吡硫醇丙酯亚微乳的制备及其性质考察

目的 制备吡硫醇丙酯亚微乳并考察其性质.方法 采用正交实验法优化吡硫醇丙酯亚微乳的最佳处方和工艺,并测定吡硫醇丙酯亚微乳的粒径、ζ电位和包封率.结果 确定了吡硫醇丙酯亚微乳的最佳处方工艺组合,即大豆磷脂与Pluronic F68质量比为2:1、剪切乳化时间为5 min、温度为60℃;制得的乳剂包封率为98.3%、平均粒径为133 nm、ζ电位为-27.5 mV.结论 所制吡硫醇丙酯亚微乳的粒度分布范围窄,包封率较高.     

注射用多烯紫杉醇亚微乳的制备

目的制备静脉注射用多烯紫杉醇亚微乳;对其理化性质和溶血性进行考察。方法采用高压匀质法制备多烯紫杉醇亚微乳。在最佳处方的基础上,考察制备工艺因素对乳剂的影响。考察亚微乳的粒径和ζ-电位以及制剂的含量。采用紫外分光光度法判断其有无溶血发生。结果亚微乳粒度分布均匀,药物含量质量分数达到90%以上;试管溶血试验阴性。结论多烯紫杉醇制备成静脉注射亚微乳后可以减少不良反应,提高稳定性。     

羟基喜树碱长循环亚微乳的制备及其在大鼠体内的药动学

以二硬脂酰磷脂酰乙醇胺-聚乙二醇(DSPE-PEG)2000共聚物、大豆磷脂S75、硬脂酰胺、泊洛沙姆188为辅料制备羟基喜树碱长循环亚微乳,所得长循环亚微乳平均粒径为(170.7±10.0)nm,ζ电位为(28.98±1.06)mV.同法制备了未PEG修饰的亚微乳.以喜树碱为内标,采用HPLC法测定血浆中的药物浓度.大鼠分别单剂量尾静脉注射给予羟基喜树碱长循环亚微乳、未PEG修饰的亚微乳和注射液.药动学研究表明,长循环亚微乳的t1/2β.和MRT均较未修饰亚微乳和注射液显著延长,提示PEG修饰的亚微乳在体内有较好的长循环作用.     

葛根素亚微乳的制备及表征

为降低葛根素的溶血副反应，制备葛根素亚微乳，进行处方及工艺优化，并考察其理化特征。结合磷脂复合物技术，采用相转变-超声乳化法制备葛根素亚微乳，以平均粒径、跨距、包封率和总评“归一值”为评价指标，采用中心优化设计考察乳化时间、搅拌转速、超声时间的影响，对结果进行多元线性和二项式拟合，利用效应面法优化最佳工艺条件。各指标二项式拟合方程均优于多元线性回归方程，确定最佳工艺条件: 乳化时间为15 min，搅拌转速为2 000 r·min^-1，超声时间为30 min，制备的葛根素静注亚微乳的平均粒径为228.23 nm，跨距0.628 4，包封率为84.32%，含量为9.98 mg·mL^-1，zeta电位为-29.03 mV。结果表明，相转变-超声乳化法制备的葛根素亚微乳粒径小，分布均匀，包封率高，稳定性好，理化指标稳定。     

处方因素对亚微乳物理稳定性的影响

目的 初步探讨亚微乳处方中乳化剂及油相因素对其物理稳定性的影响.方法 采用高速剪切分散和高压均质乳化工艺制备亚微乳,单因素试验法考察处方中乳化剂与油相对亚微乳物理稳定性的影响;以平均粒径、D50值、D99值及ζ电位为指标,考察不同处方中亚微乳灭菌前后的物理稳定性,并留样观察其长期稳定性.结果 泊洛沙姆188与中链油相互配伍不能得到性质稳定的亚微乳,且单独以泊洛沙姆188为乳化剂的各处方制剂长期放置后平均粒径明显增大;聚乙二醇硬脂酸酯( HS15)与各油相结合制得的亚微乳均较稳定,长期放置后各项指标基本不变;聚山梨酯80与大豆油-中链油(1∶1)混合油或大豆油配伍制成的亚微乳在灭菌后产生较大粒径的乳滴,而与中链油相配伍可制得粒径较小且均匀分散的体系;蛋磷脂E80单独作为亚微乳乳化剂,乳化效果欠佳.结论 大豆油、中链油及混合油与不同性质的乳化剂相互作用可共同影响亚微乳的粒径,但不同制剂的处方对亚微乳ζ电位无显著影响.     

