HPLC法测定注射用氟氯西林钠氨苄西林钠的含量及有关物质

目的 建立注射用氟氯西林钠氨苄西林钠含量的HPLC测定方法。方法 使用C18柱。以磷酸二氢钾（0．1mol／L）：十二烷基硫酸钠（0．012mol／L）：甲醇：乙腈（280：300：200：220）（用磷酸调pH值至2．8）为流动相，检测波长为225nm。结果 氟氯西林钠与氨苄西林钠的线性范围均为0．03～0．60mg／ml。r均为0．9999。氟氯西林平均加样回收率为99．9％，RSD为0．6％（n=9）；氨苄西林钠平均加样回收率为99．9％，RSD为1．2％（n=9）。结论 该方法简便、准确、灵敏度高。同时对产品中的有关物质能进行准确控制。     

高效液相色谱法测定阿莫西林/氟氯西林钠胶囊溶出度

目的:建立阿莫西林/氟氯西林钠胶囊溶出度测定方法.方法:采用转篮法,以水为溶剂,转速为100r/min.高效液相色谱法,以C1s柱为色谱柱,以用磷酸调pH值至2.6的0.1 mol/L磷酸二氢钾-0.018 mol/L十二烷基硫酸钠-甲醇-乙腈(275:275:200:250)溶液为流动相,检测波长为225 nm.结果:阿莫西林与氟氯西林的线性范围均为0.03～0.60 mg/mL, r=0.999 9;平均加样回收率阿莫西林为99.8%,RSD=0.8%(n=9),氟氯西林为99.9%,RSD为1.3%(n=9).结论:高效液相色谱法简便、准确、灵敏度高.     

高效液相色谱法测定注射用阿莫西林钠氟氯西林钠有关物质和含量

目的：建立注射用阿莫西林钠氟氯西林钠有关物质和含量测定的高效液相色谱法。方法：用辛烷基键合硅胶为填充剂；以2％十六烷基三甲基溴化胺磷酸盐缓冲液-乙腈（68：32）为流动相；检测波长为225nm。结果：阿莫西林钠在28～227μg／ml浓度范围内、氟氯西林钠在31～245μg／ml浓度范围内均呈良好线性关系，回归方程分别为Y阿莫西林=139．59X＋819．73和Y氟氯西林=163．84X-4．3537，相关系数分别为r阿莫西林=0．9998，r氟氯西林=0．9999；平均回收率分别为100．2％和99．9％，RSD分别为1．07％和1．20％（n=9）。结论：本法可同时检测制剂中有关物质和两组分含量，简便、快速，结果准确。     

HPLC法同时测定复方阿莫西林氯唑西林钠胶囊的含量及有关物质

目的：建立同时测定阿莫西林氯唑西林钠胶囊的含量和有关物质的HPLC方法。方法：用C18（150mm×4．6mm,5μm）色谱柱,以乙腈：0．02mol·L^-1磷酸盐缓冲液（pH5．0）为流动相进行梯度洗脱,流速1．0ml·min^-1,检测波长230nm。结果：阿莫西林和氯唑西林均在0．10～0．60mg·ml^-1浓度范围内呈良好的线性关系。阿莫西林的平均回收率为99．4％,RSD=0．1％（n=9）。氯唑西林的平均回收率为99．4％,RSD=0．1％（n=9）。结论：方法可靠、简便、准确。可作为复方阿莫西林氯唑西林钠胶囊的含量和有关物质的质量控制。     

HPLC法同时测定注射用氨苄西林钠/氯唑西林钠的含量

用阳离子交换柱的HPLC法同时测定注射用氨苄西林钠／氯唑西林钠中氨苄西林和氯唑西林的含量。色谱条件：采用Hypersil SCX柱，磷酸盐缓冲液（0.01mol／L磷酸氢二铵溶液，用磷酸调节pH值6．0）：乙腈（90：10）为流动相，检测波长225nm。氨苄西林和氯唑西林分别在45-134和44～131μg／ml范围内呈良好的线性关系，日内RSD分别为0．5％和0．6％，回收率分别为99．9％和100．0％，含量测定结果与国家药品标准方法所得结果相符。     

