氨酚待因2号片的药代动力学及其相对生物利用度的研究

氨酚待因2号片是一改进的解热镇痛复方药,其中含扑热息痛300 mg/片,磷酸可待因15 mg/片。作为新的复方药,有必要对其药代动力学进行研究。本文用原料药配成水剂与片剂对比,计算相对生物利用度。用HPLC和GC-MS法分别检测了8位正常健康志愿者一次po氨酚待因2号片剂或水剂(30 mg磷酸可待因和600mg扑热息痛)后血浆中可待因和扑热息痛的含量。结果如下:po两片氨酚待因2号片后,扑热息痛的药代动力学符合二室模型;t_(peak)=0.74 h±s 0.43 h,C_(max)=8.04 mg·L~(-1)±s 3.96 mg·L~(-1),t_(1/2)=2.81 h±s1.09 h,Clr=0.39 L·h~(-1)±s 0.12 L·h~(-1),Cls=30.77 L·h~(-1)±s 9.02 L·h~(-1)。氨酚待因片中的可待因的药代动力学符合二室模型;t_(peak)=0.87 h±s 0.15 h,C_(max)=50.65μg·L~(-1)±s10.17μg·L~(-1),t_(1/2)=3.11h±s 0.49h,Clr=16.12L·h~(-1)±s 2.02L·h~(-1),Cls=173L·h~(-1)±s 11.40 L·h~(-1);po水剂对照药后,扑热息痛和可待因的药代动力学房室模型均与po片剂的药代规律相似,统计学上无显著差异(P>0.05)。扑热息痛和可待因的相对生物度分别为99.97％±s 10.55％,100.73％±s 7.85％。     

马来酸咪达唑仑片在汉族健康人体内的药动学研究

目的:研究马来酸咪达唑仑片在汉族健康人体内的药动学。方法:10名汉族健康受试者口服马来酸咪达唑仑片15mg后,用高效液相色谱法测定咪达唑仑血药浓度,用DAS2.0药动学软件拟合药动学参数。结果:受试者单剂量口服马来酸咪达唑仑片后的主要药动学参数分别为Cma(x103.11±26.37)ng·mL-1、tma(x1.52±0.75)h、t1/(22.96±0.77)h、Vz/F(170.08±50.97)L、CL/F(41.05±12.33)L·h-1、AUC0～1(2368.80±103.37)ng·h·mL-1、AUC0～∞(397.29±124.06)ng·h·mL-1。部分受试者的药-时曲线存在双峰现象。结论:咪达唑仑片的药动学参数个体差异较大,临床应用时应注意个体化给药。     

健康志愿者体内食物对盐酸二甲双胍片药代动力学的影响

目的 研究食物对盐酸二甲双胍片药代动力学的影响。方法 16名健康男性受试者随机分成两组,一组禁食12h后空腹口服格华止片1000 mg,另一组进统一餐后口服格华止片1000 mg,反相高效液相色谱法测定血浆中二甲双胍的浓度。结果 受试者空腹和餐后口服单剂量格华止片后,血浆中二甲双胍的C_(max)分别为2.19±0.50和2.10±0.49μg·mL~(-1),t_(max)分別为3.00±1.07和2.75±1.00h,t_(1/2)分别为3.58±0.40和3.12±0.40h,AUC_(0-16h)分别为14.53±3.74和14.33±3.04μg·h·mL~(-1),AUC_(0-∞)分别为15.32±4.02和14.95±3.24μg·mL~(-1)。结论 食物对格华止片的药代动力学无明显影响。     

