苦参碱缓释微球的制备及体外释药研究

目的：制备苦参碱缓释微球并考察其体外释放度。方法：采用正交试验设计,优选处方,乳化-固化法制备苦参碱微球,对其包封率、形态、粒径及体外释药性质进行了研究。结果：苦参碱白蛋白微球平均粒径为12.64 μm,大小均匀。平均包封率为79.60%±0.98%。体外释放符合零级方程,t_1/2为46.8 h。结论：苦参碱缓释微球制备方法简便,缓释效果好。     

斑蝥素白蛋白微球制备工艺的优化

目的优化斑蝥素白蛋白微球的制备工艺,并对其形态学性质、载药量进行考察.方法以加热固化法制备微球,以均匀设计考察影响因素.结果微球平均粒径为(0.91±0.16)μm,载药量为(15.32±1.15)%.结论优化后工艺较合理,所制得微球形态圆整、均匀,载药量较高.     

栓塞颌面血管瘤动脉的平阳霉素白蛋白微球的制备

目的　制备平阳霉素白蛋白微球 ,提高平阳霉素抑制血管瘤的作用。方法　以化学交联法在单因素考察的基础上进行均匀试验设计 ,筛选出栓塞血管瘤动脉的平阳霉素白蛋白微球的最佳制备工艺 ,考察了微球的形态和粒度分布及体外释药特性。结果　化学交联法制得的微球表面圆整、光滑 ,平均粒径为 83.6± 10 .5 μm ,药物平均包封率为 34.3% ;载药量为4 0 .2 % ;释药特性可用Higuichi和单指数方程描述。结论　以化学交联法制备的平阳霉素白蛋白微球粒径符合栓塞要求 ,体外具有明显缓释效果。     

牛血清白蛋白阳离子微球的制备及体外评价

目的 制备牛血清白蛋白(BSA)口服阳离子微球,考察天然阳离子物质壳聚糖(CHS)的加入对蛋白微球的粒径、电动电势、包封率、载药量及体外释放情况的影响。方法 以乳酸/羟基乙酸共聚物(PLGA)和壳聚糖(CHS)为载体材料,采用W/O/W复乳-溶剂挥发法制备牛血清白蛋白乳酸/羟基乙酸共聚物-壳聚糖(PLGA/CHS)阳离子微球。通过正交设计优化制备工艺,确定最佳处方。建立准确而简便的蛋白含量测定方法,并对微球进行体外评价。结果 最佳处方为：BSA浓度为150 g·L^-1、PLGA浓度为8%、外水相体积为80 mL、壳聚糖浓度为0.2%。制得的微球形态圆整,平均粒径为(6.9±5.5)μm,为表面荷正电的阳离子微球[ζ电势=(10.0±0.6)mV],包封率为(75.4±4.6)%,载药量为(9.3±0.2)%。体外释放结果表明,在模拟胃液和模拟肠液中,壳聚糖的加入均能减少突释,延缓药物的释放。结论 与PLGA微球相比,制得的PLGA/CHS阳离子微球表面带正电,具有较高的包封率和载药量,可以延缓药物释放,同时减少突释现象。     

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。     

延胡索乙素胃漂浮微球的体外漂浮及释药特征评价

目的 制备延胡索乙素(tetrahydropalmatine,THP)胃漂浮微球,考察THP胃漂浮微球在不同条件下的体外漂浮性能与释药特征。方法 采用乳化溶剂挥发法制备THP胃漂浮微球,模拟胃肠道环境,通过直接观察法考察THP胃漂浮微球在0.1 mol·L^-1盐酸溶液、pH 3.0 PBS、pH 4.5醋酸缓冲液、pH 6.8 PBS释放介质,50,100,150 r·min^-1转速条件下的漂浮性能;采用转篮法考察THP胃漂浮微球在上述释放条件下的体外释放特征;以罗通定片为参比制剂,比较两者在模拟胃酸环境的体外释放特征;采用常见的动力学模型拟合延胡索乙素胃漂浮微球的释药曲线。结果 THP胃漂浮微球在不同介质中均能立即起漂,持漂12 h,漂浮率为100%;在4种释放介质中12 h累积释放度分别为(90.55±4.65)%,(81.48±5.92)%,(66.24±3.00)%,(51.93±2.35)%;在3种转速下,12 h累积释放度分别为(84.26±3.22)%,(90.55±4.65)%,(94.70±2.15)%。在模拟胃酸环境(0.1 mol·L^-1盐酸溶液)下,罗通定片0.5 h累积释放度为(78.31±11.01)%,2 h基本释放完全,而THP胃漂浮微球12 h内释药速度平稳而缓慢,无突释现象,且释药完全。结论 该研究制备的THP胃漂浮微球体外漂浮性能较好,具有较好的缓释效果,其体外释放行为符合Higuchi方程。     

