磷酸可待因缓释片人体多剂量药动学及生物利用度

目的研究磷酸可待因缓释片在肿瘤患者体内的多剂量达稳态药动学和生物利用度.方法采用RP-HPLC法测定可待因的血药浓度,研究10名肿瘤患者多剂量口服磷酸可待因缓释片及普通片达稳态后的药动学及相对生物利用度.结果多剂量口服缓释片及普通片达稳态后,AUCss0→τ分别为(599.8±137.9)和(242.4±51.8)ng     

左旋氧氟沙星的人体相对生物利用度研究

目的比较国产盐酸左氧氟沙星胶囊(A)与进口左旋氧氟沙星片(可乐必妥片,B)的人体相对生物利用度.方法对10名男性健康志愿者交叉单剂量口服A和B各200mg后,采用HPLC测定不同时间血药浓度,绘制血药浓度-时间曲线,计算有关药物动力学参数和相对生物利用度.结果A和B两种制剂Cmax分别为(2153.5±624.5)ng/ml和(2083.0±716.6)ng/ml;Tmax分别为(0.75±0.35)h和(1.15±0.58)h,T1/2分别为(7.20±0.6)h和(7.67±1.2)h,AUC分别为(11656.5±2131.9)ng·h/ml和(11908.7±2491.2)ng·h/ml.经统计分析,两种制剂的药物动力学参数无显著性差异(P＞0.05).国产盐酸左氧氟沙星胶囊的相对生物利用度为(102.0±8.7)%.结论两种制剂体内生物作用等效.     

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。     

单硝酸异山梨酯缓释片生物利用度研究

目的:研究上海信谊万象药业股份有限公司研制的单硝酸异山梨酯缓释片的生物利用度。方法:10名健康男性口服单剂量和多剂量单硝酸异山梨酯缓释片(40mg/片),并与口服山东鲁南制药厂生产的普通片(20mg/片)作比较,应用气相色谱仪测定血药浓度,求得相关药代动力学参数。结果:经统计分析,缓释片和普通片的Cmax、Tmax及MRT有显著性差异。在稳态时,单剂量及多剂量的缓释片(40mg)生物利用度相对于普通片(20mg×2)分别为(106.0±18.3)%和(93.6±12.4)%结论:单硝酸异山梨酯缓释片与普通片生物等效,但缓释片仅需日服1次,方便使用。     

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1000mg后的血药浓度,得出相应的药时曲线,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1000mg的主要药代动力学参数分别为:t1/2(5.79±3.05)h和(6.87±4.59)h;Cmax(1185.75±318.92)ng.mL-1和(1232.19±321.91)ng.mL-1;tmax(3.80±1.01)h和(4.05±0.83)h;MRT(8.96±3.00)h和(10.32±4.70)h;AUC0-24h(8724.58±3203.33)ng.h.mL-1和(8642.79±2512.83)ng.h.mL-1;AUC0-∞(9631.89±3796.98)ng.h.mL-1和(9977.48±3317.60)ng.h.mL-1。多次口服盐酸二甲双胍缓释片(1000mg×7d)的主要药代动力学参数分别为:Cmax(1300.91±250.39)ng.mL-1和(1355.00±321.86)ng.mL-1;Cmin(90.59±20.97)ng.mL-1和(87.93±23.73)ng.mL-1;tmax(4.15±1.14)h和(4.60±0.82)h;AUCss(11120.50±2708.06)ng.h.mL-1和(11570.97±3513.51)ng.h.mL-1;DF(2.73±0.57)%和(2.76±0.62)%(DF为血药浓度的波动度)。两种制剂的药动学参数无显著性差异(P>0.05),受试制剂的相对生物利用度(F)为(98.40±15.50)%。结论两种制剂具有生物等效性。     

阿西美辛缓释片人体相对生物等效性

目的对自制制剂阿西美辛缓释片和参比制剂缓释胶囊进行人体生物等效性评价.方法10名健康志愿者采用自身对照给药方案,单剂量、多剂量口服阿西美辛缓释片或缓释胶囊.采用HPLC法测定阿西美辛及其活性代谢产物吲哚美辛的血药浓度,用3P97计算机程序求算药物动力学参数,并进行生物等效性评价.结果阿西美辛缓释片、缓释胶囊的主要药物动力学参数T1/2分别为(9.349±2.049)和(8.130±2.253)h,tmax分别为(3.700±0.483)和(3.600±0.516)h,cmax分别为(1.067±0.124)和(1.086±0.122)μg/ml,AUC0→24分别为(8.055±1.350)和(7.981±1.306)h*μg/ml,阿西美辛缓释片的相对生物利用度为(102.7±25.6)%.结论经双单侧t检验结果显示两种制剂生物等效.     