罗哌卡因在手术病人的药代动力学

目的 对单剂量罗哌卡因硬膜外麻醉的手术病人进行药代动力学研究。方法 选择12例手术病人,硬膜外麻醉时,注入罗哌卡因150mg。血药浓度用反相高效液相色谱法测定。用3P97药代动力学计算程序拟合房室模型并计算药代动力学参数。结果 罗哌卡因的主要药代动力学参数:t_(max)为0.27±0.10h;C_(max)为1.86±0.40mg·L~(-1);t_(1/2 (α))为0.23±0.14h;t_(1/2 (β))为2.17±0.55 h;AUC为4.84±1.20 mg·h·L~(-1)。结论 罗哌卡因在手术病人中的代谢符合开放性二室模型。罗哌卡因在体内的消除不受疾病的影响。     

巴洛沙星片在健康人体内的药动学

目的:研究中国健康志愿者单次和多次口服巴洛沙星片的药动学。方法:12名健康志愿者,男女各半,单次给药试验口服(100 mg、200 mg、400 mg)3个剂量,多次给药试验口服剂量为每次200 mg,每日1次,连续5 d。采用高效液相色谱-紫外检测法测定巴洛沙星血药浓度,用DAS 2.0软件计算药动学参数。结果:主要药动学参数如下,单剂量(100 mg)c_(max)(1.42±s 0.25)mg·L~(-1),t_(max)(0.8±0.4)h,t_(1/2)(7.4±2.7)h,AUC_(0～∞)(9.8±1.7)mg·h·L~(-1);单剂量(200 mg)c_(max)(2.9±0.6)mg·L~(-1),t_(max)(0.9±0.4)h,t_(1/2)(7.2±1.1)h,AUC_(0～∞)(21±3)mg·h·L~(-1);单剂量(400 mg)c_(max)(5.6±1.4)mg·L~(-1),t_(max)(1.2±0.4)h,t_(1/2)(8.4±2.2)h,AUC_(0～∞)(44±12)mg·h·L~(-1)。多剂量c_(max)(2.9±0.8)mg·L~(-1),t_(max)(0.83±0.19)h,t_(1/2)(8.2±2.0)h,AUC_(0～∞)(21±5)mg·h·L~(-1),FI(93.7±1.4)%。结论:巴洛沙星在人体内符合二室模型,一级动力学过程。     

单剂量口服国产阿立哌唑片人体药动学研究

目的:建立测定阿立哌唑血浆药物浓度的HPLC-UV检测法,研究国产阿立哌唑片的人体药动学。方法:12例健康志愿受试者单剂量口服20mg国产阿立哌唑片,采用HPLC法测定给药后不同时间点血浆中阿立哌唑浓度,用DAS1．0处理经时血药浓度数据,计算主要药动学参数。结果:其主要药动学参数C_(max)为(108．4±22．5)μg·L~(-1),T_(max)为(4．9±0．7)h,AUC_(0-192h)为(5748．2±874．5)μg·h·L~(-1),t_(1/2)β为(107．43±29．03)h,Cl/F和V/F分别为(3．56±0．55)L·h~(-1)和(261．6±49．1)L。结论:国产阿立哌唑的血药浓度-时间曲线符合二室开放模型,男女单剂量口服阿立哌唑后药动学参数差异均无统计学意义。     

中国健康女性口服低剂量米非司酮片剂的人体药代动力学

目的 研究口服低剂量米非司酮在人体内的药代动力学特征。方法18名健康女性志愿者单剂量口服25mg米非司酮片,用HPLC-UV法检测血清中米非司酮及其代谢产物单去甲米非司酮的浓度,用3P97程序对血药浓度—时间数据进行统计处理。结果 米非司酮在人体内的动力学过程较好地符合一级吸收、二室模型,平均t_(max)为0.93h,平均C_(max)为1.12μg·mL_(-1)。平均末端消除相半衰期(t_(1/2 β))为25.4h,平均表观分布体积(V_d/F)为94.8L,平均药时曲线下面积AUC_(0～∝)为11.20μg·h·mL~(-1),平均总清除率为2.7L·h~(-1),平均滞留时间为29.5h。结论 口服25mg米非司酮在人体内药代动力学过程可以用一级吸收、开放的二室模型描述。     

