利多卡因——卵磷脂微乳处方的初步研究

目的 :以卵磷脂微乳为载体 ,制备利多卡因透皮给药系统。方法 :伪三元相图考察油包水型微乳形成区域 ;测定微乳黏度 ,正交分析法筛选微乳处方 ;紫外分光光度法直接测定微乳中盐酸利多卡因浓度。结果 :助表面活性剂的种类和Km(表面活性剂 /助表面活性剂用量比 )对微乳形成区域有显著性影响 ,正丙醇和异丙醇所形成的微乳区较大 ;低纯卵磷脂微乳形成区域较高纯卵磷脂大 ;醇的种类对微乳的黏度均有显著的影响 ,Km 对微乳的黏度有较大影响。选定紫外检测波长为 2 6 2nm ,盐酸利多卡因浓度在 0 .0 2～ 0 .5mg/mL范围内线性关系良好 (R =0 .9999)。平均回收率 ( 10 0 .17± 0 .16 ) %。日内差与日间差分别为 0 0 137±0 0 12 1,0 0 119± 0 0 115。结论 :选择混合表面活性剂利于制备微乳 ,醇的种类与用量对于利多卡因透皮微乳体系处方的选择具有重要意义。     

油-吐温-醇-水体系伪三元相图在自微乳化制剂研究中的应用

分别以油酸乙酯、亚油酸乙酯、乙酸乙酯为油相,吐温-80为表面活性剂,无水乙醇、正丙醇、异丙醇、乙二醇、1,2-丙二醇、丙三醇、正丁醇和聚乙二醇400为助表面活性剂,在37℃水浴中,用水滴定上述三组分不同配比的混合物,绘制油-吐温-80-醇-水体系伪三元相图,并对自微乳化系统进行研究.结果表明,相同条件下以乙酸乙酯为油相的体系,相图中自微乳区面积大于以油酸乙酯和亚油酸乙酯为油相的体系.随着体系中吐温-80-醇重量比(Km)减小,形成的自微乳区面积减小;若表面活性剂黏度较大,则以油酸乙酯和亚油酸乙酯为油相的体系相图中可出现凝胶区,随Km减小,凝胶区减小直至消失.     

糠酸莫米松微乳的制备工艺研究

目的研究糠酸莫米松微乳的处方及制备工艺。方法通过滴加法绘制假三元相图,考察各因素对微乳形成的影响,以微乳区面积、最大载油量为指标,考察了油相、水相、表面活性剂、助表面活性剂、温度等对表面活性剂体系相行为的影响。结果初步确定微乳的制备工艺:精密称取处方量的辛癸酸甘油酯、RH 40/1,2-丙二醇(Km=3)的混合表面活性剂、处方量的糠酸莫米松组成油相,在60℃下磁力搅拌至油相混合均匀且澄清加入处方量的水溶液(含苯扎氯铵为0.01%,枸橼酸0.09%,枸橼酸钠0.07%),磁力搅拌10 min,形成澄清透明、带蓝色乳光的微乳。结论优选的处方及制备工艺用于制备糠酸莫米松微乳,重复性好,性质稳定。     

水包油型微乳形成因素的考察

目的考察影响O/W型微乳形成的主要因素。方法选用丁酸乙酯、油酸乙酯和豆油作为油相 ,Tween 80、Tween 2 0和Labrasol作为表面活性剂 ,乙醇、1,2 -丙二醇和正丁醇为助表面活性剂 ,通过滴加法绘制假三元相图 ,以O/W型微乳区大小为指标考察各因素对微乳形成的影响。结果油相、表面活性剂、助表面活性剂、表面活性剂与助表面活性剂的质量比、离子强度、添加剂和温度对微乳的形成均有一定影响。结论O/W型微乳能够作为药用载体。     

不同助表面活性剂对o/w型微乳形成的影响

在微乳配方开发过程中,通常选用短链醇作为助表面活性剂,然而有些药物在这些助表面活性剂中的溶解度或相容性并不理想.因此,选用非醇类物质(Plurol(R) Oleique CC 497、CapyrolTM 90或Transcutol(R))为助表面活性剂,并以Labrasol(R)为表面活性剂,Labrafil(R) M 1944为油相,分别绘制了空白微乳的伪三元相图.结果表明,这些助表面活性剂的种类和表面活性剂/助表面活性剂比例(Km)对o/w型微乳的形成有影响.     

