大黄酚脂质体的制备工艺研究

目的:对大黄酚脂质体的处方和制备工艺进行研究,并评价其质量。方法:采用薄膜-超声分散法制备了大黄酚脂质体,并对制剂的包封率、形态学、粒径分布、稳定性等进行研究。结果:本研究制备的大黄酚脂质体处方为药脂比3∶30,脂材比1∶3,成膜温度为45℃,缓冲溶液pH为8.2,得到的脂质体粒径均匀,包封率达86.9%。结论:采用薄膜-超声分散法制备的大黄酚脂质体具有较高包封率和稳定性。     

Box-Behnken效应面法优化制备氯诺昔康柔性脂质体

目的采用Box-Behnken效应面法筛选最佳处方,制备氯诺昔康柔性脂质体。方法采用薄膜分散水化法制备脂质体,分别以磷脂浓度、磷脂与胆固醇质量比、脂药质量比、吐温80与总脂质质量比为考察对象,以包封率、粒径为评价指标,采用4因素3水平Box-Behnken效应面设计法筛选氯诺昔康柔性脂质体的最佳处方。采用葡聚糖G50微柱离心法测定包封率,动态激光散射法测定脂质体的粒径和ζ-电位,采用透射电镜观察制得的脂质体形态,并考察脂质体的体外释放。结果最优处方工艺条件为磷脂质量浓度为16.94 g·L~(-1),磷脂与胆固醇质量比为4.46∶1.00,总脂质与吐温80质量比8.12∶1.00,脂药质量比18.65∶1.00。以最优处方制备的氯诺昔康柔性脂质体平均粒径较小(93.86±7.58)nm、ζ-电位较好[-(20.21±2.31)mV]、包封率较高(90.23±1.46)%,实际值与预测值偏差较小。质量分数为82.06%的药物在24h内从脂质体中释放出来,具备明显的缓释特性。结论采用Box-Behnken效应面法优化氯诺昔康柔性脂质体工艺处方是可行的。     

苯丁酸氮芥脂质体的制备及处方因素考察

目的 制备苯丁酸氮芥脂质体并优化其处方。方法 薄膜超声分散法制备苯丁酸氮芥脂质体,采用微柱离心-HPLC法测定其包封率,以包封率为考察指标,研究膜材比、药脂比、水相介质pH值以及磷脂浓度等因素对脂质体包封率的影响;通过正交试验对处方进行优化,并进行质量评价。结果 苯丁酸氮芥脂质体优化后的制备处方为胆固醇与磷脂质量比1∶3、药脂比1∶10、水相介质pH值为7.4、磷脂浓度为0.3%。按该处方制得的苯丁酸氮芥脂质体包封率>87%,平均粒径为84.71 nm,PDI为0.167。结论 优选处方稳定可行,制备的苯丁酸氮芥脂质体包封率高、粒径小且均匀。     

高乌甲素脂质体凝胶制备工艺筛选实验研究

目的：研究乙醇注入法制备高乌甲素脂质体凝胶的工艺。方法：采用单因素实验分析药脂比、磷脂胆固醇比、水化液pH、水化温度筛选影响包封率及载药量的因素,再采用正交试验优选最佳处方;制备得到高乌甲素脂质体后,单因素实验筛选最佳卡波姆用量及pH,得到最适宜脂质体凝胶配方。结果：采用正交试验法确定高乌甲素脂质体最佳处方工艺组合为卵磷脂：胆固醇为6∶1、药脂比为1∶10、水化温度为55 ℃,水化液pH值为7.0,该处方制备的脂质体包封率高,粒径分布均匀;当卡波姆-940用量为1%、在pH 6~7时,所制备的高乌甲素脂质体凝胶易涂布、黏度适宜。结论：制备的高乌甲素脂质体凝胶工艺简单可行,包封率较高,可以进一步研究。     

CA4P脂质体的制备工艺研究

目的 研究CA4P脂质体的处方及制备工艺.方法 以包封率为主要评价指标考察制备方法;用透射电镜和粒径测定仪表征脂质体的形态和粒径;用HPLC法测定脂质体中CA4P的包封率和载药量;以正交设计筛选优化最佳处方工艺.结果 脂质体的平均粒径为167 nm,Zeta电位为-24.3 mV,最佳工艺处方的药-脂比为1:12,磷脂-胆固醇为8:1,有机相-水相体积为4:1,水合介质为0.9%NaCl;制备3批脂质体的平均包封率为58%、载药量为4.8%.结论 逆相蒸发-探头超声法可制备具有较高包封率的CA4P脂质体.     

