氟比洛芬自乳化给药系统的制备及体外溶出度考察

目的：制备氟比洛芬自乳化给药系统（SEDDS）以提高药物的溶出度。方法：通过绘制假三元相图和体外自乳化效率的评价确定最优处方；以氟比洛芬片为参比制剂测定SEDDS的溶出度。结果：最优SEDDS处方中的油相为油酸乙酯，乳化剂为聚山梨醇酯80，助乳化剂为PEG400，其比例N50．0：35．0：15．0，药物为辅料总量的5．0％。结论：氟比洛芬SEDDS与片剂相比，药物的溶出度有显著提高。     

维生素E烟酸酯自乳化制剂处方研究

目的研究维生素E烟酸酯(简称VEN)自乳化制剂,探求其最佳处方配比。方法通过溶解度实验、正交筛选和假三角相图的绘制,以形成自乳化区域的大小、溶出度和所得乳滴粒径的大小为指标,对VEN自乳化制剂中的油相、乳化剂及助乳化剂的组成、用量进行筛选,找出最佳的搭配和处方配比。结果在VEN自乳化制剂处方中,以油酸乙酯为油相,聚氧乙烯蓖麻油(EL20)为乳化剂,乙二醇单乙基醚(transcutol)为助乳化剂时,可以获得较好的乳化效果。结论VEN自乳化制剂的最佳处方比例为m(VEN)∶m(油酸乙酯)∶m(EL20)∶m(transcuto1)=1∶0.75∶1.35∶0.9。     

罗红霉素自乳化制剂的制备及体外评价

目的制备罗红霉素自乳化制剂,并初步探讨其体外质量评价。方法通过测定药物在不同油相中的溶解度,确定油相与各种乳化剂(助乳化剂)的配伍对自乳化效率的影响;通过绘制伪三相图,筛选罗红霉素自乳化制剂的最佳处方;考察该制剂水稀释液的微乳外观、粒径和乳化时间。结果自乳化制剂处方为罗红霉素:肉豆蔻酸异丙酯:Tween80(甘油)为3∶3∶4,该制剂稀释50倍后仍为澄清透明液体,粒径约75nm,呈正态分布,乳化时间约10min。结论罗红霉素自乳化制剂制备简单,质量稳定,能显著提高药物的溶解度。     

十一酸睾酮自微乳化制剂的处方研究

目的 制备十一酸睾酮(TU)自微乳化制剂。方法 通过伪三元相图绘制和自乳化效率的评价筛选TU自微乳化制剂处方,用HPLC测定药物的含量,考察制剂经高温和光照的影响因素试验后的质量。结果 以辛癸酸甘油酯为油相、Cremophor EL /Tween 85(1∶4)为混合乳化剂、油相与乳化剂重量比1∶1作为TU自乳化制剂介质的处方,在不同介质能迅速形成自微乳液。经高温10 d放置,TU自乳化制剂的质量未发生变化,光照10 d后药物含量略有下降。结论 制备了不含助乳化剂的TU自微乳化制剂,适合于进一步制成软胶囊。     

水飞蓟宾磷脂复合物自微乳给药系统研究

目的研制水飞蓟宾（SLB）磷脂复合物自微乳化胶囊并对其进行体外评价。方法通过单因素考察结合正交设计将SLB制成磷脂复合物,测定了该复合物的溶解度和油水分配系数,进一步制成自微乳给药系统。结果 SLB磷脂复合物的最佳工艺条件为,反应温度50℃,反应时间2 h,比例1∶2。按此最佳工艺条件制备SLB磷脂复合物,复合率为100%,其溶解度和油水分配系数分别为126.3μg.mL-1,166.64,其最佳自微乳给药系统（PMC）组成及比例为,复合物∶油酸乙酯∶吐温80∶丙二醇=12∶30∶45∶13。按最佳处方制备的SLB磷脂复合物-PMC在人工胃液中36 min内累积溶出百分率已达到80%。结论将水飞蓟宾制成磷脂复合物自微乳化胶囊能显著提高其体外溶出度。     

