盐酸环丙沙星胃漂浮型缓释片家犬体内生物利用度

目的检测盐酸环丙沙星胃漂浮缓释片与普通片在家犬体内的生物利用度.方法采用高效液相色谱法测定家犬体内的血药浓度.用3P97药动学程序拟合,计算药动学参数并评价生物等效性.结果盐酸环丙沙星普通片和胃漂浮缓释片的C(max)分别为(3.7±0.7)mg·L-1和(2.5±0.8)mg·L-1,t(max)分别为(1.8±0.8)h和(3.7±0.5)h,AUC(0→24)分别为(20.5±3.7)mg·h·L-1和(21.4±4.7)mg·h·L-1,MRT分剐为(5.7±0.5)h和(7.5±0.7)h,相对生物利用度Fr=104.2%.结论盐酸环丙沙星胃漂浮缓释片有很好的缓释效果,与参比制剂生物等效.     

盐酸二甲双胍/格列本脲复方胶囊的人体生物等效性及其药动学研究

目的:建立人血浆中盐酸二甲双胍与格列本脲的HPLC测定法,评价盐酸二甲双胍/格列本脲复方胶囊相对于格列本脲片与盐酸二甲双胍片联合应用是否具有生物等效性.方法:20名健康受试者单剂量交叉口服等剂量供试制剂或参比制剂(格列本脲5mg和盐酸二甲双胍1 000mg)后不同时间点采血,分别采用HPLC-UV,HPLC-MS检测法,测定血浆中盐酸二甲双胍及格列本脲的药物浓度,计算其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:供试制剂与参比制剂中盐酸二甲双胍AUC0-12分别为(16.25±3.50)和(16.79±3.99)mg·h·L-1,Cmax分别为(3.35±0.71)和(3.47±0.77)mg·L-1,Tmax分别为(1.9±0.3)和(1.9±0.4)h,t1/2ke分别为(2.81±0.31)和(2.79±0.33)h.供试制剂与参比制剂中格列本脲AUC0～15分别为(1.236±0.523)和(1.170±0.522)mg·h·L-1,Cmax分别为(0.258±0.075)和(0.264±0.073)mg·L-1,Tmax分别为(2.5±0.4)和(2.4±0.4)h,t1/2ke分别为(3.93±1.61)和(3.36±0.62)h.两制剂中盐酸二甲双胍及格列本脲主要药动学参数经统计学分析差异无显著性.结论:该方法简便灵敏,盐酸二甲双胍/格列本脲复方胶囊相对于格列本脲片与盐酸二甲双胍片联合应用具有生物等效性.     

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.     

盐酸二甲双胍缓释片的药代动力学及相对生物利用度研究

目的:研究盐酸二甲双胍缓释片的药代动力学和通过与普通片的药代参数的比较得出相对于普通片的相对生物利用度.方法:采用HPLC法测定20名健康男性志愿者,随机自身交叉单剂量和多剂量口服盐酸二甲双胍缓释片和普通片500rmg后的血药浓度,得出两种剂型的药时曲线,计算各药代参数和相对生物利用度.结果:20名健康志愿者单次口服盐酸二甲双胍缓释片和普通片500 mg的主要药代动力学参数分别为:t1/2(4.64±0.95)h和(4.44±0.91)h;Cmax(0.89±0.25)μg·ml-1和(1.51±0.42)μg·ml-1;tmax(4.2±0.9)h和(1.8±0.5)h;MRT(9.10±1.04)h和(6.07±0.63)h;AUC0-24h(8.76±2.59)μg·h·ml-1和(9.00±2.23)μg·h·ml-1;AUC0-∞(9.21±2.51)μg·h·ml-1和(9.34±2.28)μg·h·ml-1.多次口服盐酸二甲双胍缓释片和普通片(500 mg×5 d)的主要药代动力学参数分别为:Cmax(0.88±0.22)μg·ml-1和(1.39±0.39)μg·ml-1;Cmin(0.05±0.01)μg·ml-1和(0.03±0.01)μg·ml-1;tmax(4.1±1.0)h和(2.1±0.4)h;AUCss(8.34±2.67)μg·h·ml-1和(8.55±2.08)μg·h·ml-1;DF(2.24±0.47)%和(3.87±0.66)%(DF为血药浓度的波动度).盐酸二甲双胍缓释片相对于普通片的相对生物利用度(F)为(96.8±11.5)%.结论:lnAUC经方差分析和双单侧t经检验,无显著性差异,因此两种制剂具有生物等效性.lnCmax经两种方法分析有显著性差异(P＜0.05),Tmax经非参数检验(Wilcoxon符号秩序法)有显著性差异(P＜0.05),且受试缓释片较参比普通片的Gmax小、Tmax有所延长,表明受试制剂具有缓释特性.     

离子对RP-HPLC法研究盐酸二甲双胍片的相对生物利用度

目的:研究盐酸二甲双胍片在正常人体内的相对生物利用度.方法:20名健康志愿者随机分为两组,分别交叉口服受试片和参比片,采用离子对色谱法测定血浆中药物浓度,以计算盐酸二甲双胍片的主要药动学参数及相对生物利用度.结果:受试制剂和参比制剂的tmax分别为2.0±0.7 h和2.3±0.5 h,Cmax分别为2.32±0.47 mg·L-1和2.51±0.58 mg·L-1,用梯形法计算所得的AUCO-12分别为12.30±2.40 mg·h·L-1和12.49±2.54 mg·h·L-1;经t检验,两种制剂的药代动力学无显著性差异;与参比制剂相比,受试制剂的相对生物利用度为99.1%±11.3%.结论:两种制剂具有生物等效性.     

