亚叶酸钙片的人体生物利用度及生物等效性研究

目的:研究亚叶酸钙片在健康受试者体内的相对生物利用度和生物等效性.方法:采用两制剂双周期随机交叉试验设计,18名男性健康受试者单剂量口服亚叶酸钙片或参比片剂75mg,用HPLC测定血浆亚叶酸浓度.采用3P97药动学程序进行数据处理.结果:试验片剂与参比片剂的AUC0-24h分别为(4608.68±806.72)ng·ml-1·h和(4868.73±909.83)ng·ml-1·h;Cmax分别为(484.82±72.87)ng·ml-1和(499.50±108.19)ng·ml-1;Tmax分别为(2.33±0.30)h和(2.47±0.27)h.结论:两种制剂主要药动学参数均无显著性差异.与参比片剂相比,试验片剂的相对生物利用度为(96.48±18.60)%,两者具有生物等效性.     

瑞舒伐他汀钙胶囊和片剂在健康人体内药动学和生物等效性研究

目的:研究瑞舒伐他汀钙胶囊和片剂在健康人体内的药动学过程和相对生物利用度。方法:健康志愿者24名,随机双交叉单剂量口服瑞舒伐他汀钙胶囊(受试制剂)和瑞舒伐他汀钙片(参比制剂),剂量均为20 mg,采用HPLC-MS/MS测定血浆中瑞舒伐他汀钙的浓度,用DAS 3.0药动学程序计算药动学参数和生物利用度,并进行生物等效性评价。结果:单剂量口服瑞舒伐他汀钙受试和参比制剂后,血浆瑞舒伐他汀的tmax分别为(3.56±1.68)h和(3.63±1.56)h;Cmax分别为(21.17±13.74)ng·ml-1和(26.33±23.22)ng·ml-1;t1/2分别为(10.68±5.50)h和(9.04±6.00)h;AUC0-t分别为(219.31±146.09)ng·h·ml-1和(252.43±194.96)ng·h·ml-1;AUC0-∞分别为(225.32±146.76)ng·h·ml-1和(257.24±194.61)ng·h·ml-1,AUC0-t、AUC0-∞和Cmax的90%置信区间分别为81.1%~106%,81.8%~105.4%和77.9%~104.5%。受试制剂的相对生物利用度F为(100.7±54.1)%。结论:瑞舒伐他汀钙受试制剂与参比制剂具有生物等效性。     

格列美脲分散片人体生物等效性研究

目的:比较两种格列美脲制剂的人体生物等效性.方法:20名健康男性志愿者随机交叉口服单剂量格列美脲分散片(受试制剂)与格列美脲片(参比制剂)2 mg,采用HPLC-MS法测定血浆中格列美脲浓度,用DAS 2.1软件计算药动学参数和生物利用度.结果:口服格列美脲受试制剂与参比制剂后的药动学参数分别为Cmax( 135.4±40.3)和(146.5±39.2) ng·ml-1,tmax(3.2±1.2)和(2.8±0.9)h,t1/2(7.3±3.9)和(6.7±2.8)h,AUC0～36 (757.1±217.2)和(849.4±250.4 )ng·h·ml-1,AUC0～∞(784.0±217.4)和(871.5±265.2) ng·h·ml-1.受试制剂的相对生物利用度为(90.7±17.5)％.结论:两种格列美脲制剂具有生物等效性.     

奥美拉唑肠溶胶囊人体相对生物利用度和生物等效性研究

目的:比较两种奥美拉唑肠溶胶囊的人体相对生物利用度,并做出生物等效性评价,以考察试验制剂的药品质量.方法:按照两制剂两周期随机交叉设计,19名男性健康志愿者单剂量口服试验胶囊(20mg×2)和参比胶囊(40mg).采用HPLC法测定血浆奥美拉唑浓度.运用DAS2.0软件计算药动学参数,并进行统计学分析.结果:单剂量口服40mg的奥美拉唑肠溶试验胶囊和参比胶囊后,AUC0?12分别为(3184.81±2055.44)ng·h·ml-1和(3062.46±1957.74)ng·h·ml-1,AUC0?8分别为(3361.55±2370.29)ng·h·ml-1和(3186.89±2042.69)ng·h·ml-1;Cmax分别为(1066.44±482.99)ng·ml-1和(1072.99±472.30)ng·ml-1;Tmax分别为(2.50±0.82)h和(2.37±0.72)h;受试胶囊对参比胶囊平均相对生物利用度为(107.33±23.44)%.结论:试验胶囊与参比胶囊具生物等效性.     

