奈韦拉平纳米混悬液的制备及大鼠体内药动学研究

目的：：制备奈韦拉平纳米混悬剂,考察其在大鼠口服给药后体内的药动学特征。方法：采用高压均质法制备奈韦拉平纳米混悬剂,以纳米混悬剂粒径分布、PdI和Zeta电位为指标,考察了奈韦拉平纳米混悬剂的影响因素,并对制得的纳米粒进行表征;采用高效液相色谱法测定大鼠血浆中的奈韦拉平浓度,使用3P97软件计算相应的药动学参数。结果：奈韦拉平纳米混悬液平均粒径为(456.1±72.1) nm,PdI为(0.441±0.072),Zeta电位为(-24.4±4.7) mV。奈韦拉平混悬液和奈韦拉平纳米混悬剂在大鼠体内的AUC0-12分别为(7.57±0.52)和(11.72±1.83) mg·h·L-1;t1/2分别为(2.45±0.31)和(3.16±0.39) h;Tmax分别为(1.43±0.38)和(1.61±0.32) h;Cmax分别为(1.62±0.42)和(3.15±0.52) mg·L-1。结论：奈韦拉平纳米混悬液能够明显改善大鼠体内奈韦拉平的药动学行为,与奈韦拉平混悬液相比显著提高了药物的生物利用度。     

奈韦拉平2种片剂的人体生物等效性比较

目的:评价奈韦拉平国产片与进口片之间的人体生物等效性。方法:20名健康男性受试者,随机分为2组,分别于早晨空腹一次口服国产片或进口片200mg。1wk后再交叉服药。用HPLC法,以水∶甲醇=55∶45为流动相,蛋白沉淀后直接测定奈韦拉平血药浓度。结果:奈韦拉平国产片与进口片的主要药动学参数:tmax为(3.95±s0.22)h和(4.0±0.5)h,cmax为(13.8±1.9)mg·L-1和(14.0±2.1)mg·L-1,t1/2为(46±7)h和(42±8)h,AUC0～168为(765±198)mg·h·L-1和(779±132)mg·h·L-1,AUC0～∞为(839±230)mg·h·L-1和(840±150)mg·h·L-1。奈韦拉平国产片平均相对生物利用度为(97±14)%。结论:奈韦拉平国产片与进口片具有生物等效性。     

奈韦拉平片在健康人体的药代动力学和生物等效性

目的 研究2种国产奈韦拉平片(抗病毒药)在健康人体内的药代动力学,并评价这2种制剂的生物等效性.方法 20例健康成年男性受试者随机分组,按自身对照单次口服奈韦拉平片200 mg后,采用HPLC法测定奈韦拉平的血浆浓度,非房室模型法计算各主要药代动力学参数,并进行方差分析和生物等效性评价.结果 参比制剂与受试制剂奈韦拉平的tmax分别为(3.5±2.1)、(3.0±1.9)h;Cmax分别为(2.6.±0.5)、(2.6±0.5)mg·L-1;t1/2分别为(57.6±10.4)、(58.6±10.2)h;MRT分别为(55.6±6.5)、(56.8±5.0)h;AUC0-t分别为(167.6±36.1)、(171.8±32.7)mg·L-1·h;AUC0→∞分别为(169.9±36.6)、(174.2±33.1)mg·L-1·h;CL/F分别为(1.2±0.3)、(1.2±0.2)L·h-1;Vd/F分别为(100.3±20.4)、(99.4±20.8)L;受试制剂相对于参比制剂的生物利用度为(103.7±11.6)%.结论 受试制剂与参比制剂具有生物等效性.     

