联立方程组新解法测定氯霉素地塞米松滴眼液中两组分的含量

建立氯霉素地塞米松滴眼液中两组分的含量测定方法。采用联立方程组新解法直接测定氯霉素地塞米松滴眼液中氯霉素和地塞米松磷酸钠的含量。以水为空白,分别以278nm和242nm为测定波长。氯霉素和地塞米松磷酸钠的平均回收率及RSD分别为100.2％、0.72％;99.43％、1.26％。氯霉素地塞米松滴眼液中两组分的含量,可采用联立方程组新解法,不经分离直接测定其吸收值,方法简便、快速、重复性好,可推广应用。     

联立方程组新解法测定氯霉素地塞米松滴眼液中两组分的含量

建立氯霉素地塞米松滴眼液中两组分的含量测定方法。采用联立方程组新解法直接测定氯霉素地塞米松滴眼液中氯霉素和地塞米松磷酸钠的含量。以水为空白,分别以278nm和242nm为测定波长。氯霉素和地塞米松磷酸钠的平均回收率及RSD分别为100．2％、0．72％;99．43％、1,26％。氯霉素地塞米松滴眼液中两组分的含量,可采用联立方程组新解法,不经分离直接测定其吸收值,方法简便、快速、重复性好,可推广应用。     

联立方程新解法测定氯霉素滴眼液中氯霉素的含量

目的：测定氯霉素滴眼液中氯霉素的含量。方法：用新Vierordt法直接测定，以278nm为测定波长，256nm为参比波长，纯化水为空白。结果：氯霉素的平均回收率及RSD分别为99．5％和0．3％。结论：用新Vierordt法可直接测定氯霉素滴眼液的含量，操作简单，能消除尼泊金乙酯的干扰，结果满意。     

紫外分光光度法测定氯霉素滴眼液的含量

目的 建立测定氯霉素滴眼液含量的方法。方法 采用紫外分光光度法，以水为空白，检测波长279nm。结果 氯霉素在251～50μg／ml浓度范围内具有良好的线性关系。平均回收率99．4％，RSD是0．33％。与中国药典方法相比差异无显著性。结论 方法简便、快速、准确、线性范围较宽，可用于测定氯霉素滴眼液含量。     

一阶导数光谱法测定氯霉素滴眼液中氯霉素的含量

目的建立氯霉素滴眼液中氯霉素含量的测定方法。方法采用一阶导数分光光度法。样品不经分离处理直接测定氯霉素滴眼液中氯霉素的含量，检测波长为300am。结果线性范围为8-64mg／L，r=0．9998，平均回收率为99．9％，RSD为1．2％。结论该法可消除其他组分的干扰，简便易行，适合作为氯霉素滴眼液的质量控制。     

氯霉素滴眼液质量稳定性的考察

目的促进氯霉素滴眼液质量稳定性的提高,保证人民用药安全有效。方法对本辖区内经营的氯霉素滴眼液进行抽样测定并分别置254nm和365nm的紫外光灯及40℃的温度下放置一定时间进行测定研究,采用《中国药典》2005年版二部氯霉素滴眼液项下的含量测定、有关物质检查的方法测定。结果抽验的氯霉素滴眼液不合格率为95.83%,主要不合格项目为氯霉素二醇物,经紫外光灯照射、40℃放置一定时间后,氯霉素的含量下降,氯霉素二醇物含量增加,对硝基苯甲醛受紫外光的影响较大而温度对其影响较小。结论①氯霉素滴眼液的储存条件应由20℃以下的阴凉处存放更改为冰箱内保存;②氯霉素滴眼液的处方工艺值得研究和改进。     

一阶导数分光光度法测定氯霉素滴眼液的含量

目的：建立一阶导数分光光度法测定氯霉素滴眼液的含量。方法：一阶导数分光光度法，在256nm处测定氯霉素滴眼液的振幅值D。结果：线性范围为29．42－88．27μg／ml，r＝0．99998(n=5)；平均回收率为100．5％，RSD=1．1％(n=7)。辅料无影响，测定结果与药典方法一致。结论：该法操作简便、快速、准确，适合于医院中氯霉素滴眼液的含量测定。     

双波长等吸收点法测定氯霉素滴眼液含量

目的：建立一种医院常用制剂氯霉素滴眼液快速准确的含量测定,满足医院制剂快速分析的需要。方法：采用双波长等吸收点计算分光光度法,不经分离消除尼泊金乙酯的紫外吸收干扰,直接测定制剂中的氯霉素的含量。结果：采用本法测定氯霉素滴眼液,其回归方程为：ΔA277-235=0.0216c 0.002214,r=0.9999,平均回收率99．26％,RSD 0．73％;样品测定均在标示量范围内。结论：本文所建立的双波长等吸收点计算分光光度法可有效消除制剂中防腐剂尼泊金乙酯的干扰,快速,准确地测定氯霉素滴眼液的含量。     

系数倍率法测定氯地滴眼液中氯霉素及磷酸地塞米松的含量

目的:探讨氯地滴眼液中氯霉素和磷酸地塞米松的含量测定方法。方法:采用系数倍率法,于244和279nm波长处分别测定氯霉素和磷酸地霉米松的吸收度,求出K值。绘制氯霉素与磷酸地塞米松混合液的标准曲线,得出△A与浓度的关系方程。测定样品在244和279nm波长处的吸收度,代入△A与浓度的关系方程,即可求出样品中氯霉素和磷酸地塞米松的含量。结果:氯霉素和磷酸地塞米松的平均回收率为99.6％,RSD分别为0.31％和0.34％。结论:此方法用于氯地滴眼液的含量测定,可避免氯霉素和磷酸地塞米松的相互干扰,方法简单,结果准确。     

以玻璃酸钠为载体的氯霉素滴眼液配制方法的改进

目的改进氯霉素滴眼液的配制方法。方法以玻璃酸钠为载体,配制氯霉素滴眼液,对滴眼液进行质量检测（鉴别检查,含量测定、稳定性试验）及刺激性试验。结果该滴眼液质量符合相关规定（鉴别反应呈阳性,pH为6．0—7．0）,氯霉素平均加样回收率为99．49％（RSD=1．76％）,12个月内质量稳定,实验家兔未出现眼睛刺激症状。结论本配制方法合理可行,制剂安全,质量稳定、可控。     

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.     

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.     

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.     

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.