LC-MS/MS法测定人血浆中替米沙坦的浓度及其人体生物等效性研究

目的:建立以高效液相色谱串联质谱电喷雾(LC-MS/MS)法测定人血浆中替米沙坦浓度的方法,并考察2种替米沙坦片的生物等效性。方法:人血浆样本以乙腈沉淀蛋白后,选用Zorbax SB-C_(18) Narrow Bore色谱柱,以甲醇-10mmol.L~(-1)乙酸铵(含0.5%甲酸)(80∶20)为流动相,流速为0.4mL.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/z515.2→276.2(替米沙坦)和m/z748.5→m/z158.2(克拉霉素,内标)。结果:替米沙坦和克拉霉素的保留时间分别为1.51、1.25min。替米沙坦血药浓度在1.00～1500ng·mL~(-1)范围内线性关系良好(r=0.9985),定量下限为1.00ng·mL~(-1);日内、日间RSD均≤6%,相对偏差(RE)均在±7%的范围以内;平均提取回收率为(93.0±3.9)%。替米沙坦片受试制剂与参比制剂平均药动学参数分别为:t_(1/2)(25.5±12.5)、(26.5±11.8)h,t_(max)(1.50±0.78)、(1.59±1.16)h,c_(max)(358±212)、(389±298)ng·mL~(-1),AUC_(0～96h)(2383±1146)、(2411±1192)ng.h.mL~(-1)。替米沙坦片受试制剂的平均生物利用度为(101.3±22.6)%。结论:该方法高效、灵敏、专属性强;2种替米沙坦片等效。     

HPLC法测定人血浆中盐酸二甲双胍浓度

目的:建立血浆中盐酸二甲双胍浓度测定方法。方法:血浆在酸性条件下以乙腈沉淀蛋白后,用二氯甲烷萃取纯化,以乙腈-5 mmol·L~(-1)磷酸盐缓冲液(pH 4．8)(45:55,每100 mL流动相中含十二烷基硫酸钠0．17 g)为流动相,色谱柱为DIAMONSIL~(TM)C_(18)柱(250 mm×4．6 mm,5μm),检测波长为233 nm,柱温为40℃。流速为1．2 mL·min~(-1)。结果:在此色谱条件下,盐酸二甲双胍与血浆中其他成分分离完全,线性范围为60．06～4 004 ng·mL~(-1),最低检测浓度为60．06 ng·mL~(-1),相对回收率在101．3％～108．3％,日内精密度RSD＜5．4％,日间精密度RSD＜13％。结论:该法稳定、灵敏、可靠,可用于人体血浆中盐酸二甲双胍浓度的测定。     

HPLC-荧光检测法测定人血浆中替米沙坦的质量浓度及药代动力学研究

目的建立人血浆中替米沙坦质量浓度的HPLC-荧光检测法,测定健康受试者口服替米沙坦片后的血药浓度,并计算其药代动力学参数。方法18名男性健康受试者单剂量口服替米沙坦80mg,血浆经过简单处理,用荧光检测器RP-HPLC法测定。采用C18(250mm×4.6mm,5μm)色谱柱,流动相:0.1%醋酸铵-乙腈(40∶60),冰醋酸调pH6.5。流速1.0mL·min-1,荧光检测激发波长315nm,发射波长365nm。结果替米沙坦的线性范围为2.5~750ng·mL-1(r=0.9998),最低检测浓度为0.5ng·mL-1,达峰时间Tmax为(1.23±0.37)h;血药浓度峰值Cmax为(485.16±219.28)ng·mL-1;T1/2β为(17.24±3.91)h;药时曲线下面积AUC(0→48)为(2645.41±1069.74)ng·h·mL-1。结论该法简单、灵敏、准确,可用于替米沙坦的体内分析。     

高效液相色谱荧光检测法测定人血浆中替米沙坦浓度及其应用

目的:建立高效液相色谱荧光检测人血浆中替米沙坦浓度的方法,并用于研究替米沙坦片的人体药代动力学。方法:采用固相萃取方法提取血浆中的替米沙坦,色谱柱为 Diamonsil C_(18)柱(5μm,4.6mm×150mm),以乙腈-磷酸二氢钾缓冲液(61∶39,磷酸调 pH=3.74)为流动相,流速1.0mL·min~(-1),坎地沙坦为内标,荧光检测波长λ_(Ex)=305nm,λ_(Em)=365nm。结果:本法测定替米沙坦的线性范围为0.5-144ng·mL~(-1),r=0.9998,绝对回收率在79.62%-85.69%(n=5),相对回收率在101.9%-109.0%(n=5),日内和日间 RSD 分别为4.23%-9.80%和4.03%-9.95%(n:5)。结论:本法灵敏、准确,操作简捷,适用于替米沙坦的血药浓度测定及药代动力学研究。     