烟酸缓释胶囊在家犬体内的生物利用度

目的:研究家犬口服烟酸缓释胶囊的药动学及相对生物利用度.方法:家犬6只采用双周期交叉给药的实验方法,用离子对反相高效液相色谱法测定烟酸在家犬血浆内的浓度,用3p97处理药动学参数进而计算相对生物利用度.结果:烟酸缓释胶囊和市售普通片在家犬体内过程均符合单隔室模型,其主要的药动学参数T max ,C max 和AUC 0-t 分别是( 2.9 ± 1.6 ),( 0.9 ± 0.6 ) h;( 5.7 ± 1.6 ),( 11.7 ± 5.9 ) mg·L -1 ;( 24.8 ± 13.8 ),( 22.4 ± 10.6 ) mg·L -1 ·h.结论:烟酸缓释胶囊具有明显的缓释特征,生物利用度与市售普通片等效.     

头孢泊肟酯片人体药动学及生物等效性评价

目的:研究国产和进口头孢泊肟酯片在人体的药动学和生物等效性.方法:20名健康男性志愿者随机交叉口服单剂量国产和进口头孢泊肟酯片200 mg,采用高效液相色谱法测定其活性代谢产物头孢泊肟的经时血药浓度,计算其药动学参数和相对生物利用度,评价两种制剂的生物等效性.结果:国产和进口头孢泊肟酯片的主要药动学参数t1/2分别为(2.6±0.9)h和(2.7±1.1)h,tmax分别为(3.0±0.6)h和(3.0±0.5)h,Cmax分别为(4.3±0.7)mg·L-1和(4.2±0.8)mg·L-1,AUC0→12分别为(21.1±4.8)mg·h·L-1和(21.9±5.5)mg·h·L-1,AUC0→∞分别为(23.1±6.1)mg·h·L-1和(24.0±6.6)mg·h·L-1,国产头孢泊肟酯片的相对生物利用度为(97.8±13.5)%(F0→12)和(97.2±15.9)%(F0→∞).结论:经统计学分析,两种制剂具有生物等效性.     

酮基布洛芬单室渗透泵片在家犬体内的药动学和相对生物利用度

目的研究家犬口服酮基布洛芬单室渗透泵片的药动学和相对生物利用度.方法家犬6只采用双周期交叉给药,用高效液相色谱法测定酮基布洛芬的血药浓度,用3P97处理药动学参数进而计算相对生物学利用度.结果酮基布洛芬单室渗透泵片和市售普通片在家犬体内过程均符合单室模型,其主要的药动学参数Tmax,Cmax和AUC0-t分别是(2.51±0.67),(1.44±0.26)h;(7.12±1.27),(6.01±1.65)mg·L-1;(66.15±2.32),(59.28±3.69)μg·h·mL-1.结论酮基布洛芬单室渗透泵片具有明显的缓释特征,生物利用度与市售普通片等效.     

盐酸阿夫唑嗪缓释片人体内生物利用度

目的:比较盐酸阿呋唑嗪缓释片和进口阿呋唑嗪普通片的人体生物利用度和生物等效性。方法:20名男性健康受试者自身交叉口服单剂量盐酸阿呋唑嗪缓释片和进口普通片5mg,用高效液相色谱(HPLC)法测定人血浆中盐酸阿呋唑嗪的浓度,计算药动学参数,以方差分析与双向单侧t检验进行统计学分析。结果:盐酸阿呋唑嗪缓释片和进口普通片的Cmax分别为(28.9±9.6)μg.L-1和(32.9±10.2)μg.L-1,tmax分别为(2.7±0.6)h和(1.4±1.0)h,AUC0→∞分别为(221.1±59.5)μg.L-1.h和(245.7±67.2)μg.L-1.h。两药各药动学参数间均无统计学差异。盐酸阿呋唑嗪缓释片的相对生物利用度为(92.2±13.2)%。结论:两种制剂具有生物等效性。     

国产与进口富马酸奎的平片的药动学比较及相对生物利用度

目的:研究富马酸奎的平片的药动学及相对生物利用度.方法:受试者交叉口服单剂量(100mg)国产片与进口片,用高效液相色谱法测定血药浓度.结果:两种片剂的主要药动学参数:Tmax分别为(1.7±0.8)h与(1.6±0.7)h,Cmax分别为(100.4±18 9)μg·L-1与(100.0±17.8)μg·L-1,AUC0-t分别为(246.8±29.4)μg·L-1·h与(244.7±28.8)μg·L-1·h,AUC0-∞分别为(250.7±30.2)μg·L-1·h与(248.9±29.6)μg·L-1·h,T1/2分别为(1.8±0.5)h与(1.8±0.4)h,国产片相对于进口片的生物利用度为(101.9±7.4)%.结论:两种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.     

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.