HPLC法测定注射用盐酸头孢吡肟中头孢吡肟E-异构体的含量

目的：采用HPLC法测定注射用盐酸头孢吡肟中头孢吡肟E-异构体残留量。方法：色谱柱为Intersil C18柱（250 mm×4.6 mm,5μm）,流动相A为0.005 mol/L磷酸二氢铵溶液-乙腈（93∶7）,流动相B为0.005 mol/L磷酸二氢铵溶液-乙腈（70∶30）,线性梯度洗脱,流速1.0 ml/min,检测波长257 nm。结果：盐酸头孢吡肟E-异构体的线性范围为1.004~9.036μg/ml（r=0.999 8）;平均回收率为100.5%（n=9）,RSD为0.77%。结论：本法简便、快速、结果准确。     

HPLC测定注射用盐酸头孢吡肟的含量

目的采用RP-HPLC法测定注射用盐酸头孢吡肟的含量。方法色谱柱为Kromasil C18柱(250 mm×4.6 mm,5μm),流动相为戊烷磺酸钠溶液-乙腈(96:4),流速1.0 ml.min-1,检测波长254 nm。结果盐酸头孢吡肟的线性范围为100.08~150.12μg.ml-1(r=0.9998);平均回收率为99.57%,RSD=0.27%(n=9)。结论所建方法快速、简便、准确、重复性好,可用于注射用盐酸头孢吡肟的含量测定。     

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.     

高效分子排阻色谱法测定头孢克肟颗粒中聚合物的含量

目的建立高效分子排阻色谱法(HPSEC)测定头孢克肟颗粒中高分子聚合物的方法。方法采用HPLC,色谱柱为TSKgel G2000 SWXL(7.8 mm×300 mm,5μm),以磷酸盐缓冲液-乙腈(95∶5)为流动相,流速为0.6 mL·min^-1,柱温为20℃,检测波长为254 nm,进样体积为20μL。结果高分子聚合物峰与头孢克肟峰能有效分离,辅料无干扰,头孢克肟主峰的线性范围为0.153~20.635μg·mL^-1(r=0.9999),检测限为0.05μg·mL^-1,定量限为0.15μg·mL^-1;方法中样品测定的重复性(RSD=0.5%)与精密度(RSD=1.4%)良好;供试品溶液和对照品溶液,25℃条件下24 h保持稳定。微调方法中的流速、柱温和流动相比例,对检测结果无影响。结论此方法简便,耐用性好,灵敏度高,重复性好,可用于头孢克肟颗粒中高分子聚合物的含量检测。     

SPE-HPLC法测定人血浆中头孢吡肟的浓度

目的:建立测定人血浆中头孢吡肟浓度的方法.方法:采用固相萃取(SPE)血浆中头孢吡肟.色谱柱为大连依利特Hypersil BDS C18,流动相为甲醇-磷酸盐缓冲液(20:80),柱温为30℃,流速为1 ml·min-1,检测波长为257 nm,进样量20 μl.结果:头孢吡肟检测浓度线性范围为1.0～200 mg·L-1(r＝0.999 9);最低检测限为1 mg·L-1;低、中、高3种浓度头孢吡肟的方法回收率分别为118.0%,97.0%,95.0%,日内RSD分别为1.7%,3.6%,2.1%,日间RSD分别为8.2%,4.9%,2.6%.结论:该方法简便、灵敏度高,适用于测定人血浆中头孢吡肟的含量.     

凝胶色谱法测定头孢克肟缓释微丸胶囊中高分子聚合物

目的建立凝胶色谱法测定头孢克肟缓释微丸胶囊中的高分子聚合物。方法选用Sephadex G-10柱(400 mm×13 mm,40¹20μm)色谱柱,流动相A为p H=7.0的0.01 mol·L-1磷酸盐缓冲液,流动相B为水,流速为1.0 m L·min-1,检测波长为254 nm,进样量为20μL。结果头孢克肟缓释微丸胶囊中高分子聚合物在0.515120μm)色谱柱,流动相A为p H=7.0的0.01 mol·L-1磷酸盐缓冲液,流动相B为水,流速为1.0 m L·min-1,检测波长为254 nm,进样量为20μL。结果头孢克肟缓释微丸胶囊中高分子聚合物在0.515².013 mg·m L-1与峰面积呈良好的线性关系(r=0.999 7),头孢克肟缓释微丸胶囊中高分子聚合物含量<0.1%。结论该方法简便、准确、灵敏度高,适用于头孢克肟缓释微丸胶囊中高分子聚合物的控制。     

