采用HPLC法测定注射用头孢美唑钠中的有关物质

目的 建立注射用头孢美唑钠有关物质的测定方法.方法 采用反相-HPLC方法,色谱柱为XBridge Shield RP18柱(250mm×4.6mm,5μm);流动相为0.05mol/L醋酸铵溶液(用冰醋酸调节pH值至4.5)-甲醇(80:20);检测波长254nm;流速为0.8mL/min;柱温:25℃.结果 在该色谱条件下,已知杂质5-巯基-1-甲基四氮唑与其它杂质、各杂质峰与主峰之间的分离均良好,头孢美唑钠和5-巯基-1-甲基四氮唑的检测限均为2ng,在o.5～50μg/mL的浓度范围内,头孢美唑钠和5-巯基-1-甲基四氮唑的线性均良好,r分别为0.9999和0.9999.结论 该方法操作简便,结果准确、灵敏,可用于注射用头孢美唑钠中包括特异杂质5-巯基-1-甲基四氮唑在内的有关物质的测定.     

注射用头孢美唑钠的有关物质方法学研究

目的:建立HPLC法检查注射用头孢美唑钠有关物质的方法。方法:采用Agela XBP-C184.6mm×250mm5μm,以磷酸二氢铵溶液(5.75g磷酸二氢铵溶解在700ml水中,加25%四丁基氢氧化铵5.1ml)-甲醇-四氢呋喃(700:280:25)的混合溶液(用10%磷酸调pH4.5±0.1)为流动相,检测波长为214nm。结果:TMT和头孢美唑钠峰与相邻杂质峰分离度良好;在浓度3.2736μg/ml～4.9104μg/ml范围内,TMT浓度与峰面积呈良好的线性关系;TMT平均加样回收率为98.78%,RSD为0.12%。结论:本方法简便、快速、灵敏,可有效检测注射用头孢美唑钠中的有关物质。     

Sephadex G-10凝胶色谱系统测定头孢美唑钠的聚合物

目的建立凝胶色谱法测定头孢美唑钠的聚合物的方法。方法色谱柱为葡聚糖凝胶Sephadex G-10(16mm×35cm),流动相A:0.02mg.mL-1磷酸盐缓冲液(pH7.0);流动相B:水。流速为1.0mL.min-1。检测波长为254nm,进样量为200μl。结果头孢美唑钠在5.0~60.0mg.mL-1范围内,浓度与聚合物的峰面积呈良好的线性关系(r=0.9996)。结论该方法简便,准确,灵敏度高,重现性好。     

反相高效液相色谱法测定注射用苯唑西林钠有关物质

目的建立RP-HPLC法测定苯唑西林钠的有关物质。方法采用C18色谱柱;流动相:0.01 mol.L-1醋酸铵溶液(醋酸调pH至5.0)-乙腈(75∶25);流速:1.0 mL.min-1;检测波长:225 nm;柱温:30℃。结果苯唑西林钠线性范围为1.171~28.11μg.mL-1,r=0.999 8,检测限:0.036μg.mL-1,苯唑西林钠能与各杂质完全分离。结论建立的苯唑西林钠有关物质的测定方法简单、快速、重现性好。     

HPLC法测定注射用头孢他美钠的含量及有关物质

目的 建立高效液相色谱法测定注射用头孢他美钠的含量和有关物质.方法 采用Thermo Hypersil BDS C18柱(250mm×4.6mm,5μm),以0.013mmol/L庚烷磺酸钠、0.02mol/L磷酸二氢钾溶液-甲醇(75:25,用10％磷酸调pH值至3.4)为流动相;检测波长为263nm;柱温为35℃;结果 头孢他美钠浓度在0.1～402.4μg/mL范围内,峰面积与浓度线性关系好r=0.9999(n=8),最低检出限为0.4ng(S/N=3),定量限为2ng(S/N=10).结论 该法简便、准确、灵敏度高,专属性强,可以用于注射用头孢他美钠含量测定和有关物质检查.     