盐酸格拉司琼口崩片在健康人体内的药动学及生物等效性

研究了盐酸格拉司琼口崩片的药动学,并以盐酸格拉司琼片为参比制剂,评价其生物等效性.20例健康志愿者单剂量随机交叉口服受试制剂和参比制剂各1 mg,用HPLC-荧光法测定血药浓度.受试制剂与参比制剂的主要药动学参数分别为cmax(3.32±0.93)和(3.20±0.86)ng/ml,tmax(1.65±0.52)和(1.88±0.86)h,t1/2(6.16±0.90)和(6.22±0.81)h,AUC0→t(19.50±8.10)和(19.70±7.78)ng·h·ml-1,AUC0→∞(20.90±9.11)和(21.10±8.57)ng·h·ml-1.受试制剂的相对生物利用度为(99.8±15.3)%,结果表明两种制剂具有生物等效性.     

氟比洛芬微乳大鼠药动学研究

目的评价自制氟比洛芬微乳在大鼠体内的药动学和相对生物利用度。方法两组SD雄性大鼠分别单剂量给予氟比洛芬微乳和氟比洛芬片,采用HPLC测定血药浓度。应用3P87药动学程序对数据进行处理计算药动学参数。结果单剂量给药后氟比洛芬微乳和氟比洛芬片的主要药动学参数Cmax分别为(4976.1±500.9)ng·mL-1和(3684.0±500.6)ng·mL-1,tmax分别为(1.17±0.37)h和(2.33±0.46)h,AUC0→36分别为(44613.5±8515.7)ng·mL-1和(34126.5±7909.6)ng·h·mL-1,相对生物利用度为130.46%。结论以市售氟比洛芬片为参比制剂,氟比洛芬微乳在大鼠体内的生物利用度明显提高。     

人血浆中胺碘酮分散片的药动学研究

建立TLC-MS法测定人血浆中胺碘酮的浓度,并研究了18名健康受试者随机交叉口服胺碘酮分散片(受试制剂)和胺碘酮片剂(参比制剂)0.4g后的药动学.口服受试和参比制剂后的药动学参数分别为cmax(419.96±211.72)和(414.85±166.66)ng/ml,tmax(4.2±1.2)和(3.8±0.9)h,t1/2(38.8±20.4)和(39.6±12.5)h,AUC0-96h(6375.29±3093.14)和(6518.38±3101.07)ng·h·ml-1,AUC0→∞(7165.29±3680.16)和(7325.51±3478.09)ng·h·ml-1.受试制剂的相对生物利用度为(98.37±8.38)%.双单侧t检验结果表明,两种制剂具有生物等效性.     

维生素K1软胶囊的人体药动学及生物等效性研究

目的:建立人血浆中维生素K1浓度的HPLC-APCI-MS测定方法,并评价维生素K1软胶囊的药动学特征及其与维生素K1片剂的人体生物等效性.方法:20 名男性健康受试者随机分成2 组,分别交叉口服受试制剂和参比制剂各 10 mg,采用HPLC-APCI-MS法测定人血浆中维生素K1的浓度,估算维生素K1的药动学参数及两种制剂的人体生物等效性.结果:血浆中维生素K1的最低定量限为 0.3 ng·mL-1,在0.3～1000 ng·mL-1范围内线性关系良好,批内及批间精密度RSD均小于15%.受试制剂与参比制剂的各主要药动学参数:tmax分别为(5.5±0.8)h和(5.0±0.8)h,cmax分别为(210.1±86.7)ng·mL-1和(194.8±60.6)ng·mL-1,t1/2分别为(8.8±1.7)h和(8.7±2.1)h,用梯形法计算AUC0～48分别为(1032.6±204.6)ng·h·mL-1和(1053.9±185.7)ng·h·mL-1.两种制剂的主要药动学参数cmax,AUC0～48经对数转换后进行方差分析及双单侧t检验,并计算90%置信区间,表明两种制剂生物等效,相对生物利用度为(99.7±21.2)%.结论:两种制剂生物等效.     

