盐酸多柔比星脂质体的制备及体外质量评价

目的：制备盐酸多柔比星脂质体并进行体外质量评价,以期实现自制脂质体质量与市售盐酸多柔比星脂质体注射液Doxil一致,并为其生物体内等效及产业化提供研究基础。方法：采用乙醇注入法结合硫酸铵梯度法制备盐酸多柔比星脂质体,以包封率为评价指标通过单因素筛选和正交试验优化制备工艺,以市售Doxil为参比制剂,对比最优工艺制得的脂质体与市售Doxil的微观结构、粒径大小及分布、Zeta电位、相变温度、包封率等理化指标,考察最优工艺制得的脂质体与市售Doxil在加速条件的体外释放及储存条件下稳定性情况。结果：自制盐酸多柔比星脂质体最优制备工艺为高速剪切速率13 000 r·min^-1,挤出3次,载药孵育温度65℃,载药孵育时间60 min,最优工艺制得的脂质体与市售Doxil外观均为椭圆形,平均粒径分别为（90.81±0.58） nm （n=3）和（89.05±0.66） nm （n=3）,分布较为均匀,Zeta电位分别为（-41.9±1.8） mV （n=3）和（-44.9±4.2） mV （n=3）,相变温度范围相同,包封率分别为98.0%和97.9%,体外释放较为一致,稳定性好。结论：采用最优工艺制备的盐酸多柔比星脂质体制备工艺可行,与市售Doxil相比,理化指标及体外释放无明显差异,自制脂质体体外质量良好,符合实验预期。     

胸腺五肽脂质体的研制

目的:制备胸腺五肽脂质体并进行质量评价。方法:采用复乳法制备胸腺五肽脂质体,以聚乳酸-羟基乙酸共聚物(PLGA)及卵磷脂为成球材料、以胸腺五肽为主药制备脂质体。以明胶浓度、PLGA浓度和卵磷脂浓度为考察因素,以包封率和载药量为考察指标设计L(934)正交试验优化基质处方并进行验证试验。通过测定优化处方所制脂质体粒径、包封率、体外累积释放百分率等评价脂质体质量。结果:优化基质处方为明胶、PLGA和卵磷脂浓度分别为100、200、100mg.mL-1。所制脂质体形态完整,平均粒径为(9.03±0.83)μm,载药量与包封率分别为(1.81±0.03)与(74.4±1.4),20d的累积释药百分率达90以上。结论:所制胸腺五肽脂质体工艺简单、重现性好,包封率和载药量高,具有显著的缓释作用。     

基于pH梯度载药技术的咪喹莫特脂质体的制备工艺研究

目的 根据咪喹莫特的理化性质,利用pH梯度主动载药技术制备脂质体,考察其性状、粒径、表面电荷及体外释药特征。方法 葡聚糖凝胶滤过法测定脂质体的包封率,以包封率与成型性为主要指标筛选制备方法,考察水化液的种类、pH值、离子强度及pH梯度载药、磷脂-胆固醇比例、脂药比、维生素E用量对包封率的影响;正交试验优化咪喹莫特脂质体的处方,考察脂质体样品在0~4℃下的稳定性。结果 按处方咪喹莫特50 mg、大豆卵磷脂400 mg、胆固醇130 mg、油酸10 mg、维生素E 5 mg、柠檬酸pH 2.5缓冲液5 mL,采用薄膜分散法工艺制备脂质体样品,并进行pH梯度主动载药,pH值调至7.0。制得的咪喹莫特脂质体呈白色均匀的混悬液,脂质体微粒圆整,分散性好,粒径（347±21）nm,包封率（81.2±1.9）%,Zeta电位（-12.19±1.7）mV。结论 pH梯度主动载药技术适于咪喹莫特脂质体的制备。     

左旋多巴脂质体的制备及影响因素

目的将左旋多巴作成脂质体以备鼻黏膜给药,并考察其影响因素。方法用硫酸铵梯度法制备左旋多巴脂质体,采用电子显微镜和粒度测定仪考察脂质体的形态、粒径及分布;采用SephadexG50葡聚糖凝胶柱分离,高效液相法测定左旋多巴脂质体的包封率,考察硫酸铵浓度、温度以及药脂比对包封率的影响。结果左旋多巴脂质体的平均粒径为185nm,药物包封率为90.3%;包封率随着硫酸铵的浓度和温度的升高而增加,随着药脂比的增大而降低。结论采用硫酸铵梯度法制备左旋多巴脂质体包封率高、粒径小且均匀,方法简便易行;硫酸铵浓度、温度以及药脂比是影响包封率的主要因素。     

盐酸莫西沙星脂质体的制备及包封率测定方法研究

目的：制备盐酸莫西沙星脂质体,建立盐酸莫西沙星脂质体包封率测定方法。方法：乙醇注入法制备盐酸莫西沙星脂质体,正交试验优选脂质体的最佳处方。采用葡聚糖凝胶柱法、超滤离心法分离脂质体与游离药物,并进行方法学考察,优选出测定盐酸莫西沙星脂质体包封率的方法。结果：盐酸莫西沙星脂质体的最佳处方为：卵磷脂与胆固醇比为 3：1,药脂比为 1：7,水合介质中聚山梨酯20的用量为1%,优化后的包封率为90.73%。葡聚糖凝胶柱法和超滤离心法都能将脂质体与游离药物分离,葡聚糖凝胶柱法的平均柱加样回收率为85.54%~88.15%,超滤离心法的平均加样回收率为94.40%~97.35%。结论：盐酸莫西沙星脂质体的制备工艺稳定,包封率较高。葡聚糖凝胶柱法不适于盐酸莫西沙星脂质体的包封率测定,超滤离心法可高效、准确、方便地测定盐酸莫西沙星脂质体包封率。     

