阿普洛韦片在人体内的相对生物利用度和生物等效性

目的;比较两种阿昔洛韦片剂的相对生物利用度及生物等效性.方法:8例男性健康受试者自身交叉对照、草剂量Po阿昔洛韦受试片或参比片各400mg.采用HPLC法测定血浆阿昔洛韦浓度、单室模型拟合药物动力学参数,数据经对数转换后进行双单侧检验评价生物等效性.结果:阿昔洛韦受试片和参比片的t_max、c_max、AUC相比较,P均>0.05,阿昔洛韦受试片的相对生物利用度为(104.49土18.06)%.结论:阿昔洛韦受试片和参比片生物等效.     

氟康唑在健康人体的药物动力学和生物等效性

目的 研究氟康唑(抗真菌药)在健康人体的药物动力学及生物等效性.方法 20名健康志愿者随机双交叉、单剂量口服受试制剂和参比制剂150 mg,用高效液相色谱-串联质谱联法测定人血浆中氟康唑的浓度.使用DAS软件拟合计算药物动力学参数和相对生物利用度,评价两制剂的生物等效性.结果 受试制剂和参比制剂药物动力学参数:Cmax分别为(3.26±0.54),(3.17±0.41)μg·mL-1;tmax分别为(1.42±0.65),(1.62±0.75)h;t1/2分别为(29.75±4.89),(30.34±4.67)h;AUC0-120h分别为(131.4 ±23.4),(135.2±20.6)μg·mL-1·h;AUC0-∞分别为(140.5±26.3),(145.0±23.6)μg·mL-1·h.受试制剂相对于参比制剂的生物利用度为(97.2±7.6)%.结论 2种制剂具有生物等效性.     

国产酮咯酸氨丁三醇分散片的人体相对生物利用度研究

目的评价酮咯酸氨丁三醇分散片剂的人体相对生物利用度,并与胶囊剂比较其生物等效性。方法 18名男性健康受试者随机、自身对照交叉单剂量口服酮咯酸氨丁三醇分散片和胶囊,采用RP-HPLC法测定血浆中酮咯酸氨丁三醇的浓度。结果单剂量口服含酮咯酸氨丁三醇20 mg的受试和参比制剂,其达峰时间Tmax分别为(0.68±0.30)、(0.80±0.38)h;血药浓度峰值Cmax分别为(3 124.44±382.96)、(3 170.28±289.03)ng/mL;药时曲线下面积AUC(0→24)分别为(13 939.32±2 471.53)、(14 312.29±2 268.26)ng.h/mL。两种制剂的药物动力学参数比较差异无统计学意义(P>0.05),受试制剂的相对生物利用度(F)为97.86%±11.62%。结论两种制剂具有生物等效性。     

双氯芬酸钠缓释片的人体生物等效性考察

目的研究双氯芬酸钠缓释片在健康人体内的药物动力学及其相对生物利用度。方法20名健康男性受试者随机分为2组,根据交叉试验设计方案,单次给予和多次给予两种双氯芬酸钠缓释制剂,采用HPLC法测定其血药浓度,并计算药物动力学参数。结果口服单次给药的药物动力学参数计算结果显示,血浆中受试制剂和参比制剂的AUC0-t分别为(2 103.0±651.7)和(2 264.5±731.9)μg.h.L-1,以AUC0-t计算,受试制剂的相对生物利用度为(95.4±21.8)%。口服多次给药的药物动力学参数计算结果显示,血浆中受试制剂和参比制剂的AUCss分别为(2 922.5±398.6)和(2 843.6±429.4)μg.h.L-1,受试制剂的DF/τ为参比制剂的(102.8±18.0)%,以AUCss计算,受试制剂的相对生物利用度为(103.5±10.3)%。结论统计学分析结果表明受试制剂和参比制剂具有生物等效性。     

高效液相色谱荧光检测法考察阿昔洛韦片人体生物等效性

目的:10名健康志愿者随机交叉给药,分别单次po 400mg国产阿昔洛韦被试片剂和参比片剂进行人体生物等效性研究.方法:采用高效液相色谱荧光检测法,测定血浆中阿昔洛韦浓度.结果:经3p97药物动力学计算程序处理拟合,符合口服给药-室开放模型,被试片剂与参比片剂的主要药物动力学参数分别为:l_(max)(1.14±0.28)和(1.25±0.37)h,C_(max)(1078.37±192.32)和(108.93±203.31)μg/L,AUC_(o→∞)(4728.07±940.87)和(5012.86±1295.92)μg·h/L,由梯形法计算AUC_(0→t)分别为(4572.14±917.72)和(4780.74±1197.04)μg·h/L,由AUC_(0→(?))计算所得的相对生物利用度为(97.0±10.5)%.主要药物动力学参数经方差分析和双单侧检验两种片剂无显著性差别(P>0.05).结论:两者为生物等效制剂.     