HPLC—CDD法测定盐酸头孢吡肟及其制剂中的N-甲基吡咯烷的含量

目的建立高效液相-电导法(HPLC-CDD法)测定盐酸头孢吡肟中N-甲基吡咯烷含量的方法。方法以羧酸基键合硅胶为分析柱的填充剂metrosep C2(100mm×4.0mm,7μm);流动相为0.01mol/L硝酸溶液∶乙腈(99∶1);流速1ml/min;柱温35℃;进样量20μl;检测器:电导检测器。结果N-甲基吡咯烷在4.8~38.8μg/ml浓度范围与峰面积呈良好的线性关系,r=0.9999。高、中、低三种浓度的平均回收率为101.2%,RSD为1.3%。结论该方法简便、准确、灵敏度高,重现性好,可作为盐酸头孢吡肟中的N-甲基吡咯烷的含量测定方法。     

高效液相色谱法测定头孢克肟颗粒的溶出度

目的采用高效液相色谱(HPLC)法测定头孢克肟颗粒的溶出度。方法采用Waters Sunfire C18色谱柱(4.6 mm×250 mm,5μm);流动相为四丁基氢氧化铵溶液(取10%四丁基氢氧化铵溶液25 mL,加水1 000 mL,摇匀,用1.5 mol·L-1磷酸溶液调节pH至7.0)-乙腈(72∶28);检测波长288 nm;进样量20μL。结果头孢克肟在8～160μg·mL-1范围内呈良好线性关系,r=0.999 9,平均回收率为99.67%,RSD为0.56%(n=9)。结论该方法简单,能准确测定头孢克肟颗粒的溶出度,专属性良好。     

LC-MS测定双氢青蒿素哌喹片中阿莫西林、头孢克洛和头孢克肟的残留量

目的 建立双氢青蒿素哌喹片中阿莫西林、头孢克洛、头孢克肟残留量的液质联用检测方法。方法 采用Thermo Gold C₁₈色谱柱(2.1 mm×50 mm,1.9μm);流动相为10 mmol·L^-1乙酸铵溶液(A)-乙腈(B)。阿莫西林、头孢克洛稀释剂为10 mmol·L^-1乙酸铵溶液(氨水调节pH值至7.2),流速为0.3 mL·min^-1,进样量为10μL;头孢克肟稀释剂为10 mmol·L^-1乙酸铵溶液(氨水调节pH值至11.0),流速为0.25 mL·min^-1,进样量为2μL。阿莫西林、头孢克洛和头孢克肟分别采用2种梯度洗脱条件。结果 阿莫西林、头孢克洛和头孢克肟线性良好,线性方程分别为y=3 734.53x–2 188.63(r=0.999 5),y=1 396.67x–266.554(r=0.999 8)和y=3 636.39x+2 277.48(r=0.999 7),重复性RSD分别为3.1%,2.8%,2.2%,回收率分别为107.1%...     

反相高效液相色谱法测定头孢克肟口含片中头孢克肟的含量

目的:建立RP-HPLC测定头孢克肟口含片中头孢克肟含量的方法。方法:色谱柱为ReliaSil C_18(250 mm×4．6 mm, 5μm),流动相为四丁基氢氧化铵溶液(用1．5 mol·L~(-1)磷酸溶液调节pH至7．0)-乙腈(70:30),检测波长254nm。流速0．8 ml·min~(-1)。结果:头孢克肟浓度在2-120μg·ml~(-1)范围内,与峰面积呈良好的线性关系,r=0．999 9;平均回收率为100．6％(n= 9),RSD=1．4％。结论:该方法简便可靠,可用于头孢克肟口含片的质量控制。     

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.     

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.