磷酸可待因缓释片人体药物动力学及生物利用度

目的:研究磷酸可待因缓释片在正常人体内的药物动力学和生物利用度.方法:采用RP-HPLC法测定可待因的血药浓度,研究8名志愿者单剂量po 90mg磷酸可待因缓释片及普通片后药物动力学及相对生物利用度;另对8例志愿者po 90mg磷酸可待因缓释片及iv磷酸可待因30mg后绝对生物利用度进行了研究.结果:单剂量po 90mg缓释片及普通片后,AUC_(0→∞)分别为(524.17±129.61)和(337.90±85.20)ng·h/ml;t_(max)分别为(2.75±0.46)和(1.31±0.26)h,C_(max)分别为(74.34±7.84)和(89.63±10.58)ng/ml,两种制剂的AUC_(0→∞)、t_(max)、C_(max)均有显著性差异(P<0.05).磷酸可待因缓释片相对及绝对生物利用度分别为(156.1±6.3)%和(84.1±4.8)%.结论:缓释片与普通片为生物不等效制剂.     

尼莫地平漂浮缓释片的人体药物动力学及相对生物利用度

目的:比较尼莫地平(Nim)漂浮缓释片与普通片的药物动力学、相对生物利用度及体内外相关性.方法:10例男性健康受试者自身交叉对照、单剂量po Nim漂浮缓释片或普通片各120mg,采用HPLC法测定血浆Nim浓度,单室模型拟合药物动力学参数.结果:Nim缓释片和普通片的t_(max)分别为(2.83±0.45)和(0.87±0.27)h(P<0.01),C_(max)分别为(32.82±6.36)和(48.71±8.94)ng/ml(P<0.01),AUC分别为(204.81±45.03)和(159.98±39.96)h·ng/ml(P<0.01).数据经对数转换后进行双单侧检验,两种制剂生物不等效;缓释片的相对生物利用度为(129.89±17.02)%;其体内吸收与体外释药具有显著的相关性(P<0.01).结论:Nim漂浮缓释片生物利用度优于普通片,达到剂型设计要求.     

氯雷他定片人体生物利用度研究

目的:研究氯雷他定片在正常人体内药代动力学与相对生物利用度。方法:利用HPLC法测定20名志愿受试者随机交叉口服单剂量重庆或上海氯雷他定片(LORAL或LORAS)20mg后的血药浓度,用3p97软件包计算两者的药代动力学参数与相对生物利用度。结果:测试药物与对照药的药鄄时曲线均符合口服吸收一室模型。Tmax分别为(0.99±0.48)h和(0.95±0.54)h;Cmax分别为(13.11±9.15)ng/ml和(12.18±7.04)ng/ml;AUC0鄄T分别为(30.21±17.69)ng·h/ml与(30.96±18.27)ng·h/ml;t1/2Ke分别为(1.66±0.63)h和(1.64±0.54)h;经配对t检验,两制剂药代动力学参数无显著性差异(P>0.05)。结论:重庆氯雷他定片相对于上海片剂的生物利用度为97.58﹪,经方差分析、双单测t检验及1鄄2α置信区间法统计分析,两种片剂具有生物等效性。     

每日1次美斯地浓缓释片体内药代动力学与生物等效性研究

目的研究美斯地浓缓释片在兔体内单剂量和多剂量的药代动力学和生物等效性,为临床研究提供参考和依据。方法 6只兔采用自身交叉给药方案,分别单剂量及多剂量口服美斯地浓缓释片和普通片后,采用高效液相色谱法(HPLC)测定血浆中美斯地浓浓度。结果单次口服缓释片和普通片后主要药动学参数为:Tmax分别为(6±0)和(2±0)h;Cmax分别为(14.446±0.279)和(17.944±0.919)μg.L-1;T 12分别为(5.449±2.779)和(2.733±0.652)h;AUC0-t分别为(231.076±4.408)和(196.127±4.009)μg.h.L-1;AUC0-∞分别为(254.644±6.49)和(198.385±3.934)μg.h.L-1,相对生物利用度F为(117.3±11.0)%。多次口服缓释片和普通片达稳态后主要药动学参数:Cmax分别为(18.391±0.16)和(25.477±0.177)μg.L-1;Cmin分别为(3.421±0.186)和(6.612±0.254)μg.L-1;Cav分别为(12.99±0.055)和(16.088±0.132)μg.L-1;AUCss分别为(155.881±0.655)和(193.057±1.591)μg.h.L-1;DF分别为(1.152±0.012)和(1.173±0.019),相对生物利用度F为(106.7±6.4)%。结论美斯地浓缓释片与普通片两种制剂生物等效,且美斯地浓缓释片具有明显的缓释特征。     

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.     

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.