伏立康唑N-三甲基壳聚糖包衣脂质体的制备及体外性质考察

摘 要 目的：制备N 三甲基壳聚糖（TMC）包衣伏立康唑（VCZ）脂质体冻干品,对其体外性质进行考察。方法: 采用薄膜分散法制备VCZ脂质体（VCZL）,以季铵化程度60%的TMC（TMC60）对其进行包衣。处方采用正交试验进行优化,并筛选出最优的冻干保护剂制备冻干品。考察其形态、粒径及Zeta电位,并用透析袋法研究体外释药特性。结果: TMC60包衣VCZL最优处方组成为质量比卵磷脂 ∶〖KG-*4〗胆固醇4 ∶〖KG-*4〗1,药物 ∶〖KG-*4〗类脂1 ∶〖KG-*4〗20,TMC60溶液浓度为0.15 mg·ml-1,PBS的pH为7.4。TMC60包衣VCZL形态圆整,平均粒径为（590.4±16.0）nm,冻干复水化后平均粒径为（503.2±20.5）nm;VCZL的Zeta电位为-46.4 mV,TMC60包衣后为+54.9 mV,冻干复水化后为+52.6 mV;冻干前后平均包封率无明显变化;体外释药符合Higuchi方程。结论: TMC60包衣VCZL粒径均匀,带正电荷,包封率较高,具有缓释性,冻干对其主要性质无显著影响。     

N-三甲基壳聚糖包衣羟喜树碱脂质体冻干剂的研制

摘 要 目的:对N-三甲基壳聚糖（TMC60）包衣羟喜树碱脂质体（HCPTL）冻干剂的处方及制备工艺进行优化。方法: 采用逆向蒸发法制备HCPTL,并用TMC60包衣,经高压乳匀得到纳米级脂质体。以包封率为考察指标,正交试验优选处方及工艺,并筛选最佳的冻干保护剂进行冷冻干燥。对复水化后脂质体的形态、Zeta电位、粒径等进行考察。结果:TMC60包衣HCPTL的最佳处方及工艺为：药脂比为1∶30,胆固醇:卵磷脂为1∶3,旋蒸温度为35℃,TMC60浓度为0.35%,最佳冻干保护剂为15%（w/v）的海藻糖。复水化后形态圆整,平均包封率为(82.2±2.3)%（n=3）,Zeta电位为（53.2±2.0 ）mV,平均粒径为（92.4±18.5）nm。结论:TMC60包衣HCPTL冻干剂具有包封率高,表面带正电荷等特点,为其进一步研究奠定了基础。     

N-三甲基壳聚糖包衣的盐酸阿霉素脂质体的制备

研制N-三甲基壳聚糖（TMC）包衣的盐酸阿霉素（ADM）脂质体。方法：采用硫酸铵梯度法制备ADM脂质体,以包封率为指标,筛选盐酸阿霉素脂质体最佳处方;合成不同季铵化程度的TMC,并对最佳ADM脂质体进行包衣。结果：未包衣ADM脂质体平均粒径为（378．6±5．2）nm,Zeta电位为（-62．08±2．5）mv,平均包封率为（62．27±1．75）％（n=3）。TMC包衣后,脂质体粒径增大,并随着TMC季铵化程度的增大,Zeta电位显著增大（p＜0．05）;TMC20、TMC40、TMC60包衣脂质体体外释药曲线符合Higuchi方程,分别为：Q=7．6315＋3．7863t1／2（r=0．9292）,Q=6．9647＋3．5709t1／2（r=0．9318）,Q=7．3451＋2．7665t1/2（r=0．9357）。结论：TMC包衣ADM脂质体的制备工艺可行,其表面带有较高正电性,为下一步研究其血管靶向性打下基础。     

乳香挥发油脂质体的制备及质量评价

目的研制乳香挥发油脂质体并进行质量评价。方法采用正交设计法进行试验,以包封率为指标筛选处方,并对脂质体形态、粒径大小与分布、Zeta电位及包封率等质量指标进行评价。结果最佳处方为A3B3C2,即：胆固醇与磷脂的重量比为1：6、药脂重量比为1：6、制备温度为60℃。质量评价结果表明脂质体圆整均匀,平均粒径、Zeta电位和包封率分别为150nm、-39．5mV和（87．7％±1．23％）。结论乳香挥发油脂质体的制备工艺方便、科学,各项质量指标良好。     

N-三甲基壳聚糖包覆的水飞蓟宾脂质体的制备及处方工艺优化

目的:制备N-三甲基壳聚糖(TMC)包覆的水飞蓟宾脂质体(SLBL)(TMC60-SLBL),并优化处方工艺。方法:比较薄膜分散法、复乳法、逆向蒸发法对SLBL包封率的影响;以磷脂质量浓度、磷脂-胆固醇质量比、药脂质量比、水合温度为因素,以包封率为指标,采用正交试验优选TMC60-SLBL的处方工艺,并进行验证;比较优化处方所制TMC60-SLBL在4、25℃下30 d内的稳定性,及其与未包覆SLBL的粒径、Zeta电位。结果:3种方法中,薄膜分散法所制SLBL包封率较高,且包封率在剪切前后差异无统计学意义(P>0.05)。TMC60-SLBL最优处方工艺为磷脂质量浓度6 mg/ml、磷脂-胆固醇质量比40∶1、药脂质量比1∶30、水合温度45℃,其包封率为(82.08±2.6)%,RSD=3.17%(n=3);在4℃下稳定性更好。SLBL和TMC60-SLBL的粒径分别为(131.9±1.9)、(161.2±2.0)nm,Zeta电位分别为(-23.18±1.14)、(36.73±2.84)m V。结论:成功制得TMC60-SLBL,且处方简单、方法可行,产品包封率较高。     

