紫杉醇纳米脂质体凝胶剂的制备及体外透皮研究

目的制备紫杉醇纳米脂质体凝胶剂,考察其粒径、粒径分布、包封率、体外释放度及透皮特性。方法采用薄膜蒸发高压微射流法制备紫杉醇纳米脂质体,以卡波姆为凝胶基质,研制紫杉醇纳米脂质体凝胶剂,采用正交试验探索最佳工艺。用粒径测定仪测定脂质体的粒径及其粒径分布,低速-超速相结合法测定包封率,透析膜扩散法进行体外释放试验,以离体小鼠皮结合改良Franz扩散装置考察其体外透皮特性。结果紫杉醇纳米脂质体的最佳工艺:卵磷脂的含量为2%,药物与磷脂质量比为1∶30,磷脂与胆固醇的质量比为10∶1。测得的粒径为81.8 nm;粒径分布系数为0.180;平均包封率73.2%。纳米脂质体凝胶剂72 h累积释放百分率为79.04%;48 h的单位面积累积渗透量为429.68μg·cm?2。结论该制剂制备工艺简单,易于涂布,具有较高的包封率,粒径较小且分布均匀,体外释放缓慢。纳米脂质体能促进脂溶性药物紫杉醇透过皮肤。     

光甘草定醇质体与立方液晶纳米粒皮肤滞留量比较及抗豚鼠皮肤光老化作用观察

目的 制备光甘草定醇质体与立方液晶纳米粒,通过测定2种纳米制剂在离体豚鼠皮肤中的滞留量优选出适合光老化经皮给药的制剂。建立光老化模型,通过观察优选制剂对豚鼠光老化模型的治疗效果来评价药物的疗效。方法 采用注入法制备光甘草定醇质体,高压均质法制备光甘草定立方液晶纳米粒,利用Franz扩散装置考察光甘草定醇质体、立方液晶纳米粒凝胶离体鼠皮中的滞留量,优选出光甘草定经皮给药治疗光老化的纳米制剂。紫外线照射背部剃毛豚鼠建立皮肤光老化模型。雌性豚鼠随机分为模型组、基质（给予空白凝胶0.5 g/只）组、维甲酸（阳性对照,0.5 g/只）组和甘草定立方液晶纳米粒凝胶高、低剂量（0.50、0.25 g/只）组,治疗2周后,通过肉眼观察、HE染色、Masson染色等评价其治疗效果,用水份测定仪观察其对豚鼠皮肤含水量的影响。结果 2种纳米制剂凝胶的鼠皮滞留量最高者为光甘草定立方液晶纳米粒凝胶。豚鼠皮肤光老化模型建立成功,HE染色、Masson染色等结果表明光甘草定立方液晶纳米粒对光老化有明显的治疗效果,使光老化皮肤的含水量显著升高（P<0.05）。结论 光甘草定立方液晶纳米粒在离体鼠皮中的滞留较高,对豚鼠皮肤光老化模型治疗效果显著,为光甘草定的临床应用提供了新的方法与思路。     

N-三甲基壳聚糖包覆司帕沙星纳米脂质体离体角膜滞留性及刺激性研究

摘 要 目的：对N-三甲基壳聚糖（TMC）包覆司帕沙星（SL）纳米脂质体的角膜滞留性及兔眼刺激性进行考察。方法: 采用悬挂泡技术和束缚泡技术,对TMC包覆SL纳米脂质体、SL纳米脂质体及SL滴眼液在兔离体眼球表面的接触角及解吸附动力学进行研究;以Draize评分法评价3种SL制剂多次给药后对兔眼的刺激性。结果: 离体角膜表面接触角的大小顺序为：SL滴眼液＞SL纳米脂质体＞TMC包覆SL纳米脂质体,与SL滴眼液相比,两种SL纳米脂质体的解吸时间明显延长,且以TMC包覆的SL纳米脂质体解析时间最长。3种SL制剂在多次给药后,对兔眼无明显的刺激性。结论:与普通滴眼液相比,SL纳米脂质体具有较好的角膜滞留性,TMC包覆后,滞留性进一步增强,并具有较好的安全性,值得进一步开发研究。     