国产奈韦拉平片的血药浓度测定及相对生物利用度研究

目的建立奈韦拉平血药浓度的HPLC测定法,用于人体生物等效性研究。方法采用随机双交叉实验设计,20名健康受试者口服受试制剂和参比制剂200 mg,用HPLC法测定血浆中的奈韦拉平浓度。结果受试制剂和参比制剂的AUC0-168分别为(155.66±22.41)、(150.66±22.11)mg.h.L-1;AUC0-∞分别为(163.30±22.88)、(157.75±22.87)mg.h.L-1;Cmax分别为(2.52±0.31)和(2.60±0.48)mg.L-1;tmax分别为(3.1±0.7)和(3.0±0.7)h;t1/2分别为(38.12±2.23)、(36.79±5.06)h。受试制剂的相对生物利用度为103.6%±8.6%。结论经统计学分析,国产奈韦拉平片剂与进口奈韦拉平片剂具有生物等效性。     

奈韦拉平胶囊的人体生物等效性研究

目的:研究国产奈韦拉平胶囊与进口奈韦拉平片的生物等效性。方法:24名健康男性志愿者随机交叉单剂量口服受试制剂(国产奈韦拉平胶囊)或参比制剂(进口奈韦拉平片),采用高效液相色谱法测定血药浓度,计算药动学参数和相对生物利用度。结果:受试制剂与参比制剂的Cmax分别为(2.516±0.446)、(2.798±0.394)μg/ml;tmax分别为(7.5±10.7)、(3.6±2.1)h,t1/2分别为(51.4±25.3)、(46.4±9.8)h;AUC0～168分别为(160.540±38.007)、(167.459±30.629)(μg·h)/ml;AUC0～∞分别为(180.064±51.005)、(183.052±36.828)(μg·h)/ml;受试制剂的相对生物利用度为(98.368±22.99)%。结论:受试制剂与参比制剂具有生物等效性。     

西洛他唑片在人体的药动学研究

目的研究西洛他唑片在人体内的药动学。方法12名健康男性志愿者单剂量口服100 mg西洛他唑片,采用高效液相色谱法测定血浆中西洛他唑浓度,数据用3P97软件统计处理。结果西洛他唑片药-时曲线符合二室模型,其Cm ax为(769.5±228.2)μg.L-1,Tm ax为(3.004±1.204)h,T1/2α为(4.72±3.38)h,T1/2β为(25.95±12.22)h,AUC0-72为(12525±3077)μg.h.L-1,AUC0-为(13003±3206)μg.h.L-1。结论西洛他唑在人体内药动学过程符合二室开放模型,本研究可为临床用药提供药动学参数。     

西洛他唑片在人体的药动学研究

目的研究西洛他唑片在人体内的药动学.方法 12名健康男性志愿者单剂量口服100 mg西洛他唑片,采用高效液相色谱法测定血浆中西洛他唑浓度,数据用3P97软件统计处理.结果西洛他唑片药-时曲线符合二室模型,其Cmax为(769.5±228.2)μg·L-1,Tmax为(3.004±1.204)h,T1/2α为(4.72±3.38)h, T1/2β为(25.95±12.22)h,AUC0-72为(12525±3077)μg·h·L-1,AUC0-为(13003±3206) μg·h·L-1.结论西洛他唑在人体内药动学过程符合二室开放模型,本研究可为临床用药提供药动学参数.     

盐酸伐昔洛韦片的药动学及相对生物利用度

目的:研究盐酸伐昔洛韦片在健康人体的药动学和相对生物利用度。方法:采用两制剂双周期交叉对照的研究方法,以HPLC法测定18例健康志愿者单剂量口服盐酸伐昔洛韦片600mg后血浆中阿昔洛韦的浓度变化,采用DAS2.0软件计算药动学参数。结果:阿昔洛韦的线性范围为0.201～12.884mg.L-1(r=0.9999),日内和日间RSD均小于6.0%。供试制剂与参比制剂的主要药动学参数tmax分别为(1.5±0.6)h和(1.9±0.7)h;Cmax分别为(2.7±0.5)mg.L-1和(2.8±0.7)mg.L-1;t1/2分别为(3.0±0.6)h和(3.3±0.9)h;AUC0-t分别为(10.6±1.9).和(10.6±2.4)mg.L-1.h;AUC0-∞分别为(11.5±2.0)mg.L-1.h-1和(11.7±2.6)mg.L-1.h。两种盐酸伐昔洛韦片主要药动学参数间差异均无显著性(P>0.05)。供试制剂对参比制剂的相对生物利用度为(101.9±14.9)%。结论:供试制剂和参比制剂具有生物等效性。     

