单硝酸异山梨酯阿司匹林缓释片在人体内的药动学及生物等效性

20名健康受试者随机交叉单剂量(单硝酸异山梨酯60mg和阿司匹林75mg)和多剂量口服单硝酸异山梨酯阿司匹林缓释片(受试制剂)、单硝酸异山梨酯缓释片及阿司匹林肠溶片(参比制剂)后,分别采用HPLC-MS法和HPLC-UV法测定人血浆中单硝酸异山梨酯和水杨酸浓度。药动学参数见文中表1和表2。经双单侧t检验结果表明,以单硝酸异山梨酯为研究对象,两制剂具有生物等效性;以阿司匹林为研究对象,两制剂的吸收程度相当,但受试制剂吸收速度较快。     

阿司匹林肠溶片在犬体内的药代动力学研究

目的对改进工艺后生产的25 mg阿司匹林肠溶片的体内药代动力学进行研究。方法以德国拜耳公司生产的阿司匹林肠溶片(100 mg)为对照制剂,进行了比格犬体内药代动力学实验,采用DAS药动学程序进行模型分析和参数计算,并与对照制剂进行了相对生物利用度比较和体内外相关性研究。结果比格犬单剂量给药时,该肠溶片的体内药物动力学符合一级吸收二室模型;自制的阿司匹林肠溶片相对于德国拜耳的阿司匹林肠溶片生物利用度为(86±3.7)%;自制的阿司匹林肠溶片在比格犬体内平均驻留时间为3.376 h,达峰时间3.0 h,达峰浓度46 mg.L-1。结论研制的阿司匹林肠溶片和德国拜耳公司的阿司匹林肠溶片生物等效性基本一致。     

氢溴酸加兰他敏缓释片的人体药代动力学及缓释特性评价

目的研究氢溴酸加兰他敏缓释片和普通片单剂量和多剂量给药后在健康受试者体内的药代动力学特征,并评价缓释片的缓释特性。方法建立以纳洛酮(naloxone)为内标的LC-MS测定方法,测定20名健康男性受试者按双交叉试验单剂量和多剂量服用氢溴酸加兰他敏缓释片与普通片后血浆中加兰他敏的浓度,并计算药代动力学参数和生物利用度,并评价缓释片的缓释特性。结果单剂量给药后,缓释片与普通片的HVD12Cmax分别为(15.4±1.7)h和(5.4±2.5)h;与普通片相比缓释片的延迟商R△为3.4±1.4;缓释片与普通片的Tmax分别为(4.4±1.5)h和(1.3±1.2)h;Cmax分别为(27.5±2.9)μg·L-1和(53.7±12.7)μg·L-1;缓释片的缓释特征明显。缓释片的相对生物利用度为(95.9±14.2)%。多剂量给药后,缓释片与普通片的CmSSax分别为(58.8±9.4)μg·L-1和(52.0±6.9)μg·L-1,CSmSin分别为(16.2±4.0)μg·L-1和(22.5±5.0)μg·L-1,Cav分别为(39.0±3.9)μg·L-1和(37.1±5.0)μg·L-1,DF分别为1.1±0.3和0.8±0.1;双单侧t检验结果表明两制剂的AUCss、CmSSax、Cav生物等效。结论缓释片与普通片吸收程度生物等效,该缓释片显示出明显的缓释特征。     

吲达帕胺缓释胶囊生物等效性及药物动力学研究

20名健康男性受试者单剂量和多剂量交叉口服国产吲达帕胺缓释胶囊(受试制剂)与进口吲达帕胺缓释片(参比制剂)。采用HPLC/MS法测定全血中吲达帕胺的浓度。单剂量口服受试和参比制剂后的Cmax分别为(29.1±5.4)和(33.0±6.0)ng/ml,Tmax分别为(12.0±4.7)和(15.0±5.8)h,AUC0-72h分别为(1106.9±293.3)和(1179.8±316.8)ng·ml-1·h。受试制剂的相对生物利用度为(95.1±13.5)%。多剂量口服两种制剂4d后达稳态,波动度分别为(41.5±15.0)%和(46.4±19.5)%。双单侧t检验结果表明,两种制剂具有生物等效性。     

