壳聚糖-阿司匹林缓释微囊的制备工艺及体外溶出实验

以壳聚糖和阿拉伯胶为囊材,探讨将阿司匹林微囊化的制备工艺及缓释测定。以微囊的药物包封率为制备工艺优化指标,利用复凝聚法,通过正交实验得出微囊的最佳制备工艺条件:壳聚糖浓度为0.6%、成囊pH为4.5、搅拌速度为200r.m in-1、成囊温度为60℃为最佳工艺条件。以最佳制备工艺条件制备含药微囊,重现性好,工艺稳定,同时体外溶出实验表明,该微囊具有较好的缓释作用。     

萘普生缓释微囊的制备及其体外释药研究

目的 对以壳聚糖和海藻酸钠为囊材,通过复凝聚法将萘普生微囊化的制备工艺和体外释药进行研究.方法 以微囊的药物包封率为制备工艺优化指标,得出成囊的最佳制备工艺条件.结果 最佳工艺条件为:搅拌速度500 r·min-1,pH4.0,壳聚糖浓度3%,反应温度50℃.结论 以最佳制备工艺条件制备了可生物相容,自然降解无毒的载药微囊,重现性好,工艺稳定,同时体外溶出实验表明,该微囊具有较好的缓释作用.     

复凝聚法制备槲皮素微囊的工艺

目的:优选以明胶和阿拉伯胶为囊材制备槲皮素微囊的最佳工艺条件。方法:采用复凝聚法,以槲皮素为囊芯物,用明胶和阿拉伯胶作囊材,取pH、囊材浓度及搅拌速度3个为考察因素,用正交试验探讨制备槲皮素微囊的最佳条件。结果:当pH为4.0,囊材为3%,搅拌速度为150 r.min-1时为最佳工艺条件。结论:本法工艺简便、稳定,具有应用前景。     

正交实验设计优化岩白菜素微囊的制备工艺

目的优化岩白菜素微囊的制备工艺,并对制备的岩白菜素微囊进行质量评价。方法以明胶为囊材,单凝聚法制备岩白菜素微囊,通过正交实验设计优化其制备工艺,并对包封率、载药量、平均粒径、体外溶出率进行研究。结果明胶制备岩白菜素微囊的最佳工艺条件为:明胶质量分数为6%,囊心囊材质量比为1∶2,搅拌速度为750r·min^-1。此最佳工艺制备的岩白菜素微囊包封率为75.90%,载药量为23.09%,体外溶出度测定30min为28.6%,12h累计释放达到90%以上。结论以最佳工艺条件制备岩白菜素微囊工艺稳定,包封率高,同时体外释放实验表明,该微囊具有较好的缓释作用。     

含ZnS的壳聚糖-阿拉伯胶含药微囊的制备及研究

目的本文以壳聚糖和阿拉伯胶为囊材,利用复凝聚法制备包裹非甾体抗炎药物布洛芬的微囊,引入ZnS纳米,增强其缓控释性能。方法将含乙酸锌的壳聚糖溶液与含Na2S的阿拉伯胶溶液混合,以布洛芬为模型药物,通过复凝聚法制备包裹非甾体抗炎药物布洛芬的复合微囊,以微囊的药物包封率与载药量为制备工艺优化指标,通过L9（34）正交实验得出微囊的最佳制备工艺条件。同时用转篮法在肠液条件下进行体外溶出的测定。结果壳聚糖浓度为0.2%、成囊pH为4.5、成囊温度为45℃、搅拌速度为200 rpm。交联剂戊二醛用量0.6mL,乙酸锌0.05M,硫化钠0.05M为最佳工艺。引入纳米ZnS的微囊比未引入纳米ZnS的微囊及市售的片剂具有更好的缓控释性能。结论引入纳米ZnS离子,并以最佳制备工艺条件制备含药微囊,工艺稳定,具有良好的缓控释作用。     

京尼平苷微囊的制备及体外评价

目的:优选制备京尼平苷微囊的工艺条件.方法:明胶为材料,采用单凝聚法,以包封率为评价指标,利用均匀设计法优选最佳的微囊制备条件.结果:囊心囊材比为1∶12,温度45℃,转速为500 r·min-1.结论:微囊制备工艺稳定、粒径分布及溶出符合要求.     

喷雾干燥法制备莪术油微囊

目的 研究喷雾干燥法制备莪术油微囊的最佳处方及工艺。方法 以阿拉伯胶和麦芽糊精为囊材,喷雾干燥法制备莪术油微囊,以包封率为考察指标,探讨囊材配比、助乳化剂用量、固形物含量、微囊心材比等对微囊化的影响,并对喷雾干燥工艺进行正交试验考察。结果 阿拉伯胶和麦芽糊精的最佳配比为4：1,司盘-80 1 mL,固形物含量为40 %,微囊心材比为4 mL：10 g;喷雾干燥工艺条件为：进风温度160 ℃,进料速度2.5 mL&;#8226;min-1,吸气功率100%,制得的微囊囊形较好,平均粒径为5.2 μm,包封率可达到94.2 %,且微囊稳定性好。结论 根据该实验条件制得的微囊囊形圆整、表面致密,包封率较高,稳定性好。     

萘普生微囊的制备及其质量考察

目的:制备萘普生微囊并考察其制剂质量。方法:以明胶和阿拉伯胶为囊材,采用复凝聚法将萘普生制成微囊;以阿拉伯胶浓度(A)、萘普生与阿拉伯胶的质量比例(B)和成囊温度(C)为考察因素,包封率为指标设计正交试验优化成囊的最佳制备工艺,并对优化工艺所制得微囊的粒径、包封率、载药量、体外释放性进行考察。结果:最佳工艺条件为A2%、B1:1、C50℃;所制微囊的平均囊径48.92μm,包封率(77.03±1.43)%,载药量(35.31±1.02)%,微囊在48h时体外累积溶出百分率达到91.32%。结论:所制萘普生微囊工艺重现性好、稳定,并具有良好的缓释作用。     

正交法研究双嘧达莫微囊的制备工艺

目的 :研究双嘧达莫微囊的制备工艺。方法 :用正交设计法对双嘧达莫微囊的制备工艺进行研究。结果 :用单凝聚法制备双嘧达莫微囊 ,其包裹率与囊心囊材比有显著性差异 (P<0.05) ,而搅拌速度能影响微囊的粒径 ,当囊心囊材比为1∶4、成囊温度50℃、搅拌速度为400r/min时 ,包裹率最高 ,囊径最小。结论 :该法工艺简单、可靠     

原位聚合法制备脲醛树脂微囊的处方工艺研究

目的 确定制备脲醛树脂微囊的最佳处方和工艺,特别是包括抗微囊粘连效果最佳的抗黏剂和添加剂.方法 采用原位聚合一步法制备微囊,考察系统稳定剂种类及用量、多种抗粘剂及添加剂对成囊过程及囊粒粒径的影响.结果 以1.5％PVA作为系统稳定剂,在pH值为3.5、搅拌速度为700r/min的工艺条件下,制备的微囊粒径均匀、不粘连.反应结束后调节系统pH值为7,加入固化剂间苯二酚和增稠剂黄原胶,具有良好抗粘连效果.结论 系统稳定剂的作用是使芯材形成稳定油滴,促使囊材包覆其表面上,最佳的系统稳定剂可降低囊材自身成核的几率.     

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.     

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.     

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.