甲芬那酸分散片在健康人体的生物等效性评价

目的:研究甲芬那酸分散片和普通片在健康人体的药动学特征和生物等效性.方法:采用标准两周期交叉设计自身对照试验方法,18名健康志愿者单剂量口服500 mg甲芬那酸分散片或普通片,用反相高效液相色谱法(RP-HPLC)测定血清中甲芬那酸的浓度,计算其药动学参数并评价两种制剂的生物等效性.结果:甲芬那酸分散片和普通片的主要药动学参数Tmax(实测值)分别为(1.1±0.6)h和(2.1±0.8)h,Cmax(实测值)分别为(5.8±2.2)mg·L-1和(5.9±3.0)mg·L-1,AUC(0-14 h)分别为(18.1±3.4)mg·L-1·h和(17.3±5.0)mg·L-1·h,AUC(0-inf)分别为(18.7±3.3)mg·L-1·h和(18.0±4.9)mg·L-1·h,T1/2Ke分别为(2.0±0.8)h和(2.3±1.2)h.除Tmax外,甲芬那酸分散片和普通片各主要药动学参数间差异无显著性(P＞0.05);甲芬那酸分散片对普通片的相对生物利用度为(111.3±31.9)%.结论:健康人单剂量口服500mg甲芬那酸分散片与普通片具有生物等效性.     

复方苯磺酸氨氯地平/阿托伐他汀钙片的人体药动学

目的:研究复方苯磺酸氨氯地平/阿托伐他汀钙片中氨氯地平和阿托伐他汀钙在健康人体的药动学特征.方法:30名健康志愿者随机分成3组,每组10名(男女各半),分别单次空腹口服不同规格的受试药品复方苯磺酸氨氯地平/阿托伐他汀钙片,规格分别为5 mg/10 mg/片,10 mg/10 mg/片,5 mg/20 mg/片各1片,采用液相色谱串联质谱方法(LC-MS/MS)研究2种成分的血药浓度经时过程,计算相应的药动学参数,并评价复方苯磺酸氨氯地平/阿托伐他汀钙片在人体的药动学特征.结果:氨氯地平5 mg/10 mg/片/剂量组中的药动学参数分别为Cmax为(3.1±0.5)μg·L-1,AUC0-120为(131±22)μg·h·L-1;10 mg/10 mg/片剂量组,Cmax＜为(6.8±1.2)μg·L-1,AUC0-120为(327±110)μg·h·L-1;5 mg/20 mg/片/剂量组,Cmax为(3.1±0.5)μg·L-1,AUG0-120为(130±16)μg·h·L-1.阿托伐他汀5 mg/10 mg/片剂量组中的药动学参数分别为Cmax为(11.3±6.7)μg·L-1,AUC0-120为(133.8±93.3)μg·h·L-1;10 mg/10 mg/片剂量组,Cmax为(16.7±12.1)/μg·L-1,AUC0-120为(107.7±60.4)μg·h·L-1;5 mg/20 mg/片剂量组,Cmax为(15.0±9.4)μg·L-1,AUC0-120为(147.3±59.3)μg·h·L-1.结论:复方苯磺酸氨氯地平/阿托伐他汀钙片中氨氯地平的Cmax;AUC0-120,AUC0-∞与剂量呈线性;阿托伐他汀的cMAX,AUC0-120,AUC,0-∞与剂量呈非线性药动学特征.     

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.