盐酸二甲双胍缓释片人体相对生物利用度研究

目的:评价盐酸二甲双胍缓释片与普通片的人体相对生物利用度。方法:采用自身交叉试验设计,18名健康男性志愿者单剂量及多剂量口服盐酸二甲双胍普通片或缓释片,血药浓度采用HPLC-UV法测定。研究盐酸二甲双胍缓释片的相对生物利用度,并对缓释制剂的缓释情况进行评价。结果:盐酸二甲双胍缓释片和普通片单剂量给药后的Cmax分别为(0.779±0.368)和(1.189±0.528)μg/mL;Tmax分别为(2.67±1.26)和(1.56±0.56)h;AUC0→t分别为(7.176±3.134)和(7.006±3.016)μg.h.mL-1。盐酸二甲双胍缓释片的相对生物利用度为(103.38±14.68)%。盐酸二甲双胍缓释片和普通片多次给药后的Cmax分别为(0.783±0.192)和(1.037±0.281)μg/mL;Tmax分别为(3.12±0.58)和(1.56±0.29)h;AUC0→t分别为(6.585±1.647)和(4.158±1.033)μg.h.mL-1;波动度DF分别为(2.71±0.68)%和(2.79±0.56)%。结论:盐酸二甲双胍缓释片(每片含盐酸二甲双胍500 mg)每天1次口服与等剂量市售盐酸二甲双胍普通片每天2次口服具有生物等效性。     

阿奇霉素肠溶片的人体药动学与生物等效性研究

目的建立测定阿奇霉素血药浓度的微生物法,并评价阿奇霉素肠溶片与普通阿奇霉素片的生物等效性。方法采用微生物法,测定24例健康受试者单剂量交叉口服受试制剂阿奇霉素肠溶片或参比制剂普通阿奇霉素片500 mg后不同时间点的血浆药物浓度,计算药动学参数和相对生物利用度,评价两制剂的生物等效性。结果阿奇霉素肠溶片与普通阿奇霉素片AUC0→144 h分别为(21.021±4.053)和(20.597±3.850)mg.h-1.L-1,Cmax分别为(0.583±0.073)和(0.603±0.061)mg.L-1,tmax分别为(3.900±0.800)和(3.000±0.700)h,t1/2分别为(29.799±1.935)和(28.850±1.598)h。两制剂主要药动学参数差异无显著性。结论该实验所建立的方法简便快捷,两制剂具有生物等效性,但受试制剂阿奇霉素肠溶片在人体内的吸收速度较参比制剂阿奇霉素普通片慢。     

阿司匹林缓释胶囊在健康志愿者体内的生物等效性

目的:研究阿司匹林缓释胶囊的人体相对生物利用度和生物等效性。方法:健康志愿者20名,用随机双交叉试验方法,单剂量及多剂量po试验及对照制剂162.5和150 mg,剂间间隔为2周。用高效液相色谱法测定阿司匹林体内活性代谢产物水杨酸的血浆药物浓度,计算两者的药代动力学参数及相对生物利用度,并进行生物等效件评价。结果:单剂量口服试验及对照制剂的C_(max)分别为2.77±0.68和2.62±0.83 mg L;t_(max)分别为2.87±2.52和3.48±2.09 h;t_(1/2)分别为11.07±4.46和12.41±5.03 h;AUC_(0-60)分别为62.50±16.06和57.36±14.70 mg·h·L~(-1);AUC_(O-inf)分别为65.50±18.71和61.33±17.44 mg·h·L~(-1);相对生物利用度为(110.9±19.1)％。多剂量口服实验制剂和参比制剂达到稳态后的C_(min)分别为0.72±0.26和0.78±0.16mg·L~(-1);C_(max)分别为4.78±1.48和4.49±1.45 mg·L~(-1);t_(1/2)分别为 9.06±1.50和8.87±1.39 h;AUC~(SS)分别为64.22±14.71和61.79±13.22 mg·h·L~(-1);DF分别为1.44±0.43和1.37±0.48;相对生物利用度为(108.9±35.5)％。结论:两制剂在单剂量和多剂量条件下具有生物等效性。     

