组装于分子筛上的阿司匹林在磷酸盐缓冲溶液中的释放情况。结果 MCM-41对阿司匹林的最大载药量达0.34 g.g 1。组装体中的阿司匹林8 h和31 h时累积释放67.6%和90.2%。结论介孔分子筛MCM-41对阿司匹林具有明显的缓释作用,介孔分子筛可作为一种新型药物缓释材料。     

扎鲁司特介孔二氧化硅固体分散体的制备及其体外释放考察

目的 制备扎鲁司特（zafirlukast,ZLST）介孔二氧化硅固体分散体,提高体外溶出速度。方法 通过溶胶凝胶法制得介孔二氧化硅（MCM-41）,将其甲基化改性（MCM-41CH₃）;采用浸渍挥干法将ZLST载入,测定体外溶解速度;并采用X射线衍射、差示扫描量热、傅立叶变换红外光谱、扫描电镜、透射电镜等手段对固体分散体进行表征。结果 药物介孔二氧化硅固体分散体可以显著地加快药物的溶出速度,ZLST-MCM-41的释放率略高于ZLST-MCM-41CH₃;物相鉴定表明,ZLST以无定型或微晶形式分散于介孔载体中。结论 介孔二氧化硅可以作为ZLST优良的载体材料。     

介孔分子筛作为药物载体应用于缓/控释及靶向制剂的研究进展

目的:为介孔分子筛作为药物载体应用于缓/控释及靶向制剂提供参考。方法:"介孔分子筛""药物载体""缓释""控释""靶向""Mesoporous molecular sieves""Drug carrier""Sustained release""Controlled release""Targeting"等为关键词,组合查询1985年1月-2017年6月在中国知网、万方、维普、Pub Med、Web of Science等数据库中的相关文献,就介孔分子筛的分类及特点、对药物体外释放行为的影响、药物体外释放动力学机制、药物体内药物动力学及生物活性等研究进行综述。结果与结论:共检索到相关文献31 052篇,其中有效文献38篇。根据介观结构分类,介孔分子筛主要有2D结构的MCM-41,3D结构的MCM-48及无序、层状结构的HMS、MSU、TUD-1。MCM-41的相关研究较MCM-48、MSU及TUD-1多;HMS及介孔二氧化硅纳米粒子载药量大且可修饰性好;介孔分子筛的孔径尺寸、修饰分子、有序度和载药方法及模型药物固有特性等因素,均对药物体外释放行为产生影响;MCM-41及MCM-48的生物活性较好且COK-12以人为受试对象进行药动学评估时未见明显排斥反应。现有研究主要从结构修饰、嫁接、改变载药模式等方面进行缓/控释及靶向传递的研究。今后应着眼于提高模型药物多样性研究,评价介孔分子筛的体内毒性及生物相容性,构建修饰与掺杂型载体,以设计出适宜用于人体的多功能、多靶向、多重刺激响应、高载药量、低毒性的新型药物传递系统。     

格列齐特推拉式渗透泵的制备

目的:优化格列齐特推拉式渗透泵的处方,并对影响释放度的各种因素进行考察。方法:以紫外分光光度法对格列齐特推拉式渗透泵的体外释放度曲线进行测定,应用f2因子法为手段,对不同处方中药物释放曲线的相似性进行评价,对处方进行优化。结果:包衣增重、片心硬度及助推层中氯化钠的用量对药物的释放曲线有显著影响,释药孔径大小、转速以及打片时的填料顺序对释放曲线无显著性影响。结论:应用推拉式渗透泵系成功制备了格列齐特渗透泵,控释时间达12 h。     

反卷积分法研究长春西汀推拉式渗透泵控释片体内外相关性

目的：采用反卷积分法评价长春西汀渗透泵控释片的体外释放与Beagle犬体内吸收相关性。方法：以0．5％SDS水溶液为溶出介质，测定长春西汀的体外释放度；高效液相色谱测定犬体内血药浓度，选择长春西汀普通片为参比制剂，应用反卷积分法评价长春西汀推拉式渗透泵体内体外相关性。结果：体外累计释放度（Y）与输入函数（R）回归方程为iY=237．99R-13．544（r=0．9763），表明长春西汀推拉式渗透泵体内体外相关性良好。结论：反卷积分法适合自制长春西汀推拉式渗透泵控释片体内外相关性研究。     

厄贝沙坦胃滞留夹芯渗透泵片的制备及体外释放度考察

目的对厄贝沙坦胃滞留夹芯渗透泵片(SOPT)的制备方法进行研究,并考察其体外释放度。方法分别以膨胀速度、水渗透速率、低剪切黏度、屈服应力及释放度为评价指标,确定处方中膨胀剂材料、致孔剂、助悬剂、促渗剂的用量。结果最佳处方:膨胀剂为PEO(Mw 5 000 000)与HPMC混合物(4∶1),用量70 mg;促渗剂氯化钠用量为25 mg;包衣液致孔剂PEG400用量8%;助悬剂PEO(Mw 200 000),用量为厄贝沙坦的1/4。释药行为符合零级方程,具有明显的控释特征。结论 SOPT具有良好的体外控释效果,可进一步进行体内释药行为考察。     

尼莫地平双层渗透泵片的制备及其体外释放度考察

目的:制备尼莫地平双层渗透泵控释片,并考察其体外释放度。方法:以体外累积释放度作为评价指标,以含药层助悬剂聚氧化乙烯(PEO)200000的用量、促渗剂氯化钠的用量、致孔剂聚乙二醇(PEG)2000的含量及包衣增重为考察因素,采用正交设计优化尼莫地平双层渗透泵控释片的处方;参照《中国药典》释放度测定法第二法测定其体外释放度。结果:最优处方为含药层PEO20000080mg,氯化钠10mg,助推层PEO500000040mg,PEG2000用量8%,包衣增重8%。所制片剂释药速率恒定,12h的体外累积释放度达90%以上。结论:尼莫地平双层渗透泵片工艺稳定,体外释放行为在12h内具有明显的零级释放特征(r=0.9903),达到了控释要求。     

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.