HPLC法测定青霉素V钾片的含量

目的：用高效液相色谱法测定青霉素V钾片的含量。方法：采用C18柱，以水-乙腈-冰醋酸（325：175：3.5）为流动相，检测波长为254nm。结果：线性范围为0.9934-3.9736mg/mL，r=0.9999；平均加样回收率为99.2％，RSD=0.57%。结论：HPLC法简便、准确，可用于青霉素V钾片的含量测定。     

高效液相色谱法测定青霉素V钾片中主药的含量

目的:建立以高效液相色谱法测定青霉素V钾片中主药含量的方法。方法:色谱柱为DiamonsilC18,流动相为乙腈-0.02mol/L醋酸钠(70∶30),流速为1.0ml/min,检测波长为268nm,灵敏度为0.01AUFS,柱温为(26±1)℃,进样量为20μl。结果:青霉素V钾检测浓度在10.0～120.0μg/ml范围内与峰面积呈良好的线性关系(r=0.9999,n=5);平均加样回收率为100.2%(RSD=0.42%)。结论:本方法快速、简便、准确,可用于青霉素V钾片的质量控制。     

浅谈青霉素V钾片含量测定色谱条件的改进

目的修订青霉素V钾片鉴别和含量测定方法的色谱条件。方法以VP-ODS柱为分析柱,pH值6.5的磷酸盐缓冲液-乙腈(70∶30)为流动相,在268nm波长的条件下分离测定青霉素V钾,并对方法进行了验证。结果青霉素V钾与杂质完全分离,在10μg~40μg范围内线性关系良好,r=0.9998。结论该色谱条件可用于青霉素V钾片的鉴别和含量测定,方法准确、简便、快捷。     

青霉素V钾及其有关物质分析方法的比较

目的：中国药典2005年版（ChP 2005）中青霉素V钾有关物质分析方法与其他药典及文献报道方法在流动相、检测波长、杂质限度等方面存在较大差异，本文比较了几种典型的青霉素V钾有关物质分析方法，为完善中国药典中青霉素V钾有关物质控制方法提供科学依据。方法：采用SinoChrom ODS—BP柱（150mm×4．6mm，5μm），柱温35℃，以青霉素V钾及其杂质的分离情况为指标，比较了ChP 2005方法和文献报道方法[流动相组成同欧洲药典5．1版方法，但采用等度洗脱]的专属性；由于在pH3．5时，醋酸盐缓冲系统的缓冲能力优于磷酸盐缓冲系统，故考察了将文献报道方法中pH3．5磷酸盐缓冲液换为pH3．5醋酸盐缓冲液后系统的专属性变化；比较了青霉素V钾及其有关物质的UV图谱，为检测波长的合理选择提供依据。结果：文献报道方法的专属性优于ChP 2005方法，能将青霉素V钾及其有关物质较好地分离；将pH3．5磷酸盐缓冲液换为pH3．5醋酸盐缓冲液后，方法的专属性无明显改变；除青霉素外，青霉素V及其杂质的uV吸收值均为：A（254nm）〈A（268nm）〈A（220nm），但考虑到220nm接近UV末端检测，容易受到试剂等因素的影响，故建议青霉素V钾有关物质控制采用268nm检测。结论：基于本文结果，为完善ChP 2005中青霉素V钾质量标准，建议：（1）将青霉素V钾原料及制剂中有关物质检查方法中的流动相改为专属性更好的文献方法流动相或者改进后的流动相，检测波长仍采用原方法的268nm检测；（2）为促进青霉素V钾原料及制剂产品质量的提高，建议有关物质检查项中增加单一杂质的限度，采用外标法或者校正因子法控制单一杂质。     

加校正因子的主成分自身对照法测定青霉素V钾片有关物质

目的：建立加校正因子的主成分自身对照法测定青霉素V钾片有关物质的含量。方法：采用XBridge Shield RP-18色谱柱（4.6mm×250mm，5μm），以磷酸盐缓冲液（pH3.5）-甲醇-水为流动相，梯度洗脱；检测波长268nm；测定特定杂质4-羟基苯氧甲基青霉素相对于青霉素V的校正因子，并进行定量分析。结果：4-羟基苯氧甲基青霉素杂质的相对保留时间为0.42，校正因子为1.41；加校正因子的主成分自身对照法与外标法测定的结果无显著性差异。结论：该方法简便快速，可准确测定青霉素V钾片中特定杂质的含量。     

HPLC法测定青霉素V钾分散片的含量

目的建立青霉素V钾分散片含量的HPLC测定方法.方法色谱柱:Hypersil BDS-C18(4.6 mm×200mm,5μm),流动相为水-乙腈-冰醋酸(65∶35∶1),检测波长为268nm.结果青霉素V进样量在10μg~50μg的范围内与峰面积呈良好的线性关系(r=0.9998).平均回收率为99.7%,RSD=0.70%.结论该方法简便,快速,重复性好.     

HPLC法测定青霉素V钾片的含量

目的:采用HPLC法测定青霉素V钾片的含量。方法:应用AlltechC18柱(150mm×4.6mm,ID),以水-甲醇(30∶70)为流动相,检测波长268nm。结果:青霉素V钾浓度在0.10～2.50mg·ml-1范围内,峰面积与进样量呈良好线形关系,相关系数r=0.9998,回收率为100.1%,RSD1.53%。结论:本方法准确、简便、专属性好,可作为该制剂的含量测定方法。     

青霉素Ⅴ钾分散片的研制

目的：筛选青霉素V钾分散片的处方,建立青霉素V钾分散片的含量测定方法。方法：采用均匀设计法筛选处方;紫外分析法测定含量。结果：青霉素V钾分散片崩解时限45－90s,T501.09min,Td2.07min;紫外测定回收率97.54%。结论：按本文处方生产的青霉素V钾分散片质量符合贡国药典对分散片的要求;紫外方法快速、简便,准确度较高。     

青霉素V钾片含量测定方法的比较

目的建立更简便的HPLC测定青霉素Ⅴ钾片的含量. 方法采用C18柱,以水-乙腈-醋酸(65∶35∶1.6)为流动相,检测波长254 nm.结果青霉素Ⅴ钾的浓度在1.5～3.5 g*L-1浓度范围内线性关系良好,r=0.9999,平均回收率99.9%,RSD=0.7%(n=5).结论HPLC测定青霉素Ⅴ钾的含量,重现性好,专属性强.     

对《中国药典》青霉素V钾片含量测定方法中流动相的改进

目的：改进青霉素V钾片含量测定的方法。方法：色谱条件：Inertis ODS－SP C18柱（150mm×4．6mm,5μm）;流动相为A-B（60：40）[A：pH3．5磷酸盐缓冲液（取0．5m01·L^-1磷酸二氢钾溶液,用磷酸调节pH至3．5）－乙腈．水（10：30：60）;B：pH3．5磷酸盐缓冲液．乙腈－水（10：55：35）];流速为1．0ml·min^-1;检测波长268nm;柱温：室温;进样量：10tzl。结果：青霉素V钾在0．0329—0．8216mg·ml“范围内呈良好线性关系（r=0．9999）;平均回收率99．9％,RSD为0．6％（n=9）。结论：此法重复性好,结果准确,可用于青霉素V钾、青霉素V钾片及胶囊的含量测定。     

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.