匹伐他汀钙片单、多剂量人体药动学评价

目的:建立LC-MS/MS法测定人血浆中匹伐他汀的浓度,研究其在中国健康受试者体内的单、多剂量药动学过程.方法:20名健康志愿者随机分为2组,每组10人(男女各半),分别口服低、中、高3个剂量(1,2,4 mg)进行单剂量药动学研究,2mg剂量组继续给药(每日1次,连续7 d),进行多剂量药动学研究.采用LC-MS/MS法测定血浆中匹伐他汀的浓度,并采用WinNonLin6.2计算药动学参数.结果:健康受试者单剂量口服1、2、4mg匹伐他汀钙片后的药动学参数:t1/2分别为(11.29±4.28)h、(13.52±5.65)h和(11.87±2.87)h;tmax分别为(0.78±0.32)h、(0.75±0.17)h和(0.93±0.31)h;Cmax分别为(15.80±7.34)ng·ml-1、(36.54±6.29)ng·ml-1和(61.32±15.09)ng·ml-1;AUC(0-48)分别为(36.46±21.86)ng·h·ml-1、(107.90±28.55)ng·h·ml-1和(187.76±62.62)ng·h·ml-1;AUC(0-∞)分别为(40.91±23.20)ng·h·ml-1、(112.97±29.08)ng·h·ml-1和(197.55±68.51)ng·h·ml-1.多剂量组口服2mg匹伐他汀后的药动学参数:t1/2为(13.07±2.16)h,tmax为(0.68±0.12)h,Cmax为(33.88±6.91)ng·ml-1,AUCss为(68.21±20.82)ng·h·ml-1,AUC(0-48)为(77.78±26.50)ng·h·ml-1,AUC(0-∞)为(82.59±26.58)ng·h·ml-1.匹伐他汀钙多次给药达稳态后,药动学参数tmax、t1/2与单次给药一致.结论:在1~4mg剂量范围内匹伐他汀的AUC(0-48)、AUC(0-∞)、Cmax均与剂量呈线性关系;匹伐他汀在连续多次给药后,无体内蓄积现象;匹伐他汀的体内过程在男女性别间无显著差异.     

兰索拉唑肠溶微丸胶囊人体生物等效性研究

目的:研究兰索拉唑肠溶微丸胶囊与兰索拉唑肠溶胶囊的人体生物等效性.方法:20名男性健康志愿者随机交叉单剂量口服兰索拉唑肠溶微丸胶囊(受试制剂)或兰索拉唑肠溶胶囊(参比制剂)30mg后,采用HPLC法测定血药浓度,用DAS软件计算药动学参数,并评价其生物等效性.结果:单剂量口服受试制剂兰索拉唑肠溶微丸胶囊和参比制剂兰索拉唑肠溶胶囊的主要药动学参数分别为:t1/2(1.93±0.58)、(2.21±0.84)h;tmax(1.7±0.4)、(1.7±0.4)h;Cmax(1 067.49±321.71)、(1 034.72±291.14)ng·ml-1;AUC0~12(3 655.16±1 635.82)、(3 571.70±1 434.56)ng·h·ml-1;AUC0~∞(3783.13±1 691.29)、(3 735.80±1 541.56)ng·h·ml-1.受试制剂的相对生物利用度为(106.72±13.53)%.结论:2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.

     

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.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.