眼用司帕沙星阳离子脂质体原位凝胶的研制

目的:研制司帕沙星(SF)眼用阳离子脂质体-原位凝胶(ISG)。方法:采用pH梯度法制备SF脂质体(SFL),用季胺化程度为60%的N-三甲基壳聚糖(TMC60)包衣,用正交试验筛选其最佳处方及工艺,再与泊洛沙姆P407为基质的温度敏感材料混合,制备TMC60包衣的SFL-ISG,并对其形态、粒径、Zeta电位、凝胶溶蚀及释药等体外性质进行考察。结果:本品形态圆整,粒径分布均匀,TMC60包衣后Zeta电位由负转正,药物释放和凝胶溶蚀均呈现良好的零级释放特征。结论:本品结合阳离子脂质体与原位凝胶技术成功制备了TMC60包衣的SFL-ISG,为其体内研究奠定了实验基础。     

维生素A棕榈酸酯阳离子脂质体原位凝胶的制备及其兔角膜滞留性考察

目的:以维生素A棕榈酸酯(VAP)为主药,制备阳离子脂质体原位凝胶,并对其兔角膜滞留性进行考察。方法:采用薄膜分散法制备VAP脂质体(VAPL),并用不同季铵化程度的NC-三甲基壳聚糖(TMC)包衣制备CAP阳离子脂质体(TMCVAPL),再以泊洛沙姆407为基质,制备VAP阳离子脂质体原位凝胶(TMC-VAPL-ISG)。采用荧光示踪法对其兔角膜的滞留时间进行考察。结果:透射电镜显示VAP脂质体粒径分布均匀,未包衣时平均粒径为(62.98±0.078)nm,Zeta电位为(-11.2±0.57)mV,平均包封率为(70.62±0.66)%(n=3);TMC包衣后,脂质体粒径明显增大(P<0.05),平均包封率为(69.49±0.79)%,随着TMC季铵化程度的增大,Zeta电位显著增大(P<0.05)。与未包衣和包衣的CAPL相比,TMC-CAPLISG兔角膜的滞留时间延长2倍,且随着TMC季铵化程度的提高,滞留效果逐渐增强(P<0.05)。结论:TMC-VAPL-ISG具有阳离子脂质体和原位凝胶的优势,能明显延长兔角膜滞留时间。     

N-三甲基壳聚糖的季铵化程度对溴吡斯的明包衣脂质体体外性质的影响

目的考察N-三甲基壳聚糖(TMC)的季铵化程度(DQ)对TMC包衣溴吡斯的明脂质体(PB-L)体外性质的影响。方法逆向蒸发法制备PB-L,以DQ分别为20%、40%及60%的TMC(即TMC20、TMC40、TMC60)对其进行包覆。对其形态进行观察,测定其粒径、Zeta电位及包封率,并对其体外释药特性进行考察。结果 TMC包衣PB-L外观呈圆整球形,具有明显的包衣层;TMC包衣后,PB-L粒径增加,且随DQ的增大而增大;包衣后PB-L的Zeta电位由负转正,且随DQ的增大而增大;DQ对包封率无显著性影响,平均包封率为(61.73±1.27)%(n=3);与未包衣PB-L相比,TMC包衣PB-L缓释性更显著,且释药速度随DQ的增大而降低。结论 DQ对TMC包衣PB-L的体外性质具有显著的影响。     

水溶性壳聚糖包覆多西他赛纳米脂质体的制备及性能研究

目的:制备羧甲基壳聚糖包衣多西他赛纳米脂质体,并考察其体外释放度。方法:采用薄膜分散法制备多西他赛阳离子脂质体,并用不同浓度的羧甲基壳聚糖包覆阳离子脂质体;用超滤法测定其包封率;用激光电位粒径测定仪分别测定其Zeta电位和粒径大小,并用透射电镜观察其形态;用透析法考察其体外释药性质。结果:所制的羧甲基壳聚糖包覆的脂质体包封率达99.98%;Zeta电位为-12.8 mV,平均粒径为(150±17)nm。结论:本实验制备的羧甲基壳聚糖包衣多西他赛纳米脂质体具有高包封率,粒径大小均匀,体外能显著延缓药物释放的性质。     

雷公藤红素纳米结构脂质载体的制备工艺优化及其表征

目的:优化雷公藤红素(Cel)纳米结构脂质载体(Cel-NLC)的制备工艺,并对其进行表征。方法:采用熔融乳化超声法制备Cel-NLC。在单因素试验基础上,以Cel包封率为指标,采用星点设计-响应面法优化液态脂质比例(占总质量的比例)、复合乳化剂用量及主药用量,并进行验证试验。利用纳米粒度及Zeta电位分析仪测定最优处方下制备的Cel-NLC的粒径及Zeta电位,在透射电镜下观察其形态。结果:最优处方的液态脂质比例为39%,复合乳化剂用量为196 mg,主药用量为8 mg。所制3批Cel-NLC的平均包封率为87.22%、平均粒径为(41.2±1.1)nm、平均Zeta电位为(-18.4±0.2)mV(n=3),电镜下观察其外观呈类球形。结论:优化的处方工艺方法简便、稳定可行,适用于Cel-NLC的制备。     

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.

---

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.