难溶性药物logP值对纳米脂肪乳载药特性的影响

目的 考察难溶性药物油/水分配系数(log P值)对纳米脂肪乳载药量、体外释药特性、相分布等载药特性的影响。 方法 选取6种难溶性药物:尼莫地平(NIM)、多西紫杉醇(DTX)、姜黄素(CUR)、紫杉醇(PTX)、替尼泊苷(TEN)、水飞蓟宾(SLB),分别考察其log P值与PEG400中溶解度、载药纳米脂肪乳的载药量、粒径、Zeta电位、体外释药特性以及相分布等的关系。 结果 随着log P值的增加,药物在PEG400中的溶解度呈先上升后下降的趋势,在纳米脂肪乳中的载药量增高,体外释放速率减慢,在油相中的分布增加,在乳化剂层的分布减小;药物log P值与载药纳米脂肪乳的粒径及Zeta电位无关。 结论 可综合考虑药物的log P值及PEG400中的溶解度,用以初步判断纳米脂肪乳的载药特性。     

甲氨蝶呤柔性纳米脂质体凝胶的构建及体外经皮渗透性研究

目的 制备甲氨蝶呤(methotrexate,MTX)柔性纳米脂质体凝胶,并研究其体外经皮渗透行为.方法 采用逆向蒸发法制备MTX柔性纳米脂质体,以卡波姆940为基质制成脂质体凝胶,并考察其初步稳定性;Franz扩散池研究MTX柔性纳米脂质体凝胶与普通凝胶的经皮渗透规律.结果 脂质体凝胶4℃下稳定性良好;体外透皮试验表明,MTX柔性纳米脂质体凝胶的累积透过量明显＜MTX普通凝胶(P＜0.05),皮肤滞留量＞MTX普通凝胶(P＜0.05).结论 MTX柔性纳米脂质体凝胶可显著提高药物的皮肤滞留量,而不增加药物进入血液循环的量,能有效降低药物潜在的全身毒性,有望成为MTX局部治疗的新剂型.     

N-三甲基壳聚糖包覆司帕沙星纳米脂质体原位凝胶的研制及体外释药研究

摘 要 目的：制备眼用N-三甲基壳聚糖（TMC）包覆的司帕沙星（SL）纳米脂质体原位凝胶（ISG）,并考察其体外释放度。方法: 采用pH梯度法制备SL脂质体,经高压均质至纳米级,用TMC包衣。以胶凝温度为指标,优选ISG基质泊洛沙姆407的最佳浓度,采用冷法制备TMC包覆SL纳米脂质体ISG。对TMC包覆SL纳米脂质体ISG中脂质体的形态、粒径、Zeta电位及包封率进行考察;以TMC包覆SL纳米脂质体为对照,采用无膜溶出模型考察其体外释药特性。结果: 泊洛沙姆407的最佳浓度为25%,在人工泪液中的胶凝温度为23.6 ℃,稀释后的胶凝温度为33.5 ℃。TMC包覆SL纳米脂质体ISG中脂质体形态圆整,平均粒径为（96.8±1.5）nm,Zeta电位为（46.2±1.4）mV,包封率为（76.6±2.4）%,与TMC包覆SL纳米脂质体相比无明显变化。TMC包覆SL纳米脂质体ISG药物释放和凝胶溶蚀均为符合零级动力学特征,且与TMC包覆SL纳米脂质体相比,缓释性更为显著。结论:TMC包覆SL纳米脂质体ISG胶凝温度理想,并可延缓药物释放。     

十一酸睾酮二元醇质体凝胶剂体内外透皮特性研究

摘 要 目的：对十一酸睾酮（TU）二元醇质体凝胶进行体内外透皮考察。方法: 采用注入法制备TU二元醇质体,以卡波姆941为凝胶基质,制备TU二元醇质体凝胶剂;以小鼠皮肤为屏障,采用Franz扩散池法对其体外透皮特性进行考察;以大鼠为实验动物,背部给予TU二元醇质体凝胶剂后,于设定的时间点测定血浆中TU浓度,计算药动学参数,并与TU二元醇质体进行比较。结果: TU二元醇质体及其凝胶的体外累积透皮百分率Q与时间t均符合一级动力学模型,线性方程分别为：Q=8.68t+6.78（r=0.998 2）和Q=6.09t+3.09（r=0.999 3）,稳态透皮速率分别为8.68 μg·cm^-2·h^-1和6.09 μg·cm^-2·h^-1,24 h后TU在皮肤中的滞留量分别为（208.80±55.26）μg·g^-1和（225.60±38.90）μg·g^-1;大鼠体内TU二元醇质体及其凝胶的主要药动学参数分别为：Cmax（18.50±2.75）mg·L^-1和（20.80±2.42）mg·L^-1;tmax（6.20±0.14）h和（9.54±0.52）h;AUC0-48h（336.74±2.05）h和（486.30±1.68）h。结论:TU二元醇质体及其凝胶均呈现较好的体内外透皮特性,且在缓释性上凝胶剂表现更优。     

