拉呋替丁片溶出度测定方法研究

目的 建立拉呋替丁片溶出度的测定方法.方法 溶出方法采用中国药典溶出度第三法,以盐酸溶液(9→1 000)为溶出介质,转速为50 r·min-1,测定方法采用高效液相色谱法,用十八烷基硅烷键合硅胶为填充剂;以甲醇 1%醋酸铵溶液(冰醋酸调节pH值为5.7)(40∶60)为流动相;检测波长为279 nm,进样量 20 μl.结果 拉呋替丁在5～500 mg·L-1内呈良好的线性关系(r=0.999 8),RSD为0.47%(n=6).绘制的溶出曲线表明 30 min内拉呋替丁片可溶出 80%以上,确定的溶出时间为 30 min,限度为 80%.结论 该方法简单快速,准确稳定,可用于拉呋替丁片溶出度.     

塞克硝唑胶囊溶出度测定方法研究

目的 建立塞克硝唑胶囊溶出度测定方法.方法 采用高效液相色谱法(HPLC)测定塞克硝唑胶囊的溶出度.溶出条件为中国药典2005年版溶出度测定法第一法,溶出介质为盐酸溶液(1→1 000).结果 绘制的溶出曲线表明45 min内塞克硝唑胶囊可溶出80%以上,确定的溶出时间为45 min,限度为80%.结论 该法快速准确,...     

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.     

盐酸替扎尼定口腔崩解片溶出度的测定

目的建立盐酸替扎尼定口腔崩解片溶出度的测定方法。方法依照《中国药典》2000年版附录溶出度测定项下第一法,以水为溶出介质,转速为100 r.min-1,用HPLC法检测,检测波长为320 nm。结果在1~10μg.ml-1范围内,盐酸替扎尼定浓度与峰面积的线性关系良好(r=0.9999),高、中、低3种浓度的平均加样回收率为99.0%~99.4%,RSD为0.12%~0.15%;6批口腔崩解片样品的溶出度为92.0%~104.0%。结论所建方法操作简便、准确、可靠,适用于盐酸替扎尼定口腔崩解片的质量控制。     

复方酚苄明片中酚苄明溶出度测定方法的建立

目的：建立复方酚苄明片的溶出度测定方法.方法：采用《中国药典》2010年版二部附录溶出度第一法,溶出介质为0.1 mol·L-1盐酸溶液900ml,采用Hypersil BDS C18色谱柱（250 mm×4.6 mm,5 μm）,乙腈-0.7％磷酸水溶液（含0.5％三乙胺）（45∶ 55）为流动相,流速为1.0 ml·min-1,检测波长为267 nm.结果：酚苄明在5～60 μg·ml-1浓度范围内线性关系良好（r =0.999 9）,平均回收率99.8％（RSD =0.9％,n=9）.结论：该方法快速简便,准确,可用于复方酚苄明片中酚苄明溶出度的测定.     

盐酸氯吡格雷片溶出度方法研究

目的:建立盐酸氯吡格雷片溶出度测定方法。方法:根据《中国药典》2010年版溶出度测定方法中的第二法(桨法),以0.1mol·L-1盐酸溶液为溶出介质,转速为50r·min-1,于30min时取样,采用紫外分光光度法在波长270nm处测定吸光度并计算溶出度。结果:盐酸氯吡格雷检测浓度线性范围为50～320μg·mL-1(r=0.9998);平均回收率为99.46%,RSD=0.57%;3批样品溶出度30min时均在85%以上。结论:建立的溶出度测定方法准确、简便,可用于测定盐酸氯吡格雷片的溶出度。     

阿戈美拉汀片溶出度测定的方法研究

目的建立阿戈美拉汀片溶出度的测定方法。方法采用Phenomenex C18色谱柱(150 mm×4.6mm),流动相为乙腈-水(45∶55),检测波长为231 nm,流速为1 mL·min~(-1)。按《中国药典》2015年版二部附录ΧC溶出度测定第二法,采用溶出仪,通过对转速、取样时间、溶出介质的优化选择,确定阿戈美拉汀片溶出度的测定方法。结果阿戈美拉汀片的线性范围为0.0106～0.028 66 mg·mL~(-1),样品的溶出度均一性良好,以0.3%十二烷基硫酸钠为溶出介质,取样时间为30 min,转速为100r·min~(-1),溶出度均不低于80%。结论本法可用于阿戈美拉汀片溶出度的测定,能有效控制药品的质量,为提高阿戈美拉汀片的质量标准提供依据。     

氢溴酸加兰他敏分散片溶出度的测定方法

目的:研究并建立氢溴酸加兰他敏分散片溶出度测定方法.方法:按中国药典2000年版附录中溶出度项下第三法,分别以水、1%盐酸、5%乙醇等3种溶出介质进行氢溴酸加兰他敏分散片的溶出试验,采用HPLC法测定溶出介质中氢溴酸加兰他敏分散片的浓度.结果:在10～100μg·ml-1范围内,线性关系良好(r=0.999 7),平均回收率为100.2±1.30,RSD为1.5%.氢溴酸加兰他敏分散片30 min的溶出量大于标示量的90%.结论:所建立的溶出度测定法简单、准确、可靠,可作为控制氢溴酸加兰他敏分散片的质量标准之一.     

高效液相色谱法测定氟氯西林钠片的溶出度

目的:建立氟氯西林钠片溶出度的测定方法.方法:高效液相色谱法,色谱柱为Hypersil BDS C18柱(200mm×4.6mm, 5μm),流动相为0.02mol·L-1磷酸二氢钾缓冲液(用稀NaOH调节pH至5.0)-乙腈(70:30),检测波长为225nm,流速为1.0ml·min-1,柱温为25℃.照中国药典2005年版二部附录"溶出度测定法"第二法测定溶出度.结果:3批样品溶出量均为标示量的94%.结论:该法简便、准确,结果可靠.可用于氟氯西林钠片的溶出度测定.     

盐酸贝尼地平片溶出度的测定

目的:建立盐酸贝尼地平片溶出度的测定方法。方法:根据《中国药典》2005年版溶出度测定方法第三法(小杯法),以0.1mo·lL~(-1)盐酸为介质,转速为50r·min~(-1),于30min时取样,采用紫外分光光度法在359nm波长处测定吸光度,并计算累积溶出度。结果:盐酸贝尼地平检测浓度线性范围为5～30μg·mL~(-1)(r=0.9999);平均回收率为99.76%,RSD=0.47%;3批样品30min时累积溶出度均在80%以上。结论:所建立的溶出度方法简单、可靠,可用于盐酸贝尼地平片溶出度的测定。     

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.     

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.     

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.