机械通气患儿血浆中咪达唑仑及其代谢产物的测定

目的 建立测定人血浆中咪达唑仑及其代谢产物浓度的固相萃取和HPLC方法.方法 采用HPLC法分别测定29例ICU机械通气患儿给药24 h后血浆中咪达唑仑及其代谢产物浓度.色谱条件为：ZORBAX Eclipse XDB-C18色谱柱（4.6×250 mm,5 μm）;流动相为7.56 mmol/L硫酸铵溶液-乙腈,梯度洗脱,柱温25 ℃,流速1.0 ml/mmin,紫外检测波长254 nm.结果 4-羟基咪达唑仑、1＇-羟基咪达唑仑和咪达唑仑的保留时间分别为8.14、9.09和11.18 min.咪达唑仑及其羟基代谢产物的相对回收率98.88%～100.01%,RSD＜4%.29例患者血浆中咪达唑仑、1＇-羟基咪达唑仑和4-羟基咪达唑仑的平均浓度为0.68,0.28和0.08mg/L.结论 该方法适用于咪达唑仑及其代谢产物血药浓度的常规监测.     

液相色谱/质谱联用法测定国产辛伐他汀胶囊人体相对生物利用度

目的:建立辛伐他汀血浆中药物浓度的液质联用测定方法,研究其在人体的药代动力学及生物等效性。方法:18名健康男性受试者随机自身交叉给药,分别口服单剂量国产辛伐他汀胶囊剂和进口片剂20mg。用液相色谱/质谱联用测定血浆中辛伐他汀在人体内的浓度。结果;国产辛伐他汀胶囊剂和进口片剂主要药代动力学参数为:t_(max)分别为2.09±0.41h和2.13±0.47h,C_(max)分别为4.66±2.23μg·L~(-1)和4.71±2.45μg·L~(-1),AUC_(0-t)分别为19.42±3.99μg·h·~(-1)和19.76±4.13μg·h·L~(-1)。国产辛伐他汀胶囊剂的相对生物利用度为(98.3±10.8)％。结论:经统计学分析,国产辛伐他订胶囊剂和进口片剂具有生物等效性。     

酮康唑对大鼠鼻腔和灌胃给予咪达唑仑及其代谢产物药动学差异的影响

目的在系统比较大鼠鼻腔和灌胃给予咪达唑仑药动学特征的基础上,进一步比较酮康唑对2种给药途径药动学的影响。方法 24只大鼠随机分为4组,每组6只。其中2组分别经鼻腔或灌胃只给予咪达唑仑(1 mg?kg~(- 1)),另外2组联用细胞色素P450酶3A(CYP3A)抑制剂酮康唑(30 mg?kg~(- 1))后再分别经鼻腔或灌胃给予咪达唑仑,不同时间点采集血样,测定咪达唑仑和1′-羟基咪达唑仑浓度,计算药代动力学参数,并进行统计学分析。结果大鼠单独经鼻腔和灌胃给予咪达唑仑后,原型药物的达峰时间(T_(max))分别约为2和25 min,药时曲线下面积(AUC)分别为296和179μg?L~(-1)?h。合用酮康唑后,在鼻腔和灌胃给药条件下,咪达唑仑原型药物在大鼠体内的AUC分别增加到原来的2.1和3.3倍。但是,酮康唑不改变咪达唑仑鼻腔给药的T_(max),而合用酮康唑后,咪达唑仑灌胃给药的T_(max)延长至1.14h。结论咪达唑仑经鼻腔给药与经口服给药相比,吸收迅速、药物暴露量大,更适合于临床急救。咪达唑仑经鼻腔给药合用酮康唑后,不改变吸收速度,但抑制其代谢转化,药物体内驻留时间明显延长;咪达唑仑口服给药合并给予酮康唑后,吸收减慢,抑制代谢转化,体内药物暴露量明显增加。由于咪达唑仑的中枢镇静作用,2种途径合用酮康唑时均应考虑适当减少给药剂量或延长给药间隔。     

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.