胰岛素柔性纳米脂质体的口腔给药研究

目的探讨柔性纳米脂质体经口腔粘膜转运蛋白多肽类药物的可能性。方法用反相蒸发法制备胰岛素柔性纳米脂质体和普通脂质体,对其包封率、形态和粒径大小进行测定。以家兔为动物模型,口腔给药(bu)后,进行体内降糖实验,同时测定胰岛素水平变化。结果胰岛素柔性纳米脂质体与普通脂质体的包封率分别为(18.9±1.8)%和(22.1±2.2)%;粒径分别为(42±20) nm和(60±34) nm。透射电镜下,胰岛素柔性纳米脂质体的指纹状结构比普通脂质体更多,其他无明显区别。以sc胰岛素溶液(1 U·kg^-1)为对照,bu胰岛素柔性纳米脂质体组(10 U·kg^-1)的药理相对生物利用度为15.59%,相对生物利用度为19.78%,高于bu胰岛素溶液对照组(P<0.05)、胰岛素普通脂质体组(P<0.05)及空白柔性纳米脂质体与胰岛素混合物组(P<0.05)。结论胰岛素柔性纳米脂质体可能成为经口腔粘膜转运蛋白多肽类药物的有效载体。     

新型喜树碱纳米凝胶给药系统的构建及体外透皮特性研究

目的 制备新型喜树碱纳米凝胶给药系统(CPT-PPO gel),并对其含量、理化性质和体外透皮特性进行考察。方法 以乙交酯-丙交酯共聚物(PLGA)包裹抗银屑病药物喜树碱(CPT)作为纳米系统的核,将聚酰胺-胺(PAMAM,G3.0)包裹在PLGA表面作为纳米系统的壳,采用乳化溶剂挥发法制备载喜树碱纳米系统(CPT-PLGA-PAMAM, CPT-PP),并用油酸(OA)进行修饰,得到经表面改性的核壳纳米给药系统(CPT-PLGA-PAMAM-OA, CPT-PPO)。采用HPLC法测定纳米乳中喜树碱的含量,采用透射电镜和激光粒径测定仪分别考察纳米粒的形态和粒径。以羟丙甲基纤维素(HPMC)为基质,制备CPT-PPO gel,并采用Franz扩散池对其体外透皮特性进行考察。结果 制得的CPT-PPO gel平均粒径为(246.7±5.4) nm,包封率为(78.7±6.9)%,含量稳定,在4℃时具有良好的稳定性。体外透皮实验表明,纳米凝胶CPT-PPO gel、CPT-PP gel比普通凝胶CPT gel有更高的皮肤渗透量和滞留量(P<0.01),且CPT-PPO gel在皮肤渗透量和滞留量上均显著高于CPT-PP gel(P<0.05)。结论 经过OA修饰的CPT-PPO gel可以显著提高药物的皮肤吸收量和滞留量,有望成为应用CPT局部治疗银屑病的新剂型。     

基于药物-皮肤的相互作用探究盐酸特比萘芬体外透皮特性

目的 考察盐酸特比萘芬的体外透皮特性，探究盐酸特比萘芬与皮肤的相互作用，基于药物-皮肤相互作用阐明盐酸特比萘芬透皮特性的机制。方法 比较盐酸特比萘芬经皮渗透及其皮内滞留以及在皮肤各层的分布；利用衰减全反射红外光谱、差示扫描量热、拉曼光谱研究药物与皮肤的相互作用，并对药物与角质层角蛋白及脂质的相互作用进行计算机模拟和计算。结果 盐酸特比萘芬经皮渗透后高滞留低渗透，滞留的药物多分布于角质层。盐酸特比萘芬与角质层中脂质和角蛋白均有相互作用，该作用使药物自身难于透过皮肤，并导致较大的透过变异性。结论 盐酸特比萘芬与皮肤脂质和角蛋白的相互作用是其表现出典型的皮肤低渗透、高滞留特性的机制之一。本研究为盐酸特比萘芬体外透皮高滞留、低渗透特性提供理论依据。     

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.     

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.     

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.