洛伐他汀胶囊的人体相对生物利用度

健康受试者8名,随机分为2组,自身交叉单剂量po 100mg国产洛伐他汀胶囊与美国产洛伐他汀片后,用反相高效液相色谱法测定洛伐他汀血药浓度变化,进行相对生物利用度的研究.经3p87药物动力学程序处理,AUC分别是:194.75±42.29ng·ml~(-1)·h~(-1)与187.54±25.67ng·ml~(-1)·h~(-1),T_(max)分别为:2.625±0.354h与2.44±0.32h,C_(max)分别是:30.40±5.16ng/ml与30.99±5.98ng/ml.配对c检验结果表明:两者药-时曲线下面积、达峰时间及峰浓度均无显著性差异(P>0.05).双单侧t检验同样表明两者为生物等效制剂.洛伐他汀胶囊的相对生物利用度为(104.6±21.9)%.     

经皮给药后尼索地平在大鼠体内血药浓度的LC-MS法测定

建立了液相色谱-质谱法测定大鼠血浆中的尼索地平,并考察尼索地平微乳凝胶经皮给药后在大鼠体内的药动学.采用电喷雾离子源(ESI源),正离子检测,选择离子监测(SIM),监测离子对为m/z 411(尼索地平)和m/z 441(尼莫地平,内标).血浆中尼索地平在0.5～50 ng/ml浓度范围内线性关系良好,方法回收率为95％～102％,RSD≤5.8％.血浆中药物的提取回收率大于70％.采用雄性SD大鼠考察微乳凝胶经皮给药后的体内药动学行为并与口服混悬剂进行比较.含尼索地平20 mg的微乳凝胶经皮给药后的主要药动学参数分别为tmx (42.00±6.92)h,cmax (27.53±1.88) ng/ml,AUC0→72h(1736.31±106.59) ng·h·ml1,AUC0→∞(1999.66±119.26) ng·h·ml-1,MRT (44.02±0.77)h和t1/2 (7.61±0.70)h.     

自制复方洛伐他汀-烟酸缓释片及其人体药动学研究

目的 自制复方洛伐他汀-烟酸缓释片,并参照美国KOS公司的原研药对其处方工艺和人体药动学进行初步评价.方法 以释放度筛选烟酸缓释骨架组成,以溶出度试验确定洛伐他汀制剂组成,并按常规双层压片技术制备本品.分别以释放试验和释放度检测评价本品的体外释放行为;以高效液相色谱-质谱-质谱联用检测分析健康志愿者空腹及进食后的主要药动学参数.结果 本品以HPMC、PVP为烟酸缓释层骨架,以L-HPC为洛伐他汀常释层崩解剂,经双层压片技术成功制得.体外释放结果为:洛伐他汀30min溶出度≥80%,烟酸释放量2h为30%、4h为50%、8h为80%,f2值>50.人体药动学研究结果为:洛伐他汀单剂量进食组达蜂时间(Tmax)为(1.75±0.42)h、血药峰浓度(Cmax)为(2.12±0.67)ng/mL、半衰期(t1/2)为(11.21±7.60)h,单剂量空腹组Tmax为(1.90±0.74)h、Cmax为(1.49±0.60)ng/mL、t1/2为(12.2±7.65)h;烟酸单剂量进食组Tmax为(3.17±1.05)h、Cmax(317.3±407.1)ng/mL、t1/2为(10.39±5.26)h,单剂量空腹组Tmax为(1.63±0.48)h、Cmax为(247.3±312.9)ng/mL、t1/2为(11.54±5.01)h:结论本研究制得的产品表现为洛伐他汀速释、烟酸缓释的特性,体外释放曲线与原研药对照品一致.     

挤出造粒、气流包衣法制备包衣微粒剂．Ⅵ．氟尿嘧啶肠溶微粒的制备和药动学研究

用挤出造粒、气流包衣技术制备氟尿嘧啶肠溶微粒.体外试验表明,其在0.1mol/L盐酸中2h内不释放,在pH 6.8条件下30min释放大于96%.大鼠体内药物动力学研究表明口服氟尿嘧啶肠溶乳糖微粒后t1/2为(0.63±0.13)h,AUC0→6b为(1215.7±255.3)ng.h-1.ml-1,均优于氟尿嘧啶水溶液[t1/2为(0.35±0.03)h,AUC0→6b为(851.6±84.9)ng.h-1·ml-1].     

雷公藤内酯醇缓释微球的制备及体内外释放规律研究

目的:制备雷公藤内酯醇缓释微球,并考察其体内外释放规律。方法:采用液中干燥法制备雷公藤内酯醇缓释微球,以静止法研究其体外释放规律,以大鼠药动学实验研究其体内释药规律。结果:制备的缓释微球外观呈规则的球形,粒径分布均匀((38.2±1.7)μm),包封率为(74.7±3.2)%。雷公藤内酯醇缓释微球在体外恒速释放;在大鼠体内的Cmax为(114.7±31.90)ng.mL-1,tmax为(8.32±4.43)h,AUC为(1774282±1046152)ng.h.mL-1,MRT为(596±165)h;在体内外的相关系数为0.9553(P<0.01)。结论:本制备工艺可行;雷公藤内酯醇有制备成缓释注射微球的可行性。     