尼莫地平亚微乳的制备及其性质考察

目的：制备尼莫地平亚微乳并对其性质进行考察。方法：本实验通过正交试验设计优选了尼莫地平亚微乳的最佳处方及制备工艺，并通过粒径测定、ζ电位的测定、包封率的测定和稳定性的考察等研究了尼莫地平亚微乳的性质。结果：尼莫地平亚微乳的最佳处方工艺组合为磷脂与泊洛沙姆188的比例为2：1（w：w），高速剪切乳化时间为5min，制备温度为70℃。所制备的乳剂包封率为97．9％，ζ电位为-30．6mV，平均粒径为137nm。稳定性考察表明该乳剂在常温及加速3个月条件下均较稳定。结论：本实验制备的尼莫地平亚微乳粒度分布范围窄，稳定性较好，包封率较高。     

普罗布考亚微乳剂的制备

以中链甘油三酯为油相,蛋黄卵磷脂和泊洛沙姆188为乳化剂,采用高压乳匀法制备普罗布考亚微乳剂.以平均粒径、多分散系数(PDI)、ζ电位和稳定性等评价指标优化了处方.按优化条件制得的普罗布考亚微乳稳定性良好,平均粒径(168.8±1.5) nm,ζ电位(50.1±1.7) mV,载药量为(4.2±1.6)mg/ml.     

葛根素自微乳的制备及其质量控制

目的制备葛根素自微乳给药系统并建立其质量评价方法。方法以乳化剂OP-10、CremophorRH40、Transcutol P制备葛根素自微乳给药系统,考察其外观、Zeta电位、粒径分布及稳定性;采用高效液相色谱法建立葛根素自微乳的质量评价方法。结果所得自微乳稳定性良好,平均粒径为32．31nm,电动电势为-19．98mV（／Z=3）。葛根素的HPLC分析线性范围为0．213—3．195μg;平均回收率为100．25％（n=9）,RSD=0．49％。结论本制剂制备工艺简便,质量稳定可控,符合良好的身微乳制剂的要求。     

苯丁酸氮芥钠亚微乳储存后的粒径变化及释药行为

目的以大豆油为药物载体及乳滴基本成分,大豆磷脂为乳化剂,制备苯丁酸氮芥钠亚微乳,考察水相pH,油酸,吐温-80等因素对药物包封率、粒径稳定性的影响,并考察药物的释放行为。方法采用高速剪切法制备粗乳,磷酸调节粗乳外水相pH值,高压均质法制备亚微乳,密封高温高压灭菌得最终产品。激光动态光散射法测定乳滴粒径,酸度计测定乳剂的pH,考察两个时间段的储存期后的乳滴粒径、ζ电位和乳剂pH的变化。低温高速离心分离油水两相,高效液相色谱-紫外分光光度法测定水相及全乳的药物含量并得到包封率,正渗透膜透析法考察乳剂中苯丁酸氮芥钠在pH7.4的磷酸缓冲盐中的释放行为并对释放曲线进行拟合。结果粗乳pH值越低,苯丁酸氮芥钠在最终产品乳滴中的包封率越高,油酸和Tween-80有助于包封率和ζ电位绝对值的提高。所得乳剂在储存30、60 d后,均出现pH降低的现象。油酸防止了粒径的增长和ζ电位绝对值的降低,Tween-80未有此作用。药物有明显的突释相,突释相过后呈现缓释相,包封率越低突释率越高。药物的释放符合Freundlich方程。结论调节合适的pH,选用合适的助乳化剂,有助于得到包封率较高、稳定性较好、呈现特定缓释行为的苯丁酸氮芥钠乳剂。     

辅酶Q_(10)亚微乳的制备及理化性质考察

目的:制备辅酶Q10亚微乳,并考察其稳定性及理化性质。方法:设计正交试验优选辅酶Q10亚微乳的处方及制备工艺并制备乳剂,以高效液相色谱法测定其含量及包封率,考察其粒径、ζ电位、pH值及稳定性等。结果:辅酶Q10亚微乳的最佳处方工艺为大豆油∶中碳链甘油三酸酯=1∶2,大豆磷脂∶泊洛沙姆188=3∶1,高速剪切乳化时间10min,制备温度60℃。所制备的乳剂包封率3批样品平均值为98.07%,ζ电位为—28.4mV,平均粒径为168nm。该制剂贮存时应避免光照和冻融,在4℃条件下稳定性较好。结论:所制备的辅酶Q10亚微乳满足静脉注射用制剂要求。     

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.     

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.