HPLC法测定瑞格列奈二甲双胍片中二甲双胍的5种有关物质

目的建立复方制剂瑞格列奈二甲双胍片中二甲双胍有关物质的检查方法。方法采用HPLC法,色谱柱为CAPCELL PAK SCX(150 mm×4.6 mm,5.0μm);以0.35 mol·L-1磷酸二氢铵水溶液(用磷酸调节pH至3.0)为流动相进行等度洗脱,流速为1.0 m L·min-1;采用紫外检测器,波长为210 nm。结果二甲双胍与有关物质A、B、C、D、E均能有效分离,分离度均大于1.5,且瑞格列奈不干扰有关物质的测定。结论该方法适用于该复方制剂中二甲双胍的有关物质控制。     

HPLC法测定二甲双胍格列本脲片(Ⅰ)中盐酸二甲双胍的含量

目的用高效液相色谱法测定二甲双胍格列本脲片(Ⅰ)中盐酸二甲双胍的含量。方法采用依利特C18色谱柱(4.6 mm×250 mm,5μm),流动相为0.01 mol.L-1磷酸二氢钾溶液(用磷酸调pH至3.0)-甲醇(35∶65),流速为1.0 mL.min-1,柱温为室温,检测波长为233 nm。结果盐酸二甲双胍浓度在5.95～119μg.mL-1范围内线性关系良好,r=0.999 8;平均回收率为99.48%,RSD=0.6%(n=6)。结论该法简便、快速、准确、专属性强,可作为二甲双胍格列本脲片(Ⅰ)中盐酸二甲双胍的含量测定。     

二甲双胍格列吡嗪片中盐酸二甲双胍含量测定方法改进

目的建立高效液相法测定二甲双胍格列吡嗪片中盐酸二甲双胍含量测定方法。方法采用C18(4.6mm×150 mm,5μm)色谱柱;以0.05%庚烷磺酸钠溶液(用10%磷酸溶液调节p H值至4.0)-乙腈(84∶16)为流动相,流速:1.0 m L·min-1,检测波长:233 nm,柱温:30℃。结果盐酸二甲双胍在10.02~30.06μg·m L-1浓度范围内与峰面积呈良好的线性关系(r=0.999 9),回收率为101.0%,RSD=0.66%(n=9)。结论所建立的方法较原国家注册标准专属性更强、更准确。     

二甲双胍与二甲双胍-牛磺酸复方制剂在Beagle犬体内的药物动力学考察

目的比较单组分二甲双胍与二甲双胍复方制剂的药物动力学差异,为复方制剂的组方及临床应用提供参考。方法Beagle犬口服给予盐酸二甲双胍胶囊(10 mg.kg-1)和二甲双胍-牛磺酸复方制剂胶囊(等同于盐酸二甲双胍10 mg.kg-1),RP-HPLC法测定其血药质量浓度,拟合药物动力学曲线,计算药物动力学主要参数。结果单一制剂与复方制剂的二甲双胍在Beagle犬体内药物动力学都符合二室模型,主要药物动力学参数为AUC0-t(10.29±3.54)、(10.12±2.81)mg.h.L-1,ρmax(2.11±0.46)、(1.73±0.49)mg.L-1,tmax(2.67±0.41)、(2.50±0.45)h。结论单一制剂与复方制剂给药的二甲双胍主要药物动力学参数采用双侧t检验,无显著性差异(P>0.05),提示二甲双胍-牛磺酸复方制剂具有药物动力学理论的可行性。     

高效液相色谱法测定复方二甲双胍格列本脲片中杂质双氰胺的含量

目的:建立以高效液相色谱法测定复方二甲双胍格列本脲片中杂质双氰胺含量的方法。方法:色谱柱为Maeherey-Nagel不锈钢柱,流动相为甲醇-1.7%磷酸二氢铵(30∶70),检测波长为218nm,流速为1.0ml/min,进样量为20μl,柱温为室温。结果:双氰胺检测浓度在0.0 625~1.000μg/ml范围内线性关系良好,平均加样回收率为96.53%(RSD=1.66%)。结论:本方法灵敏度高,结果准确、可靠,专属性强,操作简便、快速,适合于复方二甲双胍格列本脲片中杂质双氰胺的含量测定。     

复方制剂中二甲双胍、格列吡嗪和肉桂醛的HPLC法测定

建立了HPLC法同时测定复方二甲双胍格列吡嗪胶囊中二甲双胍、格列吡嗪和肉桂醛的含量。采用C18色谱柱,以甲醇-0.1%冰醋酸（60∶40,pH4.0）为流动相,检测波长254nm。二甲双胍、格列吡嗪和肉桂醛分别在0.4～2μg、0.01～0.05μg和0.032～0.16μg内线性关系良好;平均回收率分别为99.3%、99.9%和99.0%。     