9-硝基喜树碱自微乳化给药系统研究

以Maisine 35-1为油相,Cremophor EL、Labrasol为表面活性剂,Transcutol P为助表面活性剂,制得9-硝基喜树碱(1)负电荷自微乳化制剂;在此基础上加入油胺作为正电荷剂可得1正电荷自微乳化制剂.用HPLC法测定大鼠体内1含量.结果表明含药的负、正电荷自微乳化制剂经水稀释10倍时,粒径分别为(24.7±7.9)和(25.0±8.3)nm,电位分别为-(4.8±0.5)和(2.4±0.9)mV.大鼠分别以6mg/kg的剂量灌胃给予1溶液和负、正电荷自微乳化制剂后,三者的Cmax分别为(93.8±72.8)、(176.4±93.4)和(128.9±49.1)ng/ml;AUC分别为(127.6±51.6)、(331.9±261.1)和(595.1±42.0)ng·ml-1·h;MRT分别为(1.6±0.9)、(1.2±0.6)和(4.3±2.4)h.正、负电荷自微乳化制剂的相对生物利用度分别是溶液的4.7和2.6倍,表明前者提高药物的口服吸收作用优于后者(P＜0.05).     

INS-SAIB原位微球的体外释放及对糖尿病大鼠的降糖作用

目的 制备胰岛素醋酸异丁酸蔗糖酯(INS-SAIB)原位微球,并研究其体外释药及其对糖尿病大鼠的降糖作用.方法 以醋酸异丁酸蔗糖酯为载体材料,采用注射器推动法制备INS-SAIB原位微球,使用Lowry法测定微球中胰岛素的含量,考察其体外释药特征;分别给予糖尿病大鼠sc 3个剂量INS-SAIB原位微球后,使用葡萄糖氧化酶法(GOD)测定血糖值,通过给药前后血糖水平的变化率(BGL),考察3个剂量INS-SAIB原位微球对糖尿病大鼠的缓释疗效.结果 所制INS-SAIB原位微球的平均粒径为98.86 μm;0.5 h累积释放度为34.65%,4～10 h的释放速度减慢,10 h的累积释放度为55.76%,12～24 h的累积释放度几乎不变;低、中、高剂量INS-SAIB原位微球分别在4、2、1 h时降至正常血糖范围,BGL分别为27.09%±1.97%、21.86%±0.75%、23.68%±2.12%,降血糖效果显著,且降糖效果持久;10 h低、中、高剂量组糖尿病大鼠的血糖仍维持在较低水平,BGL分别为32.02%±0.53%、32.15%±1.96%、21.70%±0.92%.结论 INS-SAIB原位微球的体外释放是药物扩散和载体材料溶蚀共同发挥的作用;INS-SAIB原位微球在糖尿病大鼠体内具明显的降糖效果和缓释特征.     

LC-MS法测定盐酸维拉帕米缓释微球在大鼠体内的药动学行为

目的制备盐酸维拉帕米缓释微球,应用液质联用法研究其在大鼠体内的药动学行为。方法应用喷雾干燥法制备维拉帕米缓释微球,分别灌胃给予大鼠维拉帕米缓释微球和市售普通片剂。大鼠血浆用甲醇萃取,以草酸艾司西酞普兰为内标物,采用液质联用法测定其血药质量浓度,采用PK-Solver软件计算其药动学参数。结果盐酸维拉帕米缓释微球在0.5、1、2、4、7、10、12和24 h的体外累积释放度分别为22.52%、32.35%、41.77%、55.32%、68.70%、72.10%、75.17%和78.25%。普通片剂的t_(max)、ρ_(max)、AUC0-∞分别为(1.3±0.4)μg·h·L~(-1)、(447.7±50.6)μg·h·L~(-1)和(1 482.6±81.2)μg·h·L~(-1),缓释微球的t_(max)、ρ_(max)、AUC0-∞分别为(4.1±1.6)μg·h·L~(-1)、(152.1±20.4)μg·h·L~(-1)和(1 478.1±89.7)μg·h·L~(-1)。结论以喷雾干燥法制备的盐酸维拉帕米(verapamil hydrochlorid,Ver)缓释微球体外释药性能良好,在体实验表明缓释微球能显著的降低给药后血药质量浓度的峰谷现象,延长药物作用时间并且具有良好的生物等效性。     

红景天苷单体与坤复康片大鼠口服药动学特征的比较

目的研究红景天苷单体和坤复康片在大鼠体内的药动学特征,探讨药物配伍对红景天苷单体在大鼠体内过程的影响。方法用LC/MS/MS法测定红景天苷和坤复康片在大鼠体内的血药浓度,估算两者的药动学参数。结果红景天苷和坤复康在大鼠体内主要药动学参数AUC0?t分别为(587.11±35.02)和(956.35±47.65)ng·h/ml;cmax分别为(85.81±15.66)和(143.86±46.91)ng/ml,两者有显著差异。结论坤复康片中的其他成分会影响红景天苷的吸收、分布和排泄。     

表柔比星在肿瘤患者体内的药物动力学

目的;研究表柔比星(Epi)在肿瘤患者体内的药物动力学.方法:11例肿瘤患者单次iv 60mg/m~2Epi,用HPLC测定Epi血药浓度,数据用3P87药物动力学程序进行模型拟合并计算药物动力学参数.结果:Epi的药-时曲线符合三室模型,其主要药物动力学参数分别为:T_(1/2p)=(0.052±0.018)h,T_(1/2(?))=(1.25±1.18)h,T_(1/2p)=(31.1±13.7)h,Vc=(23.9±11.2)ml,AUC=(2009±429)ng·h/ml,CL=(50.1±12.1)ml/h.结论:Epi在肿瘤患者体内分布迅速,消除缓慢.     

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.