抗癌药达沙替尼的热稳定性与晶型研究

本文对药物达沙替尼的热稳定性和晶型进行分析与研究。通过差示扫描量热仪(DSC)和热重分析仪(TGA)分析达沙替尼的热稳定性;通过X射线粉末衍射仪(XRD)及其原位高温附件(in situ high temperature)测定达沙替尼试样的多晶型结构及相转变。结果表明,达沙替尼存在两种晶型(分子中分别含1个结晶水和1.5个结晶水),在加热过程中两种晶型都会发生结构变化,失去结晶水后,最终变为相同的晶体结构,其熔点分别为285.68℃和285.50℃。     

盐酸小檗碱的热特征分析

目的:观察盐酸小檗碱的热特征,并测定其水分。方法:利用热分析技术中的差示扫描量热法(DSC)和热重分析法(TGA)对盐酸小檗碱进行热特征分析并测定其游离水和结晶水含量。结果:国内不同生产企业生产的盐酸小檗碱热特征图谱不同,结晶水含量均为7%左右。结论:热分析用于药物晶型研究以及熔点、结晶水含量等的测量,具有用量少、快速、灵敏高、检测方便等优点。     

黄体酮的热特性分析

目的:观察黄体酮药物的热特性,并测定其纯度。方法:利用差示扫描量热法(DSC)和导数热重法(DTG)测定黄体酮的熔点、纯度及挥发性物质,在氮气氛下升温速率分别为1.5,10,20℃·min~(-1)。结果:用差示扫描量热法,升温速率为1.5℃·min~(-1),测定黄体酮的熔点为130℃,在程序控温下对其吸热峰进行分析,其纯度为99.8%,与高效液相色谱测定的结果(99.9%)一致。用导数热重法可准确测定其挥发性物质包括水分在内的变化,以及推测其降解历程。结论:该分析法简便、快捷,可测定黄体酮的晶型、水分及纯度,并为研究降解机理及开发新剂型提供参考。     

氨基葡萄糖盐酸盐晶型的初步研究

目的研究氨基葡萄糖盐酸盐的多晶型现象。方法采用熔点测定、粉末X射线衍射(XRD)、单晶X射线衍射、差示扫描量热分析(DSC)、热重分析(TGA)等技术对样品晶型进行测定分析。结果各晶体熔点、XRD、DSC等数据均表现明显差异性。结论氨基葡萄糖盐酸盐存在多晶型现象。     

新型抗抑郁药A613晶型的定量测定

目的建立抗抑郁药A613晶型的定量测定方法,并考察其原料药晶型稳定性。方法采用差示扫描量热法,氮气气氛下,升温速率20 ℃•min－1,升温范围：40～120 ℃,参比物：铝坩埚,对抗抑郁药A613的不同晶型进行定量测定。结果测得熔点温度、熔化焓等热力学参数,样品用量在0.1～4.0 mg范围内质量与熔化焓呈线性,线性方程为Y＝－108.870 0X－4.275 8,r＝0.999 6。结论所建立的方法可为生产工艺研究和判断产品质量提供快速、有效的测试方法。     

注射用米铂的制备及表征

目的：制备和表征注射用米铂。方法：快速冷冻法制备注射用米铂；以热分析（DSC-TG）法测定药物的熔点及水分含量，采用动态光散射法考察药物的粒径分布，采用扫描电镜观察其微观形态。结果：注射用米铂在182.60℃发生微小的晶相转变，从亚稳态晶型转变为稳态晶型，219.41℃发生熔融变化，开始分解；粒度分布特征值（d0.1 5.353 μm，d0.5 9.601 μm，d0.9 17.332 μm）；扫描电镜观察其微观形态呈类球形。结论：成功制备注射用米铂微粒，便于工业化生产。     

关于三氮唑核苷结晶晶型的研究

据国外报道抗病毒药三氮唑核苷有二种晶型和熔点:高熔点174～176℃,低熔点166～168℃。国内制得的样品熔点166～178℃,熔距较长。为了探索三氮唑核苷的结晶条件、晶型与熔点的关系,将样品经不同溶剂重结晶即可得二种晶型和熔点,其高、低熔点与国外报道的高、低熔点基本相符。而且二种晶型再经不同溶剂重结晶,晶型可相互转换,熔点及红外光谱也可相应转换;但二种晶型的核磁共振谱则相同。通过各种测定和试验,证明三氮唑核苷虽有不同的晶型和熔点,但其组份是一致的,抗病毒作用效果也相同。     

(S)-N-环氧丙基邻苯二甲酰亚胺的单晶制备及其表征

目的制备(S)-N-环氧丙基邻苯二甲酰亚胺的单晶,并对其进行结构表征和均浆稳定性研究。方法通过溶剂挥发法和气相扩散法制备(S)-N-环氧丙基邻苯二甲酰亚胺晶型。利用差示扫描量热仪(DSC)、热重分析仪(TGA),红外光谱仪(IR),粉末X射线衍射仪(PXRD)和单晶X射线衍射仪(SXRD)分别对制备得到的晶体样品进行表征。结果制备得到的(S)-N-环氧丙基邻苯二甲酰亚胺晶体样品,其DSC、TGA、IR和PXRD图谱均一致,即晶型一致;DSC结合TGA分析结果显示,(S)-N-环氧丙基邻苯二甲酰亚胺熔点为100.56℃,分解温度为128.2℃。单晶X射线衍射结果表明该晶胞属于单斜晶系,P2_1空间群,结构偏离因子R=0.04,分子式为C_(11)H_9NO_3,相对分子质量为203.19,立体构型与预测构型一致。均浆稳定性实验结果表明,不同极性溶剂中得到的晶体粉末X射线未发生变化,即晶型稳定性良好。结论实验确证了(S)-N-环氧丙基邻苯二甲酰亚胺的立体结构,且晶型稳定性良好。     

盐酸阿替卡因的多晶型研究

目的:建立盐酸阿替卡因多晶型的测定方法并研究其理化性质.方法:研究了不同晶型的盐酸阿替卡因的制备方法,采用熔点测定、差示扫描量热法(DSC)、红外吸收光谱法(IR)及粉末X-衍射法(Powder X-ray)研究了不同晶型的特征,并考察了2种晶型在高湿、高温和光照条件下的稳定性.结果:盐酸阿替卡因存在2种不同的晶型,晶型Ⅰ和晶型Ⅱ.通过熔点测定、DSC和IR分析及粉末X-衍射法可区分2种晶型.晶型Ⅰ有较强的吸湿性,而晶型Ⅱ不易吸湿,2种晶型对光照和高温均较稳定.结论:盐酸阿替卡的晶型Ⅱ适合作为药物应用.     

热重和差示扫描量热分析技术在药物分析中的应用进展

目的 探讨热重分析（TGA）和差示扫描量热分析（DSC）在药物分析中的应用,为药品质量控制奠定基础。方法 通过文献综述着重报道了这2种技术方法在水分含量分析、热稳定性研究、熔点测量、纯度分析、晶型分析等药物研究中的多方面应用研究情况。结果与结论 热重和差示扫描量热分析技术在药物的水分、熔点、纯度、晶型以及稳定性等相关分析中发挥重要作用,满足药品检验检测工作的更高分析需求。     

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.