灯盏花素脂质体的制备工艺

目的研究灯盏花素脂质体的制备工艺。方法采用薄膜蒸发-探头超声法和冷冻干燥法制备灯盏花素脂质体,在单因素考察基础上采用正交试验设计。以包封率为评价指标,筛选脂质体制备的最佳工艺条件。冻干品水合后,在电镜下观察灯盏花素脂质体的形态,利用马尔文测定仪测定脂质体的粒径,用RP-HPLC法测定其包封率。结果灯盏花素脂质体的最佳工艺处方为药脂比1∶5,SPC∶CH为2∶1,二氯甲烷用量为10 ml。冻干保护剂蔗糖用量为10%。制备3批脂质体,包封率平均为87.5%,平均粒径为378.3 nm。结论所制脂质体包封率较高,粒径分布较均匀。     

伊曲康唑柔性脂质体的制备及体外性能研究

摘要：目的:制备伊曲康唑柔性脂质体,并考察其体外透皮性能。方法:以大豆卵磷脂为成膜材料和聚山梨酯80为边缘活化剂,薄膜分散法制备伊曲康唑柔性脂质体,考察粒径、Zeta电位、包封率、载药量及稳定性。采用Franz扩散池,以大鼠皮肤为透皮屏障,考察伊曲康唑柔性脂质体及其溶液的体外透皮性能差异。结果:伊曲康唑柔性脂质体平均粒径为（222.5±15.34） nm,多分散系数（PDI）为（0.226±0.09）,Zeta电位为（-5.09±1.52） m V,平均包封率为（83.80±2.18）%。体外透皮实验表明,伊曲康唑脂质体中伊曲康唑12 h的累积渗透量(Q12)是伊曲康唑溶液的2.21倍;渗透速率(Jss)是伊曲康唑溶液的2.20倍;皮肤滞留量（Qs）是伊曲康唑溶液的6.2倍。结论:伊曲康唑柔性脂质体可显著提高伊曲康唑的体外累积透皮量和皮肤滞留量,有望成为新型局部给药制剂。     

Box-Behnken效应面法优化制备主动载药盐酸小檗碱脂质体

目的采用Box-Behnken效应面法筛选最佳处方,制备盐酸小檗碱脂质体。方法采用薄膜分散-p H梯度法制备脂质体,分别以磷脂与胆固醇质量比、脂药质量比、外水相p H值、孵化温度为考察对象,以包封率、粒径和载药量为评价指标,采用4因素3水平Box-Behnken效应面设计法筛选盐酸小檗碱脂质体的最佳处方。采用阳离子交换树脂微柱离心法测定包封率,动态激光散射法测定脂质体的粒径,并采用透射电镜观察制得的脂质体形态。结果最优处方工艺条件为磷脂与胆固醇质量比为3.38∶1,脂药质量比为22∶1,外水相p H为6.88,孵化温度为59℃。以最优处方制备的盐酸小檗碱脂质体平均粒径、包封率、载药量与预测值偏差较小。结论采用Box-Behnken效应面法优化盐酸小檗碱脂质体工艺处方是可行的。     

正交试验优选硫酸铵梯度法制备苦参碱脂质体的工艺研究

目的 以包封率为指标优选苦参碱脂质体的制备工艺.方法 以氢化大豆卵磷脂(HSPC)和胆固醇(Ch)为膜材,采用薄膜超声-硫酸铵梯度法制备脂质体.通过正交设计优化处方工艺,葡聚糖凝胶法分离游离药物,HPLC法测定月旨质体中苦参碱的包封率.结果 最佳工艺为:HSPC:Ch=3∶1,探头超声10 min,药脂比为1:15,包封率均值为50.68％.结论 优化后的工艺可提高苦参碱脂质体的包封率,此工艺条件简单,可操作性强,适于实验室条件下制备苦参碱脂质体.     

吉非替尼脂质体的处方工艺优化

目的优化吉非替尼脂质体(gefitinib liposome,GFB-L)的处方组成及工艺条件。方法采用逆相蒸发、改良乙醇注入、薄膜分散3种被动载药法和6种不同梯度的主动载药法制备GFB-L,分别以阳离子交换树脂分离-紫外分光光度法和激光粒度仪测定GFB-L的包封率和粒径,采用单因素考察脂质体膜材组成对包封率及粒径的影响,并进一步通过正交设计法优化GFB-L的处方工艺。结果确定最优处方工艺为∶m(氢化大豆卵磷脂):m(胆固醇)∶m[聚乙二醇单甲醚(2000)-胆固醇琥珀酸酯]=3∶1∶1,m(药)∶m(脂)=1∶8,水化介质:150 mmol.L-1硫酸铵溶液,除盐时间:10 min,载药温度:50℃,载药时间:10 min。结论通过处方工艺优化,GFB-L的平均包封率达97.38%,平均粒径为132.2 nm。     

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.