HPLC法测定兰索拉唑片含量及有关物质

建立高效液相色谱法测定兰索拉唑片含量及有关物质的方法。方法采用C18色谱柱(4.6mm×250mm,5μm),以水-乙睛-三乙胺(60∶40∶1)用磷酸调pH7.0为流动相,流速:1.0mL.min-1,检测波长为285nm,进样量20μL,柱温35℃。结果兰索拉唑浓度在19.76~177.84μg.mL-1时,其峰面积与浓度的线性关系良好(r=1);平均回收率为99.6%,平均相对标准偏差RSD为0.5%;检测限为0.02ng.mL-1。结论本法快速、简便、准确,灵敏度高,适用于兰索拉唑片含量及有关物质测定。     

HPLC法测定脐带血中头孢美唑钠浓度及其在剖宫产产妇中的预防用药研究

目的:建立测定脐带血中头孢美唑钠浓度的方法,并探索头孢美唑钠作为剖宫产术前预防感染的抗生素通过胎盘的情况。方法:采用高效液相色谱(HPLC)法,色谱柱为Agilent Eclipse XDB-C18,流动相为0.026 mol·L-1醋酸铵(pH 6.0)-甲醇(85∶15),流速为1.0 mL·min-1,检测波长为273 nm。选择11例健康的剖宫产产妇,术前静脉滴注头孢美唑钠2 g,于给药后不同时间点取脐带血,用HPLC法测定其浓度。结果:头孢美唑钠血药浓度在2.5～1 000μg·mL-1范围内线性关系良好(r=0.999 4);方法平均回收率为89.6%～106.0%;日内、日间RSD均<6%。开始静脉滴注头孢美唑钠后10 min～4 h内所取脐带血,浓度范围为3.81～25.52μg·mL-1。结论:本方法简便、准确、快速、稳定性好,为头孢美唑钠临床应用及药动学研究提供了理论依据。     

盐酸头孢吡肟的HPLC测定及有关物质检测

目的:建立盐酸头孢吡肟的HPLC测定及有关物质检测方法.方法:采用C18柱(250mm×4.6mm,5μm),流动相为乙腈-0.015mol·L-1戊烷磺酸钠(9:91,pH 4.0),检测波长为258nm,流速0.8mL·min-1.结果:盐酸头孢吡肟在9.4～1 202μg·mL-1浓度范围内,峰面积与浓度呈良好线性关系(r=1.000 0),平均回收率为(100.87±1.69)%,最低检测限为3.55ng.结论:本法简便、专属和重现性好,可用于测定盐酸头孢吡肟含量及有关物质.     

RP-HPLC法测定头孢他美钠的含量及有关物质

目的建立反相高效液相色谱法测定头孢他美钠的含量和有关物质。方法采用Hypersil BDS C18柱(250mm×4.6mm,5μm),以0.013mmol/L庚烷磺酸钠、0.02mol/L磷酸二氢钾溶液-甲醇(75:25,用10%磷酸调pH值至3.4)为流动相;检测波长为263nm;柱温为35℃。结果头孢他美钠浓度在0.1~335.2μg/mL范围内,峰面积与浓度线性关系好r=0.9999(n=8),最低检出限为0.0004μg(S/N=3),定量限为0.002μg(S/N=10)。结论该法简便、准确、灵敏度高,专属性强,可以用于头孢他美钠含量测定和有关物质检查。     

反相高效液相色谱法测定注射用卡络磺钠注射液的含量和有关物质

目的建立了注射用卡络磺钠的含量及有关物质测定的RP-HPLC方法。方法采用Hypersil C18色谱柱(4.6×250mm,10μm),以0.01mol.L-1磷酸二氢铵(3.0)-乙醇(92.5∶7.5)为流动相,检测波长:363nm。结果卡络磺钠在12.5~87.5μg.mL-1浓度范围内,峰面积与浓度呈良好线性关系(γ=0.9996),平均回收率为99.01%~99.50%,RSD=0.57%~0.98%。卡络磺钠及其有关物质得到基线分离,方法的最低检测量为2.5ng,控制总杂质量不得过1.0%。结论本法测定注射用卡络磺钠的含量及有关物质,方法简便、快速、结果准确,专属性好,适用于卡络磺钠及其制剂的质量控制。     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.     

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.