复方氨苄西林-氟氯西林胶囊及有关物质的HPLC测定

建立了HPLC法测定复方氨苄西林．氟氯西林胶囊含量及有关物质。采用C18柱，流动相为缓冲溶液（含0．01mol／L溴化十六烷基三甲铵和0．01mol／L磷酸二氢钾，pH6．5）-乙腈（50：50），检测波长230nm。氨苄西林和氟氯西林的线性范围分别为0．06～1．67和0．06～1．5mg／ml。两者检测限分别为6和5ng。平均回收率分别为99．9％和99.8％。     

注射用阿莫西林钠/舒巴坦钠含量测定方法的研究

本文采用HPLC法测定注射用阿莫西林钠／舒巴坦钠的含量。固定相为ODS柱,流动相为NaH2P04(0．05mol／L)-甲醇(95：5),1mol／L磷酸调pH为3．6,检测波长为230nm。阿莫西林及舒巴坦的回归方程及线性范围分别为：Y=17548276．03X 106939．82 r=0．99991．4-4．8μg;Y=4664450．94X-11941．32 r=0．9994 0．3-2．7。平均回收率分别为100．0％,RSD=0．55％(n=6);99．6％,RSD=0．56％(n=6)。     

注射用氨苄西林钠／氯唑西林钠的含量测定

用阳离子交换柱的HPLC法同时测定注射用氨苄西林钠／氯唑西林钠中氨苄西林和氯唑西林的含量。色谱条件：采用Hypersil SCX柱,磷酸盐缓冲液（0．01mol／L磷酸氢二铵溶液,用磷酸调节pH值6．0）：乙腈（90：10）为流动相,检测波长225nm。氨苄西林和氯唑西林分别在45—134和44—131ug／ml范围内呈良好的线性关系,日内RSD分别为0．5％和0．6％,回收率分别为99．9％和100．0％,含量测定结果与国家药品标准方法所得结果相符。     

氟氯西林镁阿莫西林颗粒剂的HPLC法测定

建立了HPLC法测定氟氯西林镁阿莫西林颗粒剂的含量.采用C_18色谱柱,流动相A为0.02 mol/L磷酸二氢钾溶液(用2 mol/L氢氧化钠溶液调至pH 6.5,含1.5%溴化十六烷基三甲铵)-乙腈(60:40),流动相B为0.02 mol/L磷酸二氢钾溶液(用2 mol/L氢氧化钠溶液调至pH 6.5,含1.5%溴化十六烷基三甲铵)-乙睛(30:70),线性梯度洗脱;检测波长254 mn.氟氯西林和阿莫西林在250~2 500 Rg/ml浓度范围内线性关系良好,平均回收率为99.9%和100.4%,RSD为0.87%和0.77%.     

HPLC法测定阿莫西林双氯西林钠胶囊中阿莫西林和双氯西林的含量

目的:采用高效液相色谱法同时测定阿莫西林双氯西林钠胶囊中阿莫西林和双氯西林的含量。方法:采用 YWG C_(18)柱(4.6 mm×250 mm,5μm);流动相为0.01 mol·L~(-1)SDS 溶液(用磷酸调 pH 至4.2)-甲醇(60:40);柱温35℃,流速1.0 mL·min~(-1),紫外检测波长225nm。结果:阿莫西林在25～5000 ng 范围内线性关系良好,r=1.0000;双氯西林在12.5～2500 ng 范围内线性关系良好,r=0.9999。阿莫西林、双氯西林的平均回收率(n=6)分别为99.6%,99.4%;RSD 分别为1.8%,1.6%。结论:此法可作为控制阿莫西林双氯西林钠胶囊质量的方法。     

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.