高效液相色谱法和紫外分光光度法测定利巴韦林含量比较

目的 :比较高效液相色谱法 (HPLC)和紫外分光光度法 (UV)测定利巴韦林葡萄糖注射液中利巴韦林含量。方法 :UV法测定条件 :λ =2 0 7nm ,溶剂为水 ;HPLC法测定条件 :C1 8柱 ,流动相为超纯水 ,流速 1mL·min 1 ,检测波长2 0 7nm。结果 :HPLC法和UV法的测定结果差异无显著性 ;结论 :HPLC法和UV法均可测定利巴韦林的含量 ,但HPLC法更准确、可靠。     

HPLC和络合-UV法测定特非那丁颗粒剂的含量

目的:用HPLC和电荷转移络合UV法分别测定特非那丁颗粒剂的含量,并对测定结果进行比较。方法:HPLC法,色谱柱:SpherisorbC8( 1 50×4 .6mm ,5μm) ;流动相:甲醇0 .1mol/L三乙胺磷酸缓冲液( 80∶2 0 ) ,检测波长2 3 5nm。电荷转移络合UV法,利用碘与TFN在氯仿中形成电荷转移络合物的原理,在紫外2 94nm的波长处测定TFN的含量。结果:两法测定的线性范围和平均回收率分别为:HPLC法1 50～1 50 0 μg/ml,99.4 0 % (RSD0.92%) ;络合UV法2～1 2 μg/ml,99.4 5% (RSD0.67%)。结论:两种测定方法准确可靠,并无显著性差异。     

维C银翘片中对乙酰氨基酚含量测定方法改进

目的:采用高效液相色谱法(HPLC)测定维C银翘片中对乙酰氨基酚的含量,以避免用双波长分光光度法测定时出现的干扰因素.方法:采用HPLC法,双波长分光光度法分别测定不同批号的维C银翘片中对乙酰氨基酚的含量.结果:双波长分光光度法较繁琐、误差大,HPLC法简便、快速、准确.结论:HPLC法准确可靠,适用于维C银翘片的质量控制.     

高效液相色谱法和紫外分光光度法测定呋喃西林含量的比较研究

目的 建立测定呋喃西林含量的高效液相色谱(HPLC)法,并与紫外-可见分光光度(UV)法进行比较。方法 HPLC法以十八烷基硅烷键合硅胶为填充剂,以0.125%三乙胺缓冲液-乙腈(85∶15)为流动相,流速为1 m L/min,检测波长为365 nm;UV法检测波长为375 nm。结果 HPLC法测得3份样品含量分别为标示含量的90.21%,90.73%,89.75%;UV法测得3份样品含量分别为标示含量的95.72%,94.09%,94.73%。结论 UV法比HPLC法测定样品的含量稍高,但HPLC法更适合作为呋喃西林溶液含量测定的方法。     

替硝唑氯化钠注射液含量测定的两种方法讨论

目的:用高效液相色谱法与紫外分光光度法测定替硝唑注射液的含量,对两种方法进行比较。方法:采用高效液相色谱(HPLC法),C18柱,以0.05mol/L磷酸二氢钾溶液:甲醇=80:20为流动相,检测波长为310nm;紫外分光光度(UV法),吸收波长为310nm。结论:紫外分光光度法可有效控制替硝唑的含量。     

两种不同方法测定注射用阿魏酸钠的含量

目的比较注射用阿魏酸钠含量的两种不同测定方法。方法分别采用紫外分光光度(UV)法及高效液相色谱(HPLC)测定。UV法采用纯化水为溶剂,310nm为测定波长;HPLC法采用Wa-tersXTerraRP18(4.6mm×250mm,5μm)色谱柱,流动相为甲醇-水(62∶38),流速为1ml/min,检测波长为310nm。结果 UV法中阿魏酸钠在6.216～14.504μg/ml范围内,浓度与吸光度呈良好线性关系(r=0.9999),平均回收率99.71%,相对标准偏差(RSD)为0.92%。HPLC法中阿魏酸钠在44.08～220.4μg/min范围内线性关系良好(r=0.9997),平均回收率98.79%,相对标准偏差(RSD)为1.61%。结论两种方法含量测定结果无明显差异,均可作为注射用阿魏酸钠含量测定的方法,可将UV法用于制剂半成品含量控制,而将HPLC法用于成品的含量控制,可缩短检验时间,保证制剂质量。     

UV法与HPLC法测定青蒿中青蒿素含量的比较

目的:分别以高效液相色谱(HPLC)法与紫外分光光度(UV)法测定青蒿中青蒿素的含量,比较2种方法分析结果的差异。方法:HPLC法中色谱柱为Kromasil ODS C18(250mm×4.6mm,5μm),流动相为甲醇-水(75:25),流速为1.0mL·min-1,检测波长为203nm,柱温为30℃。UV法中样品溶液用0.2%NaOH衍生后,在292nm波长处测定。结果:HPLC法标准曲线的线性范围为0.025～0.400mg·mL-1(r=0.9999),平均加样回收率为97.18%(RSD=3.58%,n=9);UV法标准曲线的线性范围为4～20μg·mL-1(r=0.9998)。UV法含量测定结果比HPLC法平均高出2.05倍。结论:HPLC法的精密度、稳定性、加样回收率都较好,对青蒿中青蒿素含量的分析较为准确。UV法不宜单独用于青蒿中青蒿素的含量分析。     

高效液相色谱法测定病儿氯硝西泮的血药浓度

目的 :建立测定血清中氯硝西泮血药浓度的高效液相色谱 (HPLC)法。方法 :血清中的氯硝西泮在弱碱性条件下经叔丁基甲醚提取 ,以α 溴苯乙酮为内标 ,流动相为甲醇∶乙腈∶正己烷 (5 5∶10∶35 ) ,紫外检测波长 2 30nm的RP/C18 HPLC测定。结果 :在 5～ 10 0 0 μg·L- 1范围内 ,氯硝西泮和内标的峰面积之比与浓度呈良好的线性关系 ,r =0 .9995 ,平均回收率大于 97% ,日内和日间RSD <5 %。结论 :采用反相HPLC法准确、灵敏、简便 ,适用于氯硝西泮的血药浓度测定及临床药动学研究。     

高效液相色谱法测定癣湿药水中蛇床子素的含量

目的测定癣湿药水中蛇床子素的含量.方法采用HPLC法,固定相为Spherisorb C18,流动相为甲醇-水(75:75,v/v),流速1.0 ml/min;紫外检测嚣,波长322 nm.结果线性范围为0.6～1.4μg,r=0.9990,平均回收率为97.36%,RSD为1.37%(n=6).结论该法快速、精确,可用于癣药水中蛇床子素含量的测定.     

HPLC法测定茜草双酯固体分散体中的有关物质

目的采用高效液相色谱法测定茜草双酯固体分散体中有关物质。方法采用HPLC法,色谱柱为C18色谱柱(250mm×4.6mm,5μm);柱温:室温;流动相为乙腈∶水=70∶30;流速为1.0mL/min;紫外检测波长:264nm。结果在该条件下,茜草双酯主峰和杂质峰得到很好的分离,最低检测限(S/N=3)为0.22ng;茜草双酯溶液在20℃避光条件下放置4h保持稳定。结论该方法准确、简便,灵敏度高,专属性强,可用于茜草双酯固体分散体中有关物质的测定。     

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.     

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.