HPLC-荧光法测定人血浆中替米沙坦血药浓度的方法改进

目的:改进以高效液相色谱-荧光法测定人血浆中替米沙坦浓度的方法。方法:以萘普生为内标,采用乙酸乙酯提取的方法处理血浆。色谱柱为SymmetryC8,流动相为乙腈-0.01mol.L-1磷酸二氢钾溶液(47∶53),流速为1.0mL.min-1,荧光检测波长为305nm(激发波长)、365nm(发射波长),进样量为20μL。结果:替米沙坦检测浓度在2.5~200ng.mL-1范围内线性关系良好(r=0.9998)。最低检测限为1ng.mL-1。方法的提取回收率为(89.91±10.07)%,日内和日间RSD<10%。样品3次冻融及提取后在24h内稳定性良好。结论:本方法操作简便、灵敏度和精确度高、重现性好,适于替米沙坦的体内药物浓度测定和药动学研究。     

HPLC法测定人血浆中盐酸阿比朵尔浓度

目的:建立盐酸阿比朵尔血药浓度测定方法。方法:采用高效液相色谱紫外检测法测定盐酸阿比朵尔的血药浓度,检测波长315 nm。血样加入乙腈沉淀;色谱柱:Alltech Apollo C_(18)(250 mm×4．6 mm,5μm);流动相A为0．1%三乙胺水溶液(加磷酸调pH值至2．0),流动相B为乙腈。梯度洗脱程序:A与B的体积比变化为52．5: 47．5(0～5．5 min),52．5:47．5～10:90(5．5～6．5 min),10:90～0:100(6．5～6．6 min),0:100(6．6～8 min),0:100～52．5:47．5(8～8．5 min)。流速:1．0 mL·min~(-1)。结果:在此条件下,盐酸阿比朵尔与血浆中其他成分分离完全,线性范围为5～1280 ng·mL~(-1),最低检测浓度为5 ng·mL~(-1),相对回收率为93．6%～99．0%,日内日间精密度RSD为0．5%～3．6%。结论:高效液相色谱紫外法稳定、灵敏、可靠,可用于人体血浆中盐酸阿比朵尔浓度的测定。     

高效液相色谱法测定人血浆中阿立哌唑浓度

目的:建立以高效液相色谱法测定人血浆中阿立哌唑浓度的方法。方法:血浆样品经液-液提取后,采用高效液相色谱法检测。色谱柱为C18,流动相为0．03mol·L-1醋酸铵-乙腈(34:66),流速为0．8mL·min-1,柱温为40℃,检测波长为257nm,灵敏度为0．01 AUFS。结果:阿立哌唑检测浓度线性范围为5．0～600．0ng·mL-1(r=0．999 5),提取回收率均大于90％。结论:该方法灵敏、准确、快速,适用于人血浆中阿立哌唑浓度的检测。     

RP-HPLC法研究塔斯品碱在大鼠体内的药代动力学

目的:建立大鼠血浆中塔斯品碱浓度的 RP-HPLC 分析方法,并研究其药代动力学特性。方法:用液液萃取技术对血浆中的塔斯品碱进行纯化、浓集,用 RP-HPLC 法进行测定。色谱柱:Kromsil C_(18)ODS 柱(150mm×4.6mm,5μm);流动相:甲醇-60 mmol·L~(-1)磷酸二氢钠-20 mmol·L~(-1)SDS(70:30);流速:1.0 mL(min~(-1);检测波长:245nm;柱温:室温。结果:方法线性范围为15.63～903.7 ng·mL~(-1)(r=0.994 0),日内、日间精密度的 RSD 分别为3.8%～4.9%和4.2%～7.6%,平均回收率为(107.33±7.3)%～(97.30±4.8)%。塔斯品碱在大鼠体内的达峰时间约2.84 h,平均峰浓度为64.15 ng·mL~(-1),药时曲线下面积为1214.98 ng·mL~(-1)·h,消除半衰期为10.96 h。结论:分析方法灵敏、准确,适合于塔斯品碱的药代动力学研究。塔斯品碱经大鼠口服吸收较慢,而消除很慢。     

高效液相色谱法测定人血浆中替米沙坦的浓度

目的:建立HPLC法测定人血浆中替米沙坦浓度。方法:采用Dimak Diamonsil钻石C18色谱柱(200 mm×4．6 mm,5μm);流动相,水-三乙胺-乙腈(73:0．12:27);荧光检测激发波长为305 nm,发射波长为380 nm。结果:替米沙坦线性范围为1 -200 ng·ml-1,最低检测限为0．25 ng·ml-1。结论:该法准确、灵敏、简便。     

高效液相色谱法测定大鼠血浆中雷替曲塞浓度

目的:建立测定大鼠血浆中雷替曲塞的高效液相色谱方法。方法:血浆经甲醇沉淀蛋白后离心,上清液直接进样,HPLC- 紫外检测。色谱条件:Phenomenex Prodigy 5μODS3 100A色谱柱(5μm,0．46cm×25 cm)和Shim-pack GVP-ODS预柱。流动相为1％醋酸-甲醇-乙腈(60:25:15),流速1 mL·min-1。检测波长349 nm。结果:本法线性范围为25- 5000 ng·mL-1,最低定量限为25 ng·mL-1。血浆中雷替曲塞的绝对回收率为95．1％-105．8％,方法回收率为102．3％- 107．7％,日内RSD≤9．0％,日间RSD≤8．3％。结论:本方法适用于雷替曲塞在大鼠体内的药代动力学研究。     

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.