HPLC法测定头孢特仑酯胶囊的含量和有关物质

建立HPLC法测定头孢特仑酯胶囊含量和有关物质的方法.采用 Hypersil ODS2柱,流动相为乙腈0.01mol·L-1醋酸醋酸钠缓冲液水(380∶100∶520),检测波长为254nm,流速为1.0mL·min-1.线性范围0.1038-1.038mg·mL-1,r=0.9999;平均回收率为100 3%(n-=9).方法快速、准确.     

LC-MS法鉴定头孢特仑新戊酯中的有关物质

目的建立鉴定头孢特仑新戊酯中有关物质的液相色谱-质谱联用分析方法,测定头孢特仑新戊酯原料药和制剂产品中的有关物质。方法采用Syncronis C18(250 mm×4.6mm,5μm)色谱柱,10mmol·L-1乙酸铵-乙腈(体积比50∶50)作为流动相等度洗脱分离;采集各有关物质的UV谱、一级和二级质谱图,并根据所得信息对有关物质进行结构分析。结果头孢特仑新戊酯原料药中检测到8种有关物质,分别为6种合成副产物、1种水解产物和1种降解产物;制剂产品中除原料药中的8种有关物质外,还检测到4种新的有关物质,分别为2种氧化产物、1种水解产物和1种降解产物。结论该方法灵敏度高,全面系统的阐述了头孢特仑新戊酯中的有关物质,为其质量控制和工艺优化提供了参考依据。     

反相高效液相色谱法测定盐酸头孢替安酯含量及有关物质

目的建立反相高效液相色谱法测定盐酸头孢替安酯的含量及有关物质。方法色谱柱为Hypersil C18柱(4.6mm×250mm,5μm),流动相:0.2mol.L-1磷酸二氢钾-乙腈-冰醋酸=72∶28∶1;流速:1mL.min-1,检测波长:254nm,柱温:25℃。结果盐酸头孢替安酯浓度在8～64μg.mL-1时,其峰面积与浓度的线性关系良好(r=0.999 2);平均加样回收率为100.0%,RSD为1.3%(n=6),其有关物质1、2、3的百分含量均低于日本药典15版规定值。结论本法快速、简便、准确、灵敏度高,适用于盐酸头孢替安酯原料药的含量及有关物质的测定。     

HPLC法测定头孢特仑酯片中主药的含量

目的:建立以高效液相色谱法测定头孢特仑酯片中主药含量的方法。方法:色谱柱为C18,流动相为乙腈-水(40:60),流速为1.2mL.min-1,柱温为40℃,检测波长为235nm,进样量为10μL。结果:头孢特仑酯检测浓度的线性范围为25～125μg.mL-1(r=0.9999,n=7);平均回收率为104.98%,RSD=0.86%。结论:本方法简便、快速、准确,可用于该制剂的质量控制。     

头孢特仑酯药物动力学及生物利用度研究

目的建立了人血浆中头孢特仑的HPLC方法,测定其片剂、干混悬剂的药物动力学参数及相对生物利用度。方法血样用甲醇沉淀、高速离心后进入液相分析,色谱柱:Agilent Zorbax C18(3.0 mm×150 mm,5μm),流动相为甲醇-水-HAC-TEA=35∶65∶0.6∶0.3,检测波长为262 nm。结果在0.047 5~4.75μg.mL-1峰面积值与浓度线性关系良好(r=0.999 9),定量下限为0.047 5μg.mL-1。绝对回收率为76.8%~83.3%。18名健康受试者随机交叉口服头孢特仑酯片剂、干混悬剂和进口头孢特仑酯片后,F0-τ分别为102.6%±13.4%和103.0%±8.8%。结论3种制剂生物等效。     

高效液相色谱法测定头孢泊肟酯含量的方法学研究

目的对头孢泊肟酯及其制剂含量的高效液相色谱检测法进行改进,并与紫外分光光度法作比较。方法以ODS-C18为固定相,甲醇-水(50∶50)为流动相,流速为1.5 mL.min-1,柱温为40℃,检测波长235 nm。结果头孢泊肟酯的浓度在25~150μg.mL-1内线性关系良好,回归方程为:A=7.457C-1.1287,r=0.999 9(n=7),测定头孢泊肟酯胶囊含量重复性良好,RSD为1%(n=9)。头孢泊肟酯胶囊的平均回收率为98.56%,平均含量为101.54%。结论本法简便、快速、准确、灵敏,可用于头孢泊肟酯及其制剂的含量测定。     

HPLC法测定头孢特仑新戊酯片的含量

目的:建立头孢特仑新戊酯片含量测定的高效液相色谱方法.方法:采用岛津CLASS VP C18(250 mm×4.6 mm,5 μm)色谱柱;以乙腈:醋酸钠缓冲液(35∶65)为流动相;以对羟基苯甲酸甲酯为内标;检测波长 254 nm;调整流量使头孢特仑新戊酯峰的保留时间为 14 min.结果:头孢特仑新戊酯的线性范围为100～1000 μg·mL-1,r＝0.9999,平均回收率为99.63%,RSD为0.57%.结论:本法可用于头孢特仑新戊酯片的含量测定,操作简便,结果准确.     

HPLC法测定头孢泊肟酯分散片中有关物质的含量

目的:建立测定头孢泊肟酯分散片中有关物质含量的方法。方法:采用高效液相色谱法。色谱柱为ODS(C18)柱,流动相为水-甲醇(55:45),流速为2.0mL·min-1,检测波长为240nm,柱温为25℃,进样量为20μL。结果:头孢泊肟酯A、头孢泊肟酯B与杂质能完全分离;头孢泊肟酯A最小检测限为1.6ng,头孢泊肟酯B最小检测限为1.2ng,其有关物质含量均<4.0%。结论:该方法简便、准确,灵敏度高,专属性强,可用于头孢泊肟酯分散片有关物质含量的测定。     

HPLC法测定阿德福韦酯片的含量和有关物质

目的建立高效液相色谱法测定阿德福韦酯片的含量和有关物质。方法采用Hypersil C18色谱柱,以乙腈-水(45∶55)(用磷酸调pH=4.0)为流动相,检测波长为261nm,流速为1.0mL·min-1。结果阿德福韦酯质量浓度在1.036⁶2.161μg·mL-1范围内线性关系良好(r=0.999 8),最低检测限为0.24ng,回收率为100.6%。结论该方法准确,灵敏,精密度高,专属性强,可用于阿德福韦酯片的含量测定和有关物质检查。     

RP-HPLC法测定盐酸头孢替安酯的含量及有关物质

目的建立反相高效液相色谱法测定盐酸头孢替安酯的含量和有关物质。方法采用InertsilODS—SPC18色谱柱（150mm×4．6mm,5μm）,以0．05mol／L磷酸二氢钾溶液-乙腈-冰醋酸（72：28：1）为含量测定的流动相;检测波长为254nm;柱温为35℃。结果盐酸头孢替安酯含量测定浓度在0．5μg／mL~500μg／mL范围内线性关系好,线性方程为A=20209C＋7646．7,相关系数r=0．9999,定量限为1．0ng,最低检测限为0．5ng。采用所建立的有关物质检查方法,盐酸头孢替安酯主峰能与相邻的杂质峰基线分离。结论该法简便、准确、灵敏度高,专属性强,可用于盐酸头孢替安酯含量测定和有关物质检查。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.