紫外分光光度法测定双苯氟嗪片的含量、含量均匀度及溶出度

目的:建立紫外分光光度法测定双苯氟嗪片含量、含量均匀度及溶出度的方法.方法:采用紫外分光光度法测定含量、含量均匀度和溶出度.溶剂为0.1 mol·L-1的盐酸溶液;测定波长为248 nm;含量及含量均匀度的测定浓度为12.5 μg·mL-1,溶出度的测定浓度为10μg·mL-1.采用对照品比较法计算含量、含量均匀度和溶出度.结果:双苯氟嗪在4～28 μg·mL-1的范围内线性关系良好,r=0.999 9(n=7).平均回收率为99.7%,RSD为0.16%(n=9).结论:该法简便,准确,可作为双苯氟嗪片含量、含量均匀度及溶出度的测定方法.     

紫外分光光度法测定草酸右旋依地普仑片的溶出度

目的:建立测定草酸右旋依地普仑片溶出度的方法。方法:采用紫外分光光度法在239nm波长处测定其吸收度,并计算回收率和溶出度。结果:草酸右旋依地普仑检测浓度在2.5~30μg.mL-1范围内与吸收度呈良好线性关系(r=0.9999),平均回收率为100.64%(RSD=0.49%);3批样品的30min溶出度均在90%以上。结论:本方法简便、准确,结果可靠,可用于草酸右旋依地普仑片的溶出度测定。     

自身对照法测定复方黄连素片溶出度

目的:建立自身对照法测定复方黄连素片溶出度。方法:采用自身对照法(UV)测定复方黄连素片的溶出度。采用篮法,溶出介质为纯化水(900 mL),转速100 r.min-1,取样时间90 min。结果:复方黄连素片溶出度测定自身对照法在1.2～9.0μg.mL-1浓度范围内呈线性(r=0.9995,n=5),回收率98.9%,RSD=0.03%。结论:本法简便、准确、可行,可作为复方黄连素片的质量标准中控制项目之一。     

紫外分光光度法测定盐酸法倔唑片的溶出度

目的:建立测定盐酸法倔唑片溶出度的方法。方法:采用紫外分光光度法,以水为溶媒,在280nm波长处测定其吸收度,并计算溶出度。结果:盐酸法倔唑的线性范围为1～10μg.mL-1(r=0.9999),平均回收率为99.38%(RSD=0.33%);3批样品的30min溶出度均在90%以上。结论:本方法简便、准确,结果可靠,可用于该制剂的溶出度测定。     

土霉素片溶出度测定方法研究

目的:建立土霉素片溶出度的测定方法。方法:在检测波长271nm下用紫外分光光度法测定土霉素含量;以0.01mol·L-1盐酸溶液作溶剂,选用桨法测定土霉素片溶出度。结果:土霉素检测浓度线性范围为4～32IU·mL-(1r=0.9999)。平均回收率为100.1%(RSD=0.65%);45min时样品溶出度均在75%以上。结论:所建立方法可用于土霉素片溶出度测定。     

高效液相色谱法测定复方对乙酰氨基酚片的含量和溶出度

目的:建立测定复方对乙酰氨基酚片含量和溶出度的方法。方法:采用高效液相色谱法。色谱条件:采用SHIMADZUShim-pack C18色谱柱,流动相为甲醇-0.1%醋酸钠溶液(冰醋酸调节pH 3.5)(30∶70),流速1.0 mL.min-1,检测波长272nm。按中国药典桨法,采用ZRS-8G智能溶出仪,以0.1 mol.L-1盐酸溶液为溶出介质测定溶出度。结果:对乙酰氨基酚、咖啡因、阿司匹林线性范围分别为6.462～161.55μg.mL-1(r=0.9999),1.577～39.42μg.mL-1(r=0.9999),11.04～276.1μg.mL-1(r=0.9999);回收率(n=5)分别为100.1%,100.4%,99.8%,RSD分别为0.53%,0.70%,0.55%。样品溶出度均一性好,在30 min时3个组分溶出度均达到80%。结论:本方法准确、方便,结果满意,适用于复方对乙酰氨基酚片的含量和溶出度测定。     

HPLC法测定盐酸左旋咪唑片的含量及溶出度

目的:建立HPLC法测定盐酸左旋咪唑片的含量及溶出度.方法:盐酸左旋咪唑含量用HPLC法测定,溶出度测定照<中国药典>2005年版二部附录溶出度测定法第一法进行.结果:盐酸左旋咪唑平均回收率99.2%,RSD为0.6%(n=6)溶出量大于标示量的90%.结论:方法简便适用于盐酸左旋咪唑片的质量控制.     

HPLC法测定麦角隐亭咖啡因片的溶出度和含量均匀度

目的:建立一种比比色法更简便、准确的方法(HPLC法)来测定洛斯宝片的溶出度和含量均匀度.方法:采用反相高效液相色谱法,用外标法测定洛斯宝片的溶出度和含量均匀度.用十八烷基硅烷键合硅胶为填充剂,以磷酸二氢铵-乙腈(用磷酸调节pH 2.0)=70:30为流动相,流速1.2 mL·min-1,于290 nm波长处检测,按外标法以峰面积计算其含量及每片的溶出量.结果溶出度的线性回归方程为:y=6 152x-2 743.7,r=0.999 9(n=5),平均回收率为100.6%,RSD为0.6%(n=9);含量均匀度的线性回归方程为:y=7 285.2x-334.65,r=1(n=5),平均回收率为98.5%,RSD为0.4%(n=9).结论:实验证明该法简便快捷,能准确地测定产品的溶出度和含量均匀度.     

紫外分光光度法测定苯甲酸利扎曲普坦片的溶出度

目的:建立测定苯甲酸利扎曲普坦片溶出度的方法。方法:采用紫外分光光度法在280nm处测定其吸收度,并计算溶出量。结果:苯甲酸利扎曲普坦检测浓度在2.5~30μg/ml范围内线性关系良好(r=0.9 999),平均回收率为99.18%(RSD=0.25%),3批样品的30min溶出度均在90%以上。结论:本方法简便、准确,结果可靠,适用于苯甲酸利扎曲普坦片的溶出度测定。     

琥珀酸西苯唑啉片溶出度的测定

目的:建立测定琥珀酸西苯唑啉片溶出度的方法。方法:采用高效液相色谱法按峰面积外标法测定及计算药物含量,色谱柱为Diamonsil C18,流动相为乙腈-磷酸(40∶60),检测波长为230nm;选用桨法测定溶出度。结果:琥珀酸西苯唑啉检测浓度线性范围为1～40μg·mL-1(r=0.9999);平均回收率为97.70%(RSD=0.14%);3批样品15min时溶出度均在80%以上。结论:所建立的溶出度测定方法简便、快捷,结果准确,可用于琥珀酸西苯唑啉片溶出度的测定。     

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.