bFGF-PLGA缓释微球及其体外释药性能研究

目的以bFGF为缓释药物、PLGA为药物载体制备bFGF-PLGA缓释微球,观察微球表面形态,检测微球物理性能和体外释药行为。方法采用W1/O/W2复乳溶剂挥发法制作微球;通过扫描电镜观察微球的表面形态结构;利用ELISA法测试微球中药物的载药量和包封率,并对微球中药物的体外释放行为进行研究。结果微球表面圆滑均匀,平均粒径(0.75±0.08)μm,载药量[(59.9±1.9)×10-3]%,包封率为(79.9±2.8)%;在为期45 d的体外释放试验中,bFGF累积释放率达到80%。结论bFGF-PLGA微球能够稳定地在较长时间释放药物bFGF,验证了PL-GA微球作为bFGF控制释放载体的可行性。     

磁性免疫微球在人血清白蛋白纯化中的应用

目的为了快速地从人血清中提纯人血清白蛋白，利用磁性免疫微球作为提取手段，再用间接酶联免疫法测定人血清白蛋白的回收率。方法将经过羧基修饰的聚苯乙烯微球作为载体，用EDC(碳化亚胺)活化微球表面的羧基，再将兔抗人血清白蛋白抗体包被于微球上，这种微球-抗体复合物能特异性地捕获人血清白蛋白，磁分离复合物后，通过将兔抗人血清白蛋白抗体作为捕获抗体，将酶联羊抗人血清白蛋白抗体作为检测抗体，建立起间接酶联免疫法，用于检测人血清中和磁性免疫微球上吸附人血清白蛋白的浓度，得到微球从人血清中提纯人血清白蛋白的回收率。结果第1次提纯的回收率为(86±4)%，重复利用微球2次，回收率分别为(69.0±0.6)%和(40.8±0.8)%，而提纯的人血清白蛋白的纯度为90%。结论以上结果表明，免疫磁性微球提纯人血清白蛋白的实验是有效的，为工业上大规模提纯人血清白蛋白提供了一条新的思路。     

阿苯达唑-聚乙二醇6000固体分散体壳聚糖微球的制备与药剂学性质研究

目的:制备阿苯达唑-聚乙二醇6000(PEG)固体分散体壳聚糖微球并评价其性质。方法:以阿苯达唑-PEG固体分散体(ASD)为主体,壳聚糖为载体,采用乳化交联法制备ASD壳聚糖微球;采用电镜、红外光谱、X衍射分析法等对微球进行表征并考察其药剂学性质;动态透析法研究微球的体外释放特性。结果:所制得微球形态圆整,粒径分布均匀,平均粒径约(210±3.8)μm,载药量(6.42±0.32)%,包封率(57.86±0.74)%;红外光谱、X衍射分析法证明药物成功包载于微球中;微球在醋酸盐溶液(pH3.5)介质中的释放情况遵循Higuchi方程,可持续释放400h以上。结论:本法制备微球工艺稳定,所制微球具有显著的缓释效果。     

羟基喜树碱微球的制备及其小鼠体内分布研究

目的:制备肺靶向性羟基喜树碱(HCPT)微球,评价其体外释药特性及其在小鼠体内的肺靶向性。方法:以聚乳酸为主要辅料,采用溶剂挥发法制备微球,考察其粒径、包封率、载药量,比较微球及原料药的体外释药性;取12只小鼠分别尾静脉注射HCPT微球及原料药,30min后分别测定血浆及各组织的药物浓度并计算相对分布率。结果:所制微球粒径在7～30μm者达81.6%,平均粒径为(14.2±3.1)μm,包封率为72.36%,载药量为(40.6±3.6)%,微球及原料药体外释药参数T50分别为85、18min。微球给药组在肺中的药物浓度最高(32.2±2.48)μg.mL-1,相对分布率58.1%;原料药给药组在血浆中的药物浓度最高(13.52±2.58)μg.mL-1,相对分布率25.24%。结论:所制HCPT微球具有明显的缓释性及肺靶向性。     

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.

     

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.