氢溴酸东莨菪碱微乳的组成对其制备的影响

通过绘制伪三元相图考察体系各组分对空白微乳形成及其粒径和黏度的影响.结果表明,以Cremophor RH-40为表面活性剂,无水乙醇为助表面活性剂,Labrafil M 1944 CS为油相可得稳定的微乳体系.该体系中水溶性药物氢溴酸东莨菪碱的加入量对微乳的粒径和黏度无显著影响.     

非离子表面活性剂微乳的制备及抗菌性考察

目的:制备一种药用非离子表面活性剂空白微乳,并评价其抗菌性.方法:采用拟三元相图考察表面活性剂、助表面活性剂及其质量比、添加剂、温度等对微乳区的影响;高速离心法和37℃恒温1个月考察微乳稳定性;抗菌试验考察其抗菌能力.结果:油酸乙酯为油相、聚氧乙烯蓖麻油为表面活性剂、异丙醇为助表面活性剂的微乳区范围较大,可无限稀释;稳定性试验未见相分离;水相中的添加剂及温度的变化对微乳区范围无显著性影响;微乳均能有效杀灭绿脓杆菌、金黄色葡萄球菌、大肠杆菌、白色念珠菌,其中作用8 h后绿脓杆菌杀灭完全.结论:本品能自身抗菌,有可能成为适合眼用、注射等的潜在给药载体.     

油酸微乳对利多卡因透皮吸收的影响

目的研究油酸微乳对利多卡因透皮吸收的影响。方法在制备相图的基础上，考察了微乳的组分对微乳形成的影响。选择适当的表面活性剂/助表面活性剂比例，制备利多卡因的油酸微乳处方，考察微乳、乳剂、胶束和饱和水溶液在透皮吸收方面的差异。结果以Labrasol为表面活性剂，吐温80为助表面活性剂所得油酸微乳的区域较大，微乳对利多卡因有明显的促透作用，透皮速率依次为微乳＞乳剂＞饱和水溶液＞胶束。结论油酸微乳可促进利多卡因的透皮吸收。     

油包水型药用微乳的处方筛选及质量评价

目的:筛选水溶性药物油包水型药用微乳的处方及质量评价。方法:选用Volp-5为表面活性剂,短链醇类化合物作助表面活性剂及不同的油相,采用伪三元相图法筛选处方组成及其质量比,考察组分、温度、添加剂等对微乳区的影响以及微乳的稳定性。结果:以适当的基质配比制得了稳定的微乳。油包水型药用微乳处方为Volp-5/乙醇/辛酸癸酸甘油酯/水(3∶2∶2∶4)。结论:油包水型微乳可作为水溶性药物新剂型载体,其质量稳定,易于制备。     

利多卡因纳米乳的制备及质量控制

目的制备利多卡因纳米乳并建立其质量控制的方法.方法伪三元相图法结合origin 7.0软件分析确定制备5%利多卡因纳米乳的最佳Km值(表面活性剂/助表面活性剂)及各组分的比例;对利多卡因纳米乳的外观及稳定性进行考察;马尔文Zeta粒径分析仪测定利多卡因纳米乳粒径大小及分布范围;透射电镜观察利多卡因纳米乳的形态及体系类型;HPLC法对利多卡因纳米乳进行质量控制考察.结果Km=3时利多卡因纳米乳形成区域的面积值最大,利多卡因纳米乳的平均粒径为36.4 nm,其中98%的粒径范围介于17.1～57.5 nm之间,2%介于77.9～261.3 nm之间;其分布体系为大小不均的球形多分散体系;利多卡因进药量与色谱峰面积在10～200 mg·L-1范围内线性关系良好(r=0.999 4),平均回收率为99.45%,RSD为1.08%.结论伪三元相图法结合origin 7.0软件分析并确定利多卡因纳米乳各组分比例的方法简便、准确;马尔文粒径测定结合透射电镜观察测定利多卡因纳米乳的粒径、分布、形态及体系类型的方法较为全面;利多卡因纳米乳样品的处理和HPLC测定方法简便、快速、准确,可作为利多卡因纳米乳的质量控制考察.     

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.     

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.     

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.     

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.