HPLC法测定复方磺胺甲噁唑颗粒剂的含量

目的:采用HPLC法同时测定复方磺胺甲噁唑颗粒剂中磺胺甲噁唑(SMZ)和甲氧苄啶(TMP)的含量。方法:色谱柱为ODS C_(18)柱,4.6x150mm,流动相为甲醇-磷酸盐缓冲液(pH5.90)(20:80),检测波长为240nm。结果:线性范围分别为:SMZ 20～181μg·ml~(-1),(r=0.9999);TMP 4～38μg·ml~(-1),(r=0.9999)。平均回收率分别为:SMZ100.5％(RSD=0.29％);TMP 100.3％(RSD=0.51％)。结论:本法分离度好,快速,简便,可同时测定该品中的两种组分。     

复方磺胺甲噁唑片溶出度考察

目的:建立准确、快速的溶出度测定方法,有效地控制复方磺胺甲噁唑片的溶出度。方法:紫外双波长分光光度法。结果:线性范围为磺胺甲噁唑2.548～12.74μg/ml(r=0.9998)、甲氧苄啶1.201～6.005μg/ml(r=0.9997);平均回收率(x±RSD)％分别为:磺胺甲噁唑(100.2±0.33)、甲氧苄啶(100.3±1.12)。结论:本方法能有效地控制复方磺胺甲噁唑片的质量。     

HPLC法同时测定复方磺胺甲噁唑片中磺胺甲噁唑和甲氧苄啶的含量△

目的:建立并优化同时测定复方磺胺甲噁唑片中磺胺甲噁唑和甲氧苄啶的含量的高效液相色谱方法。方法:采用Diamonsil-C18(150mm×4.6mm,5μm)色谱柱,乙腈-0.1%三乙胺水溶液(磷酸调pH至6.0)(80:20v/v)为流动相,流速为1.0ml.min-1,检测波长为240nm。结果:磺胺甲噁唑与甲氧苄啶分别在为10～100μg.ml-1(r=0.9995)和2～20μg.ml-1(r=0.9993)范围内线性关系良好,平均回收率(n=9)分别为97.6%和99.7%,仪器精密度的RSD分别为1.7%和1.4%,并采用以上方法对市售复方磺胺甲噁唑片中的磺胺甲噁唑和甲氧苄啶进行含量测定。结论:本方法较已报道的方法更加准确、快速,灵敏度更高,可为复方磺胺甲噁唑片的质量控制提供更为可靠的方法。     

毛细管电泳法测定复方磺胺甲噁唑混悬液中两组分含量

目的测定复方磺胺甲噁唑混悬液中磺胺甲噁唑及甲氧苄啶的含量,建立药物分析方法.方法采用高效毛细管区带电泳法,磺胺嘧啶为内标,运行缓冲液为0.05 mol·L-1乙酸钠缓冲液(pH 5.0);运行电压15 kV;检测波长240 nm.并与药典规定的方法相比较.结果磺胺甲噁唑和甲氧苄啶在7～15 min内完全分离,线性范围分别为50.7～253.7 mg·L-1(r=0.998 3)和10.1～50.5 mg·L-1(r=0.999 5),平均回收率分别为96.5%(RSD为2.72%)和98.0%(RSD为1.15%).结论毛细管电泳法结果可靠、简便快速、节约试剂,适用于复方磺胺甲噁唑混悬液的含量测定.     

一阶导数光谱法测定复方磺胺甲唑片中磺胺甲唑和甲氧苄啶含量

目的:建立测定复方磺胺甲噁唑片中磺胺甲噁唑和甲氧苄啶含量的简便方法.方法:采用一阶导数光谱法测定,磺胺甲噁唑的测定波长为258.8nm,甲氧苄啶的测定波长为238.2nm.结果:磺胺甲噁唑和甲氧苄啶的线性范围分别为5μg/mL～50μg/mL(r=0.9998),6μg/mL～50μg/mL(r=0.9996);平均回收率分别为99.6%,98.5%.结论:本法简便、准确,可用于复方磺胺甲噁唑片的质量控制.     