依托泊苷隐形脂质体的制备及其质量评价

采用薄膜分散法制备空白脂质体,以PEG2000-DSPE为修饰材料、硫酸铵梯度法包封依托泊苷,减压冷冻干燥制得依托泊苷隐形脂质体。以包封率、载药量和6h累积释放率为指标综合评价,得优化处方为依托泊苷-大豆磷脂重量比1∶15,胆固醇-大豆磷脂重量比1∶6,硫酸铵浓度225mmol/L,包封温度70℃。平均包封率为(83.92±3.65)%,粒径(124.5±26.9)nm,ζ电位(-39.50±1.04)mV。     

他克莫司载药胶束的制备与制剂学性质

目的以聚乙二醇单甲醚-聚乳酸[methoxy poly(ethylene glycol)-poly(lactide),m PEG-PLA]嵌段共聚物为载体材料,制备他克莫司载药胶束,考察其制剂学性质。方法采用薄膜分散法制备他克莫司载药胶束。超速离心法测定他克莫司载药胶束的载药量和包封率。以载药量、包封率、粒径以及粒径分布为评价指标,采用单因素试验和正交试验优化他克莫司载药胶束制备处方。应用透射电镜、粒度测定仪和zeta电位分析仪对他克莫司载药胶束的形态、粒径和电位进行表征。结果在优化条件下制备的他克莫司载药胶束载药量为7.77%,包封率为84.31%,胶束粒子外观圆整且分散良好,平均粒径为23.20 nm,PDI为0.058,zeta电位为-0.831 m V。结论单因素试验联合正交试验可有效地优化他克莫司m PEG-PLA胶束处方和制备工艺。优化条件下制备的他克莫司载药胶束具有较高的载药量和包封率,粒径较小且分布均匀,24 h内稳定性良好。     

蓝萼甲素自组装纳米胶束的制备与性质研究

摘要目的制备蓝萼甲素自组装纳米胶束,并考察其性质。方法以三嵌段聚合物聚酯 聚乙二醇（PLGA PEG PLGA）为载体,采用溶剂蒸发法制备蓝萼甲素胶束,并通过正交实验筛选最佳制备工艺;采用芘荧光探针法测定临界胶束浓度（CMC）,透析法测载药胶束包封率和载药量,Zetasizer nano ZS仪测定其粒径和Zeta电位,透射电镜观察形态,并对其体外释放进行研究。结果胶束的CMC为2.5×10－3 mg•mL－1;平均粒径（62.49±0.60）nm,电位为（－25.4±0.4） mV;平均包封率（84.85±2.00）%;平均载药量（5.36±1.00）%;体外缓释约12 h,符合Higuchi方程。结论用三嵌段聚合物PLGA PEG PLGA可制备蓝萼甲素纳米胶束,因其缓释和纳米粒度特性而具有良好的应用前景。     

盐酸伊立替康脂质体的制备

目的结合脂质体这种新型给药载体的特征将盐酸伊利替康(Irinotecan,OPT-11)制备成脂质体以解决喜树碱类药物在生理条件下其结果中的内酯环易发生水解反应转变为羟酸盐形式,从而失去活性这个难问题.方法以包封率为主要评价指标,比较了传统的脂质体制备方法(薄膜分散法、乙醇注入法、反向蒸发法等)与主动载药方法-硫酸铵梯度法对伊立替康脂质体制备的影响.结果采用硫酸铵梯度法制备伊立替康脂质体可以获得较高的包封率、较大的药酯比.结论硫酸铵溶液的浓度、孵育时间和温度空白脂质体的粒径大小等是影响伊立替康脂质体包封率的主要因素.     

罗哌卡因-醋酸地塞米松PLGA微球的制备及体外释药特性研究

目的 制备罗哌卡因 醋酸地塞米松聚乳酸羟基乙酸共聚物（PLGA）微球（简称微球）并研究其体外释药特性。方法以PLGA为载体,采用W1/O/W2双重乳化 溶剂挥发法制备微球,研究实验过程中有机相PLGA浓度、外水相/有机相体积比、内水相体积、外水相聚乙烯醇（PVA）浓度几项因素变化对罗哌卡因 醋酸地塞米松PLGA微球粒径、表面形态﹑载药量﹑包封率和突释行为的影响。结果有机相PLGA浓度在制备微球的过程中是一个关键性因素。随着PLGA浓度增加,微球粒径增大,载药量﹑包封率明显提高,突释降低;外水相/有机相体积比增大,微球粒径增大, 载药量﹑包封率明显提高,微球表面更加光滑﹑微孔减少,突释降低;随着内水相体积增加使得微球表面的微孔明显增多,突释增加,载药量﹑包封率降低;当外水相PVA浓度由0.5%增加到2%,微球粒径变小,突释效应增加。通过优化条件制备的微球形状为球形,外观光滑圆整,粒径分布均匀,其中＞90%分布在20～70 μm。罗哌卡因载药量（7.48±0.33）%,包封率（70.97±2.36）%;醋酸地塞米松载药量（1.52±0.16）%,包封率（57.30±1.17）%。结论采用W1/O/W2双重乳化 溶剂挥发法成功制备罗哌卡因加醋酸地塞米松PLGA微球;以优化工艺制备的微球,在体外具有明显的缓释行为,释药曲线呈典型S形三阶段模式。     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.     

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.