高效液相色谱法测定呋塞米片的含量

目的建立测定呋塞米片含量的高效液相色谱(HPLC)法。方法色谱柱为CAPCELL PAK C18MGⅡ柱(1 250 mm×4.6 mm,5μm),以水-四氢呋喃-冰醋酸(60∶40∶0.8)为流动相,检测波长为272 nm,流速为1.0 mL/min。结果呋塞米平均回收率为99.38%,RSD为1.21%(n=6)。结论该方法操作简单,结果准确,可用于呋塞米片的质量控制。     

高效液相色谱法测定呋噻米注射液的含量

目的建立高效液相色谱法测定定呋噻米注射液含量的方法。方法C18(150mm×4.6mm,5μm)色谱柱,以水-甲醇-磷酸盐缓冲液(50∶49∶1)为流动相,流速1.0ml.min-1,检测波长为275nm。结果呋噻米在0.049~0.292μg范围内进样量与峰面积呈良好的线性关系(r=0.9999);平均回收率为98.94%,RSD为1.24%,n=9。结论本方法结果准确,重现性较好。     

HPLC法测定呋塞米注射液中的有关物质及含量

目的:建立高效液相色谱法测定呋塞米注射液中有关物质和含量。方法:使用月旭Ultimate C18(250 mm×4.6 mm,5μm)色谱柱;流动相为水-四氢呋喃-冰醋酸(70:30:1);流速:1.0 mL·min-1;检测波长为272 nm。结果:测得呋塞米的检测限为5 ng;在0.01～0.15 mg.mL-1的浓度范围内峰面积与浓度呈良好的线性关系,回归方程为:A=7.290C-6.594×104(r=0.9994),平均回收率为99.8%,RSD为0.4%。结论:本方法灵敏、准确、专属性强,可用于测定呋塞米注射液中的有关物质和含量。     

HPLC加校正因子的主成分自身对照法测定呋塞米片中有关物质的含量

目的:建立测定呋塞米片中杂质B(4-氯-5-氨磺酰邻氨苯甲酸)、最大单个杂质和总杂质的方法。方法:采用高效液相色谱(HPLC)-加校正因子的主成分自身对照法进行测定。色谱柱为Agilent ZORBAX SB-C₁₈(250 mm×4.6 mm, 5μm),以水-四氢呋喃-冰醋酸(70∶30∶1)为流动相,流速为1.0 mL·min^-1,检测波长为272 nm,进样体积为20μL,柱温为30℃。绘制呋塞米和杂质B的线性方程,以斜率计算杂质B相对于呋塞米的校正因子,用相对保留时间确定杂质B的位置,测定6家制药企业共15批呋塞米片中杂质B、最大单个杂质和总杂质的含量,并与杂质对照品外标法测得的结果进行比较。结果:杂质B的相对保留时间为0.31,检测质量浓度线性范围为0.041～12.19μg·mL^-1,校正因子为1.06,检测限为0.40 ng,定量限为0.81 ng。比较采用校正因子的主成分自身对照法和外标法测得的结果,差值为±0.01%,表明2种方法无显著性差异。结论:经方法学验证,本法简便快速,可准确测定呋塞米片中有关...     

HPLC法测定注射用呋塞米中有关物质的含量

目的:建立以高效液相色谱法测定注射用呋塞米中有关物质含量的方法。方法:色谱柱为Hypersil -ODS,流动相为水-四氢呋喃-冰醋酸(70∶30∶1) ,流速为1.0mL·min-1,检测波长为254nm,进样量为20μL,以自身对照法计算有关物质的含量。结果:呋塞米检测浓度的线性范围为50～2 000μg·mL-1(r=0.999 7) ,有关物质平均含量为0.78%。结论:本方法简便、快速、准确、重现性好,可用于该制剂的质量控制。     

