HPLC测定安乃近片中的安乃近和4-N-去甲安乃近

目的采用HPLC法同时测定安乃近片中的安乃近及4-N-去甲安乃近。方法采用Shim-pack VP C18色谱柱(150mm×4.6 mm,5μm),流动相为甲醇-水-冰醋酸(45:55:0.5),检测波长251 nm。结果安乃近和4-N-去甲安乃近的线性范围分别为2.00~100.20μg.ml-1(r=0.9999)、0.08~105.10μg.ml-1(r=0.9999)。平均回收率分别为100.07%、RSD=0.56%(n=6)和100.33%、RSD=0.75%(n=6)。结论所建方法快速、准确,能有效控制安乃近片的质量。     

HPLC法测定安乃近片的含量

目的建立HPLC法测定安乃近片的含量。方法采用KromasilC18柱（250.0mm×4.6mm,5μm）,以磷酸盐缓冲液（pH为7.0）-甲醇（72：28）为流动相,UV检测波长254nm,流速1.0mL/min。结果安乃近在104.4～417.6μg/mL范围内呈良好的线性关系（r=0.9999）,平均回收率为99.7%,RSD=0.64%。结论本法测定安乃近片的含量科学、准确、简便,可用于安乃近片的质量控制。     

柱前衍生化HPLC法测定安乃近中甲醛的含量

目的:建立一种测定安乃近中甲醛含量的HPLC方法。方法:甲醛与衍生溶液形成衍生物后用HPLC方法进行分析检测。采用C18柱(5μm,4.6mm×250mm),以28体积的甲醇和72体积的缓冲溶液(6.0g/L磷酸二氢钠溶液1000mL,加1mL三乙胺,加氢氧化钠溶液调pH至7.0)的混合液为流动相,检测波长为412nm,流速为1.0mL/min,柱温为30℃。结果:在0.11μg/mL~3.15μg/mL范围内,线性关系(R~2=0.999,n=6)良好,平均回收率为101.9%,RSD为5.7%。结论:本方法灵敏,准确,可以用于安乃近中甲醛含量的检测。     

HPLC法测定安乃近片的含量

目的:建立专属性强的HPLC法测定安乃近片含量。方法:采用DiamonsilTMC18(200mm×4.6mm,5μm),以甲醇-缓冲液(磷酸二氢钠6.0g,加水溶解并稀释至1000ml,加三乙胺1ml,用浓氢氧化钠溶液调节pH值至7.0)(28∶72)作为流动相,检测波长为264nm,流速:1.0ml·min-1。结果:本色谱条件能将安乃近与4-去甲基安乃近及其他降解产物有效分离;在52.6～526μg·ml-1范围内,色谱峰面积与浓度呈良好的线性关系,r=0.99995;平均回收率为100.6%,(RSD=0.74%,n=9)。结论:本法专属性强、准确、简便,可供作为安乃近片含量修订的参考,尤其适用于疑似掺假安乃近片的含量测定。     

安乃近片含量测定方法的探讨

目的:探讨安乃近片的含量测定方法.方法:采用紫外分光光度法测定安乃近片中安乃近的含量,测定波长为(257±1)nm.结果:安乃近在10～30μg·ml-1的浓度范围内,吸收度A与浓度C呈良好的线形关系(r=0.999 9,n=5),平均回收率为100.01%,RSD为0.91%(n=5).结论:紫外分光光度法干扰因素少,准确可靠,可用于安乃近片的含量测定.     

高效液相色谱法测定安乃近氯丙嗪注射液中盐酸氯丙嗪含量

目的 采用高效液相色谱法测定安乃近氯丙嗪注射液的含量.方法 采用C18色谱柱(250 mm×4.6 mm,5μm),流动相为0·1 mol/L磷酸二氢钾(用磷酸调节pH:3.0)-乙腈(55:45),检测波长254 nm,流速1.0 mL/min,进样量20μL,柱温35℃.结果 盐酸氯丙嗪质量浓度在4.99-49.91μg/mL范围内与峰面积呈良好线性关系,r=0.9999(n=8).结论 所建立的方法灵敏、准确、简便,可作为安乃近氯丙嗪注射液的含量测定方法.     

流动注射分析法测定安乃近片的含量

用单流路流动注射分析法测定安乃近片(Metamizole sodium Tablets)中安乃近(Metamizole Sodium)的含量。具还原性的安乃近与氧化剂硫酸铁铵作用生成的绿蓝色中间体在604nm有最大吸收。0.3%的硫酸铁铵作载液,进样频率280样/h,安乃近线性范围10～100μg(r=0.9995),平均回收率为100.06%,RSD0.30%。测定结果与中国药典法测定结果经t检验比较,无显著性差异。     

差示分光光度法测定安乃近片的含量

目的:建立测定安乃近片含量的新方法。方法:采用差示分光光度法。以0.1mol.L-1盐酸溶液为介质制备参比液,以0.1mol.L-1氢氧化钠溶液为介质制备样品液,通过在波长283nm处,测定2种溶液的差示吸收值直接测定安乃近的含量,并将结果与其他方法(紫外分光光度法、高效液相色谱法和碘量法)比较。结果:安乃近检测浓度线性范围为10.35～51.75μg.L-(1r=0.9998),平均回收率为99.94%,RSD=0.27%(n=5);4种方法含量测定结果基本一致。结论:建立的新方法测定结果准确,方法简便、专属性强,可用于该制剂的含量测定。     

安乃近片的HPLC测定法研究

目的:针对安乃近易水解的问题,着重研究溶媒、流动相对其稳定性的影响,建立安乃近片新的高效液相色谱测定法;方法:在溶媒中加入2%的亚硫酸钠作为稳定剂,色谱柱为Diamonsil (钻石)C18(4.6 mm×150 mm,5 μm);以甲醇-0.025 mol·mL-1磷酸盐缓冲液(取磷酸二氢钾3.402 g,加水至1 000 mL,用三乙胺调pH=6.5)(35∶65)为流动相;流速1.0 mL·min-1;检测波长为228 nm;按外标法测定安乃近片的含量.结果:供试液在4h内稳定;安乃近浓度的线性范围为0.1～2.0 g·L-1,Y=16 051x+40.517,R=1.000 0;最低检测限为3 mg·L-1;含量测定结果与滴定法一致.结论:本法简便易行,结果准确可靠、重现性好、专属性强.     

高效液相色谱法测定安乃近片的含量

目的建立测定安乃近片含量的高效液相色谱（HPLC）法。方法采用C—S柱（250mm×4．6mm，5μm），以甲醇-0．05mol／L磷酸二氢钾（30：70）为流动相和溶剂，265nm为检测波长，流速1．0mL／min。结果安乃近与4-N-去甲基安乃近等降解产物能有效分离，安乃近质量浓度在2．55～12．75μg／mL范围内与峰面积线性关系良好，平均回收率为99．7％，RSD为0．45％（n=9）。结论HPLC法准确、简便、快速，适于安乃近片的含量测定及其杂质的分离。     

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.     

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.