阿司匹林壳聚糖缓释片兔体内药物动力学研究

目的　研究阿司匹林壳聚糖缓释片的体内药物动力学。方法　采用随机分组自身对照实验 ,分别给予家兔口服阿司匹林壳聚糖缓释片和阿司匹林肠溶片 ,定时收集血样 ,以分光光度法测定血药浓度 ,用 3P97药动学程序进行处理。结果　缓释片和肠溶片的 Tmax分别为 (6 .90± 0 .5 2 ) h和 (4.6 6± 0 .4 0 ) h;Cmax分别为 (5 .33±0 .38)和 (9.39± 0 .5 3) mg· L-1;AUC0→ 2 4h分别为 (6 3.4 5± 1.19)和 (6 4.85± 1.96 ) mg·h· L-1;相对生物利用度为 (97.92± 0 .0 3) %。结论　阿司匹林壳聚糖缓释片在家兔体内有缓释特征 ,可望为预防和治疗血栓形成提供一个新的剂型。     

格列齐特缓释片人体药动学及生物等效性研究

目的:研究格列齐特缓释片的药动学及相对生物利用度,验证国产与进口格列齐特缓释片的生物等效性。方法:采用拉丁方试验设计,研究受试者在空腹条件下分别单剂量和多剂量口服格列齐特缓释片后,采用高效液相色谱法测定人血浆中格列齐特的浓度,计算其药动学参数和相对生物利用度,评价2制剂的生物等效性。结果:单剂量口服格列齐特缓释片受试制剂(国产)和参比制剂(进口)的主要药动学参数分别为:tma(x6.71±1.43)、(7.38±1.50)h,Cma(x0.813±0.178)、(0.782±0.129)μg.mL-1,AUC0～7(221.29±5.86)、(21.09±5.34)μg.h.mL-1,AUC0～∞(23.19±7.49)、(23.15±5.64)μg.h.mL-1,t1/2k(e18.79±5.24)、(20.03±5.67)h;多剂量口服格列齐特缓释片达稳态后2制剂主要药动学参数分别为:AUCs(s27.85±9.77)、(27.63±10.84)μg.h.mL-1,Cssmax(1.892±0.503)、(1.829±0.521)μg.mL-1,tssma(x5.33±1.24)、(6.13±1.42)h,Cssmi(n0.771±0.379)、(0.830±0.478)μg.mL-1,血药浓度波动度DF(103.8±40.0)%、(97.6±52.9)%。结论:2制剂具有生物等效性。     

2种奥沙普秦肠溶片的人体相对生物利用度研究

目的:比较2种国产奥沙普秦肠溶片的相对生物利用度。方法:20名健康志愿者分别单剂量交叉口服受试制剂和对照制剂各400mg,采用高效液相色谱法测定人血浆中奥沙普秦浓度;采用3p97软件计算二者药动学参数,并计算生物利用度。结果:受试制剂和对照制剂的t1/2β分别为(73.468±24.354)、(73.556±24.406)h,tmax分别为(13.275±8.012)、(13.200±15.154)h,Cmax分别为(44.283±7.535)、(45.429±15.107)μg/ml,AUC0～Tn分别为(4471.792±1387.724)、(4234.328±1741.380)(μg.h)/ml,AUC0～inf分别为(5040.407±2092.744)、(4858.292±2423.656)(μg.h)/ml,均无统计学差异;受试制剂的相对生物利用度为(112.8±38.5)%。结论:2种国产奥沙普秦肠溶片具有生物等效性。     

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.