辐照对呋塞米注射液含量的影响考察

目的:建立测定呋塞米注射液中呋塞米含量的方法,并考察呋塞米注射液吸收不同强度的γ射线辐照后含量的变化。方法:采用高效液相色谱法测定含量,色谱柱为Diamonsil Technology C18,流动相为甲醇-0.1%磷酸(60∶40),流速为1 mL.min-1,检测波长为286 nm。将同一批号的呋塞米注射液制备成20μg.mL-1溶液后放置于60Co-γ射线放射源中,一次性吸收1、2、4、8、16、25 kGy的辐照剂量后检测药物含量。结果:呋塞米检测浓度线性范围为6～24μg.mL-(1r=0.999 7);低、中、高浓度的平均回收率分别为100.15%、101.52%、101.35%;日间及日内RSD(n=3)均小于2%;当吸收辐照剂量在2 kGy以上时样品含量变化较大,2、4、8、16、25 kGy辐照后含量分别约为18、17、14、11、7μg.mL-1,辐照强度增加与含量下降呈线性关系(r=0.986 2)。结论:所建立的高效液相色谱法可用于呋塞米注射液的含量测定;辐照对呋塞米注射液的稳定性具有显著影响。     

高效液相色谱法测定头孢呋辛赖氨酸原料药的含量

目的:建立高效液相色谱法测定头孢呋辛赖氨酸原料药的含量。方法:采用Kromasil C8(250 mm×4.6 mm,5μm)色谱柱,流动相为pH 3.4,0.1 mol.L-1醋酸盐缓冲液-乙腈(85∶15),流速为1.0mL.min-1,柱温为35℃,检测波长为273 nm。结果:头孢呋辛在1.97～39.49μg.mL-1范围内,浓度与峰面积呈良好线性关系,相关系数r=0.999 8(n=7),平均回收率为99.6%(n=9,RSD=0.6%)。结论:本法操作简便,结果准确,可用于头孢呋辛赖氨酸原料药的含量测定。     

呋塞米膜剂的制备与质量控制

目的制备呋塞米膜剂并建立其质量控制方法。方法以聚乙烯醇、羧甲基纤维素钠等为辅料制备呋塞米膜剂。采用紫外分光光度法测定其主药呋塞米含量,测定波长为271 nm。结果呋塞米检测浓度在6.70~15.50μg.mL-1范围内线性关系良好(r=0.999 6),平均回收率99.98%(RSD=0.18%,n=5)。结论该膜剂制备工艺简单,含量测定快速、准确、质量可控。     

反相HPLC-内标法测定头孢呋辛酯的含量

建立反相HPLC(RP-HPLC法)-内标法测定头孢呋辛酯的高效液相色谱检测方法.用C18色谱柱(4,6mm×150mm,5μm),柱温:室温,流动相为0.2 mol/L磷酸二氢铵溶液-甲醇(62∶38),流速1.0ml/min,内标为奥硝唑,检测波长为278nm.结果头孢呋辛酯在50.0～300.0mg/L范围内线性关系良好(r=0.9999,n=3),平均回收率为98.95%,RSD为0.96%,精密度RSD为0.97%.该方法快速、准确、灵敏度高、专一性强,可用于头孢呋辛酯片的含量测定.内标法可以消除仪器和操作产生的误差,使结果更准确.     

高效液相色谱法测定他米巴罗汀胶囊的含量

目的建立他米巴罗汀胶囊含量测定方法。方法采用高效液相色谱法(HPLC)进行测定,色谱柱为CEC-C8柱(150 mm×4.6 mm,5μm),流动相为乙腈-0.1%磷酸-甲醇(1∶1∶1),检测波长为235 nm。结果他米巴罗汀在2.51~40.12μg/mL浓度范围内,峰面积与浓度呈良好的线性关系,r=0.999 9;重复性试验的RSD为0.12%(n=6),最低检测限为0.2 ng,平均回收率为99.60%,他米巴罗汀主峰与辅料有良好分离。结论此法简单、灵敏、专属性强、重现性好,结果准确可靠,适用于他米巴罗汀胶囊的质量控制。     

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.     

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.