阿昔洛韦药代动力学及相对生物利用度研究

目的对阿昔洛韦药代动力学及相对生物利用度进行研究.方法用HPLC法研究10名健康男性受试者口服400mg供试制剂阿昔洛韦(无环鸟苷片)和400mg参比制剂阿昔洛韦(甘泰片)后,研究血浆中阿昔洛韦浓度及药代动力学指标,并对阿昔洛韦(无环鸟苷片)生物利用及生物等效性进行评价.结果受试者口服阿昔洛韦(甘泰片)后tmax为(1.2±0.5)h,Cmax(906.71±188.95)ng·ml-1,t1/2为(2.59±0.53)h.口服阿昔洛韦(无环鸟苷片)后,tmax为(1.8±0.5)h,Cmax为(847.72±180.32)ng·ml-1,t1/2为(2.41±0.58)h.方差分析表明两种制剂药代动力学参数AUC0-∞、AUC0-r以及Cmax生物等效.结论两种制剂的吸收程度相同,生物利用度符合要求.     

克拉霉素片剂的人体药动学及生物等效性LC-MS-MS法研究

目的 建立LC-MS-MS法测定人血浆中克拉霉素的浓度,研究克拉霉素片剂的人体药动学和生物等效性.方法 24名健康受试者单剂量交叉口服受试制剂和参比制剂500mg,采用LC-MS-MS法测定血浆中不同时间点克拉霉素的药物浓度,计算主要药代动力学参数及相对生物利用度,评价两种制剂的生物等效性.结果 受试制剂和参比制剂的主...     

重组人生长激素在健康猕猴体内的比较药代动力学

目的:比较两种国产重组人生长激素在健康猕猴体内的药代动力学,评价两种药物的相似性。方法:采用交叉自身比较设计,8只健康成年猕猴分别单次皮下注射受试品和参比品0.35 IU·kg-1;采用酶联免疫吸附分析法检测血清中药物浓度,统计矩方法计算各主要药代动力学参数;采用3P97软件参考生物等效性标准对参数进行评价。结果:方法的特异性、灵敏度、精密度和准确度均符合药代动力学研究要求。受试品与参比品的血药浓度-时间曲线基本一致,主要药代动力学参数AUC0～12 h分别为(512±102)和(476±71)μg·h·L-1;AUC0～∞分别为(538±115)和(494±77)μg·h·L-1;Cmax分别为(108±18)和(96±23)μg·L-1;t1/2分别为(2.8±0.7)和(2.2±0.7)h;MRT分别为(4.2±0.8)和(4.0±0.8)h;CLs/Fsc分别为(0.047±0.014)和(0.060±0.013)L·h-1·kg-1;Vd/Fsc分别为(0.194±0.04)和(0.24±0.06)L·kg-1。以AUC0～∞计算,受试品与参比品比较,相对生物利用度F为(109±15)%。受试品相对于参比品的生物等效性用AUC0～12 h,AUC0～∞和Cmax的90%可信区间评价分别为89.2%～114.3%8,7.4%～112.7%和98.5%～124.4%,均符合生物等效性判断标准。结论:受试品与参比品药代动力学参数评价结果满足生物等效接受标准;两种重组人生长激素在猕猴体内呈现相同的药代动力学特征。     

人血浆中阿昔洛韦的HPLC-MS法的建立及盐酸伐昔洛韦片的生物等效性研究

目的:建立人血浆中盐酸伐昔洛韦在人体内代谢产物阿昔洛韦的HPLC-MS分析方法,分析临床用药每人0.3 g盐酸伐昔洛韦片时,阿昔洛韦在人体内的药动学过程和特征,评价受试制剂和参比制剂的生物等效性.方法:采用双交叉随机实验设计:20名健康男性受试者随机交叉口服两种盐酸伐昔洛韦片0.3 g后,采用HPLC-MS法测定人血浆中阿昔洛韦浓度,计算药代动力学参数.结果:20名健康男性受试者口服受试制剂和参比制剂0.3 g后,估算的阿昔洛韦的消除半衰期分别为3.07±0.31 h和3.05±0.25 h,达峰时间分别为0.9±0.2 h和1.0±0.2 h,达峰浓度分别为2054.8±757.8 ng·mL-1和2137.0±563.2 ng·mL-1,AUC0-15分别为5899.3±1757.3μg·mL-1和6032.4±1702.3μg·h·L-1.用面积法(AUC0-15)估算的受试制剂的相对生物利用度为98.9%±16.6%.结论:本试验建立的测定方法灵敏、准确、简便.新制剂盐酸伐昔洛韦片和市售盐酸伐昔洛韦片的药代动力学参数相近,统计学结果表明:两种盐酸伐昔洛韦片生物等效.     

两种替米沙坦片剂人体生物等效性研究

目的:研究国产(受试制剂)与进口(参比制剂)替米沙坦片的人体生物等效性。方法:采用LC-MS法,测定18名健康男性单次交叉口服参比制剂及受试制剂80 mg后血浆中不同时间点的药物浓度,计算其药动学参数和相对生物利用度。结果:受试制剂及参比制剂的主要药物动力学参数C_(max)分别为(428.8±108.6)和(420.7±93.0) ng·h~(-1)·ml~(-1);t_(max)分别为(1.0±0.3)和(1.3±0.5)h;AUC_(0→96)分别为(3041.8±409.4)和(3144.1±260.4)ng·h~(-1)·ml~(-1)。受试制剂相对生物利用度为96.8%±10.6%。结论:受试制剂与参比制剂具有生物等效性。     

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.     

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.     

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.