液相色谱-串联质谱法测定人血浆中二甲双胍的浓度

目的:建立LC-MS/MS法测定人血浆中二甲双胍的浓度。方法:人血浆样本以乙腈沉淀蛋白后,选用Zorbax SB-C18Narrow-Bore色谱柱(150 mm×2.1 mm,5μm),以甲醇-10 mmol.L-1乙酸铵(含1%甲酸)(5:95)为流动相,流速为0.3 mL.min-1;选用API3200型三重四极杆串联质谱仪的多重反应监测(MRM)扫描方式进行监测,电喷雾离子化源,正离子方式,选择监测离子反应分别为m/z130.1→m/z71.0(二甲双胍)和m/z147.1→m/z58.2(内标米曲肼)。结果:二甲双胍和米曲肼的保留时间分别为1.27 min和1.26 min;血浆中二甲双胍的线性范围为0.010～3.000 mg.L-1(r>0.99),定量下限为0.010mg.L-1;日内、日间RSD均小于6%;相对偏差(RE)均在±6%的范围以内;平均提取回收率为(86.6±5.4)%;稳定性试验中,在各种贮存条件下血浆中二甲双胍均较稳定。结论:该方法快速、灵敏,专属性强,重现性好,适用于人血浆中二甲双胍浓度的测定,可应用于盐酸二甲双胍肠溶片的人体生物等效性研究。     

RP-HPLC法测定二甲双胍的血药浓度

目的建立反相高效液相色谱法测定血清中二甲双胍浓度的方法。方法含内标的血清经1.5mL乙腈沉淀,上清经3mL的三氯甲烷萃取浓缩后直接进样。色谱条件为:色谱柱:SymmetryC18;流动相¨乙腈-磷酸缓冲液(0.06M,pH7.3)(1¨3)[内含0.5mM的SDS;10mM的三乙胺(用0.1M的磷酸调pH为7.3)];检测波长;235nm。结果二甲双胍在0.05~1.6μg·mL-1范围内呈良好的线性关系,加权回归系数r=0.99991。日内变异系数4.90%,2.59%,1.03%,日间变异系数8.56%,4.62%,0.72%,方法的相对回收率在97.43~110.88%。结论该方法可用于二甲双胍血药浓度的测定。     

复方二甲双胍胶囊在健康受试者体内的药物动力学和相对生物利用度

目的 :研究复方二甲双胍胶囊在健康受试者体内的药物动力学和相对生物利用度。方法 :2 0名男性志愿者随机交叉口服复方二甲双胍胶囊 (试验药 )或合用二甲双胍片 格列本脲片 (参比药 ) ,HPLC 紫外法和LC MS法测定人血浆中二甲双胍和格列本脲浓度 ,计算药动学参数和相对生物利用度。结果 :口服试验药和参比药后二甲双胍的Cmax 分别为1.87± 0 .36和 1.77± 0 .35mg·L-1;Tmax为 1.7± 0 .6和 1.8± 0 .5h ;AUC0 -∞ 为 8.13± 1.32和 8.6 2±1.4 7mg·L-1·h-1,格列本脲的Cmax分别为 12 9.2±5 1.4和 12 3.9± 5 0 .7μg·L-1;Tmax 为 2 .3± 0 .7和2 .6± 0 .9h ;AUC0 -∞ 为 0 .6 90± 0 .2 2 8和 0 .6 32±0 .2 11mg·L-1·h-1,以上参数在试验药和参比药之间皆无显著性差异。试验片中二甲双胍和格列本脲相对于参比药的生物利用度分别为 95 .0 %±11.5 %和 10 9.6 %± 8.8%。结论 :复方二甲双胍胶囊中二甲双胍和格列本脲与参比药相比皆生物等效     

HPLC测定二甲双胍格列美脲胶囊中的格列美脲含量

目的：采用 HPLC方法测定二甲双胍格列美脲胶囊中格列美脲的含量。方法色谱柱采用 Diamonsil C18（200 mm ＆#215;4.6 mm,5μm）,流动相为0.05 mol/L甲酸铵缓冲液（pH 4）-乙腈（体积比为41∶63）,检测波长为228 nm,流速10 ml/min。结果格列美脲的平均回收率为99.4%（ RSD =1.0%, n =9）,线性范围为0.1~0.6 mg/L（r=0.9991, n=6）。结论采用 HPLC方法测定二甲双胍格列美脲胶囊中格列美脲的含量,方法简便、拥有较高准确性、专属性,且在测定过程中测量结果并不会受到盐酸二甲双胍的干扰,效果较好,可以应用到对该类复方制剂的质量控制过程中。     

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.