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.     

注射用盐酸头孢甲肟含量测定及有关物质检查方法的研究

目的用HPLC法测定注射用盐酸头孢甲肟中头孢甲肟的含量及有关物质。方法采用ODS C18(200mm×4.6mm,5μm)色谱柱,流动相采用水∶冰乙酸∶乙腈(850∶17∶150),流速1.0ml/min,检测波长254nm。结果溶液浓度在0.06~500μg/ml范围内线性良好,r=0.9997(n=12),方法平均回收率为99.87%,RSD为0.36%(n=9)。盐酸头孢甲肟杂质数目为14至15个,总量为1.00~1.58%。结论本法简便、准确、灵敏度高,可用于注射用盐酸头孢甲肟的含量和有关物质检查,亦可以进行稳定性研究中降解产物的色谱检查。     

高效液相色谱法测定注射用盐酸头孢吡肟中精氨酸含量

目的 改进中国药典2010年版中注射用盐酸头孢吡肟中精氨酸的含量测定方法.方法 采用Agilent Extend-C18柱（5μm,4.6×250mm）,含0.015mol·L-1辛烷磺酸钠的0.1mol·L-1的磷酸二氢钠 （用氢氧化钠试液调节pH值至5.0）-甲醇（94：6）为流动相,流速：1.0mL·L-1,检测波长206nm,精氨酸浓度为0.1mg·mL-1,柱温控制在40℃.结果 克服了原方法中精氨酸峰形严重拖尾问题;本方法中精氨酸在0.3μg～1.4μg范围内,线性关系较好（r=0.9977）,平均回收率为99.17%,RSD为1.8%.结论 方法可用于注射用盐酸头孢吡肟中精氨酸的含量测定,结果准确可靠.     

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-ELSD法测定β-内酰胺类抗生素注射剂中精氨酸的含量

目的 建立高效液相色谱-蒸发光散射检测法(HPLC-ELSD)分析β-内酰胺类抗生素注射用制剂中精氨酸的含量.方法 采用Agilent Zorbax SB-C18(4.6mm×250mm, 5μm)色谱柱,流动相为0.1%三氟乙酸溶液:乙腈(80:20),流速为0.8ml/min,漂移管温度为45℃,雾化气体压力为3.5bar.结果 供试品中精氨酸与抗生素主药及相关杂质分离良好,在10.27～314μg/ml的范围内呈较好的线性关系(r=0.99986),在盐酸头孢吡肟中的平均回收率为101.5%, RSD为2.1%(n=9);在氨曲南中的平均回收率为97.8%, RSD为1.8% (n=9);在头孢拉定中的平均回收率为95.6%, RSD为1.9%(n=9).以注射用盐酸头孢吡肟为例进行重复性试验,结果测得含精氨酸均值为37.0%, RSD为1.9%(n=9),灵敏度试验测得方法的检测限和定量限分别为2和10μg/ml.结论 本法专属、快捷,结果准确,重现性好,可以作为部分β-内酰胺类抗生素注射用制剂中添加的活性物质精氨酸的含量测定方法.     

注射用盐酸头孢甲肟的杂质谱研究

目的 建立UHPLC-TOF-MS法对注射用盐酸头孢甲肟的杂质结构进行研究。方法 采用UHPLC-TOF-MS联用,Waters UPLC HSS T3色谱柱(2.1 mm×100 mm,1.8μm),流动相A为0.1%甲酸,流动相B为乙腈,梯度洗脱,柱温40℃,流速为0.3 mL·min^–1。结果 注射用盐酸头孢甲肟中检出15个有关物质,并对各杂质的结构进行了推测。结论 本实验建立的UHPLC-TOF-MS方法可用于注射用盐酸头孢甲肟的杂质谱研究。     

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人血浆中头孢吡肟浓度及其药动学

目的建立人血浆中头盐酸孢吡肟浓度的HPLC-UV测定方法,研究静脉注射盐酸头孢吡肟在健康人体中药动学行为。方法血浆经高氯酸沉淀蛋白后进行HPLC-UV分析,色谱柱为岛津Sh im-pack ODS,5μm,250 mm×4.6 mm I.D,流动相为0.025 mol/L的NaH2PO4∶乙腈(89∶11),磷酸调pH=3.0,流速1.0 mL/m in,紫外检测波长270 nm.测定健康志愿者30 m in内静滴盐酸头孢吡肟500 mg及停药后12 h的血药浓度-时间过程。结果头孢吡肟在血浆中的线性范围为0.2~50.0μg/mL,LLOQ为0.2μg/mL,批内和批间的精密度(RSD)均小于10%,准确度(Relative error,R.E)为-3.48%~0.06%.血浆中回收率大于85%.健康志愿者单次静滴500mg盐酸头孢吡肟30 m in后,实测得tm ax和Cm ax分别为(0.51±0.02)h和(24.96±3.50)μg/mL,估算的t1/2β和MRT分别为(2.03±0.18)h和(2.65±0.29)h,V1和CL分别为(0.168±0.068)L/kg和(0.207±0.026)L/(kg.h),AUC0-∞为(50.88±6.10)μg.h/mL。结论该方法经考察符合生物样品的测定要求,可应用于人血浆中头孢吡肟血药浓度的测定和药代动力学研究,盐酸头孢吡肟在中国人和美国人中的动力学行为相近。     

离子交换色谱法测定注射用盐酸头孢吡肟含量

目的 用离子交换色谱法(ICE)测定头孢吡肟含量.方法 采用Partisil SCX 10 μm柱(250 mm×4.6 mm).以5×10-4 mol/L (NH4)2SO4水溶液-乙腈(90∶10)为流动相,于258 nm波长处检测,流速为1.0 ml/min,柱温40℃.结果 盐酸头孢吡肟在8.520～4.260 μg/ml浓度范围内,峰面积与浓度呈良好线性关系(r=0.99997). 平均回收率为100.7%,相对标准偏差值(RSD)为0.43%.结论 该方法准确、专属、快速,可用于测定盐酸头孢吡肟的含量,及有关物质检查.     

注射用盐酸头孢吡肟的稳定性研究

目的:考察注射用盐酸头孢吡肟的稳定性.方法:采用高效液相色谱法测定其中盐酸头孢吡肟及有关物质的含量.以戊烷磺酸的水溶液(戊烷磺酸钠2.61 g→1000 mL水,冰醋酸调节pH=3.4,氢氧化钠调节pH=4.0)-乙腈(950:50)为流动相,检测波长为254 nm.结果:与放置0 d时比较,室温放置6个月后3批样品的各项指标均无明显变化.结论:注射用盐酸头孢吡肟的稳定性良好.     

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.

---

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.