复方磺胺甲噁唑混悬剂中磺胺甲噁唑与甲氧苄啶的含量测定

目的:测定复方磺胺甲(口恶)唑混悬剂中磺胺甲(口恶)唑与甲氧苄啶的含量.方法:色谱柱为C18柱,以磷酸盐缓冲液[取0.05 mol/L磷酸二氢钾溶液1 000 mL,加三乙胺7 mL,用磷酸调节pH值至(5.90±0.05)]-甲醇(75:25)为流动相,流速为1.0 mL/min,检测波长为240 nm.结果:磺胺甲(口恶)唑与甲氧苄啶的线性范围分别为21.5～150.7μg/mL和5.5～38.4μg/mL,平均回收率分别为99.94%(RSD=0.77%)和100.58%(RSD=0.81%).结论:该方法准确、快速、简便,适用于复方磺胺甲(口恶)唑混悬剂中磺胺甲(口恶)唑与甲氧苄啶的含量测定.     

转换曲线分光光度法测定复方磺胺甲噁唑片中磺胺甲噁唑与甲氧苄啶的含量

目的应用转换曲线分光光度法测定复方磺胺甲噁唑片中磺胺甲噁唑及甲氧苄啶的含量。方法取复方磺胺甲噁唑片样品和对照品磺胺甲噁唑及甲氧苄啶分别按规定的方法制成供试品溶液，于波长210～220／nm范围内，间隔1nm分别记录样品溶液和对照品溶液吸光度（A）值，计算各自吸光度的转换值，将两组吸光度转换值作线性回归，按转换曲线法计算样品溶液磺胺甲噁唑及甲氧苄啶的含量。结果样品溶液吸光度转换值与对照品溶液吸光度转换值成良好的线性关系，r=0．9966，样品测定其平均回收率为：磺胺甲噁唑（97．60±0．37）％，甲氧苄啶（98．7±0．28）％。结论转换曲线分光光度法测定复方磺胺甲噁唑片中磺胺甲噁唑及甲氧苄啶的含量快速可行。     

高效毛细管电泳法测定复方磺胺甲噁唑片中磺胺甲噁唑和甲氧苄啶的含量

目的　测定复方磺胺甲 口 恶 唑片中磺胺甲 口 恶 唑及甲氧苄啶的含量。方法　采用高效毛细管电泳法 ,肉桂酸为内标 ,运行缓冲液为 2 5mmol·L-1硼砂 硼酸缓冲液 (pH9.2 ) ,内含 3 0mmol·L-1十二烷基磺酸钠及 10 %乙腈 ;运行电压 2 0kV ;检测波长2 14nm。结果　磺胺甲口 恶 唑和甲氧苄啶线性范围分别为 5 0～ 2 5 0 μg/mL(r =0 .9997)和 10～ 5 0 μg/mL(r =0 .9986) ,平均回收率分别为 99.0 %和 98.6% ,RSD分别为 2 .0 %及 2 .6% (n =6)。结论　该方法简便、准确、灵敏 ,适用于复方磺胺甲 口 恶 唑片的质量控制     

高效液相色谱法测定复方磺胺甲噁唑分散片主要成分的含量

目的:采用高效液相色谱法测定复方磺胺甲噁唑分散片的含量.方法:以waters C18柱为分析柱;以水-乙腈-三乙胺(799:200:1)(用醋酸调pH至5.9±0.1)为流动相;检测波长:240 nm;流速:1.0 mLmin-1;柱温:30℃.结果:磺胺甲噁唑在162.1～810.4μg·ml-1范围内呈良好的线性,r=0.9999);平均回收率为98.83%(RSD=0.88%);甲氧苄啶在32.8～164 μg·ml-1范围内呈良好的线性,r=0.9999;平均回收率为98.48%(RSD=1.15%).结论:本方法操作简便,结果准确可靠,可用于复方磺胺甲噁唑分散片的质量控制.     

HPLC法测定复方磺胺甲恶唑糖浆中磺胺甲噁唑及甲氧苄啶的含量

目的建立高效液相色谱法测定复方磺胺甲噁唑糖浆中磺胺甲噁唑（SMZ）及甲氧苄啶（TMP）含量的方法。方法采用HPLC法,Zorbax C18色谱柱（4.6mm×150mm,5μm）;以水乙腈：三乙胺（799：200：1）（用1mol氢氧化钠溶液或冰醋酸调节pH为5.9）为流动相;流速1.2ml/min;柱温：30℃;检测波长：240nm;结果磺胺甲噁唑进样量在0.40～4.00μg范围内呈良好的线性,r=0.9999;平均加样回收率为98.63%,RSD=0.71%（n=9）;甲氧苄啶进样量在0.10～1.05μg范围内呈良好的线性,r=0.9998;平均加样回收率为102.55%,RSD=0.55%（n=9）。结论本方法简单,准确,可靠,可用于复方磺胺甲噁唑糖浆的质量控制。     

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.     

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.