胰岛素磷脂复合物自微乳传递系统的制备

目的 构建胰岛素磷脂复合物自微乳传递系统(ISC-SNEDDS).方法 利用冻干法制备胰岛素磷脂复合物(ISC),根据其溶解性选择油相,确定复合物中胰岛素(INS)与磷脂(SPC)的最佳质量比;利用假三相图法,通过乳化后的外观和粒径筛选最优空白自微乳处方并制备载药自微乳制剂.结果 制成磷脂复合物后,胰岛素在油酸乙酯中的溶解度显著增加;自微乳的最优处方为ethyl oleate-cremophor EL-alcohol(35:32.5:32.5),以0.01 mol·L-1HCl稀释10倍后,平均粒径为30.79±1.57 nm,多分散系数PDI为0.132±0.025.结论 胰岛素磷脂复合物可以增加胰岛素在油酸乙酯中的溶解度,其自微乳制剂的制备方法简单,稀释后粒径均一.     

自微乳化释药系统研究进展

近年来,药剂学领域出现许多增加水难溶性药物溶解度和吸收的技术,其中自乳化释药系统(self-emulsifying drugdelivery systems,SEDDS)得到了广泛的发展。SEDDS 是由药物、油、乳化剂及助溶剂等组成的一种油状混合物,在体外轻微振荡或体内胃肠道的蠕动下自发的形成一种热力学稳定的乳状液,其粒径大约100～300 nm,粒径小于100 nm的乳剂称为自微乳化释药系统(self-microemulsifying drugdelivery systems,SMEDDS)。与 SEDDS 相比,SMEDDS 的最大优点是粒径小、溶液澄清透明、药物增溶量大、制剂更稳定。本文就 SMEDDS 的处方组成、结构与理化性质、质量评价以及应用等方面作一简要综述。1 处方组成SEDDS 的基本处方组成包括药物、油、乳化剂及助溶剂等。SMEDDS 的基本处方组成与 SEDDS 相同,其特殊性在     

三元相图法研究更昔洛韦自微乳化释药系统处方

目的采用自微乳化技术,研究更昔洛韦自微乳化释药系统,探究其最佳处方配比。方法通过溶解度实验对油相、表面活性剂、助表面活性剂进行选择,找到最佳组份;通过三元相图实验并结合乳液粒径的测定寻找出更昔洛韦最佳的处方配比。结果更昔洛韦自微乳化处方油相为IPM,乳化剂为cremophor RH40,助乳化剂为PEG 400(1∶1.5∶1.5)。结论初步成功地制备了更昔洛韦自微乳化释药系统。     

甘草酸磷脂复合物自乳化胶囊与肠溶胶囊的药动学比较

目的以市售甘草酸二铵肠溶胶囊为参比制剂,考察自制甘草酸磷脂复合物自乳化胶囊在Beagle犬体内的相对生物利用度。方法Beagle犬6只,自身交叉对照、单剂量灌胃甘草酸磷脂复合物自乳化胶囊或市售肠溶胶囊。采用HPLC测定血浆中的甘草酸浓度,DAS2．0程序拟合药代动力学数据。结果参比制剂和受试制剂主要的药动学参数：Tmax分别为（6．00±0．000）h,（2．917±0．585）h;Cmax分别为（12．756±1．075）mg·L^-1,（17．75±1．604）mg·L-1;AUC0-t分别为（150．89±22．850）mg·h·L-1,（211．196±40．880）mg·h·L^-1;AUC分别为（159．39±21．862）mg·h·L^-1,（221．287±2．164）mg·h·L^-1,甘草酸磷脂复合物自乳化制剂相对生物利用度（F％）为139．76％。结论Beagle犬体内甘草酸的药动学规律均符合一级吸收二室模型,与市售胶囊剂相比,自乳化制剂的Cmax、AUC0-t,AUC0-∞均高于肠溶胶囊,表明自乳化制剂能显著提高药物的生物利用度,初步达到了设计要求。     

银杏黄酮磷脂复合物自乳化释药系统处方研究

目的:优化银杏黄酮磷脂复合物自乳化释药系统处方。方法:以银杏黄酮磷脂复合物在不同种类及比例的油相、表面活性剂中的溶解度为考察指标,筛选自乳化释药系统处方。结果:该处方制备的银杏黄酮磷脂复合物自乳化软胶囊能够迅速溶解并乳化,在蒸馏水、pH6.8磷酸缓冲液和0.1mol/L的HCl中,该系统中的银杏黄酮在45分钟内的溶出度均在80%以上。结论:该自乳化释药系统大大提高了银杏黄酮在水中的溶出度。     

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.     

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.