大蒜素聚氰基丙烯酸正丁酯纳米粒的制备工艺研究

目的：研制大蒜素聚氰基丙烯酸正丁酯纳米粒并对处方与制备工艺进行优化筛选。方法：以生物降解型聚氰基丙烯酸正丁酯为载体材料，采用乳化聚合法制备大蒜素聚氰基丙烯酸正丁酯纳米粒；以载药量、包封率、形态和粒径分布为评价指标，通过单因素试验考查、均匀设计法优化制备工艺。结果：按优化处方与制各工艺条件，制得纳米粒球形圆整、分散良好，算术平均粒径为113．4nm，粒径分布范围为11．7—146．8nm，载药量为18．57％，包封率为92．87％。结论：经优化筛选出的工艺是大蒜素聚氰基丙烯酸正丁酯纳米粒的最佳制备工艺。     

苦参碱聚氰基丙烯酸正丁酯纳米粒冻干粉针剂的制备及体外释放

采用乳化聚合法制备苦参碱聚氰基丙烯酸正丁酯纳米粒,以包封率为考察指标,均匀设计优化处方与工艺.所得纳米粒平均粒径为(157.4±22.4)nm,包封率为83.8%,载药量为9.4%,体外释药具有双相动力学特征.     

正交设计优选阿糖胞苷聚氰基丙烯酸正丁酯纳米粒制备工艺

目的:制备阿糖胞苷聚氰基丙烯酸正丁酯(Ara-C-PBCA-NP)纳米粒.方法:在单因素考察的基础上,通过正交设计优选处方和制备工艺,并对优化条件下制备的Afa-C-PBCA-NP胶体溶液进行质量评价.结果:制备的Ara-C-PBCA-NP平均粒径为56 nm,平均粒径跨度为1.226,载药量为11.77%,包封率为53.38%.结论:所制备的稳定的纳米粒给药系统,为阿糖胞苷的临床应用提供了更广阔的前景.     

葛根素磷脂复合物纳米粒的制备及体外评价

目的制备葛根素磷脂复合物,以聚氰基丙烯酸正丁酯(PBCA)为载体材料,制备葛根素磷脂复合物纳米粒,并对其进行体外评价。方法采用界面缩合聚法制备纳米粒。以复合率、包封率和载药量为评价指标,通过单因素和正交试验法优选处方和工艺。结果葛根素磷脂复合物的最佳处方及工艺:反应溶剂为无水乙醇,葛根素与磷脂的投料比为1∶2;葛根素磷脂复合物纳米粒的最佳处方及工艺:pH=3.0、α-氰基丙烯酸正丁酯(α-BCA)的浓度为0.8%、V油相∶V水相=1∶60、葛根素磷脂复合物的投药量为1.0 mg。制备的纳米粒平均粒径为(115.1±3.45)nm、包封率为(90.03±1.80)%、载药量为(11.80±0.12)%。体外释药在24 h累积释放量约为80%。结论本研究所制备的葛根素磷脂复合物纳米粒包封率和载药量高、性质稳定、体外释药具有缓释行为。     

云芝糖肽聚氰基丙烯酸正丁酯纳米囊的制备工艺优选

目的 优选界面聚合法制备云芝糖肽聚氰基丙烯酸正丁酯纳米囊的工艺.方法 以包封率为指标,通过正交试验设计优化处方.结果 制得的纳米囊外观圆整,粒径分布均匀,平均粒径为268.5 nm,包封率达83.7%.结论 云芝糖肽聚氰基丙烯酸正丁酯纳米囊制备工艺简单,优选的处方较好,所制得的微囊粒径小、分布窄,该工艺可行.     

注射用丝裂霉素C聚氰基丙烯酸正丁酯纳米粒的制备

采用乳化聚合法新鲜制备的注射用丝裂霉素C聚氰基丙烯酸正丁酯纳米粒平均粒径为(106.8±7.2)nm,平均包封率(92.1±2.3)%,载药量(7.3±0.2)%.半数致死剂量(LD50)本品为54.3mg/kg,注射用丝裂霉素为13.6mg/kg.     

葛根素聚氰基丙烯酸丁基酯纳米粒的制备及质量评价

目的：制备葛根素聚氰基丙烯酸正丁酯纳米粒（P-PBCA）,并对其进行质量评价.方法：以包封率和载药量为指标,采用正交设计综合评分法优化P-PBCA处方.结果：最佳工艺为葛根素质量20 mg、氰基丙烯酸正丁酯体积分数0.6％,pH为2.0,优化所得P-PBCA为球状,包封率为（78.13±7.42）％,载药量为（15.05±2.38）％;粒径（145.2±22.4） nm,Zeta电位（-28.7±1.1）mV.结论：正交设计综合评分法可用于P-PBCA的制备.     

布洛芬聚氰基丙烯酸烷酯纳米粒的制备

目的制备布洛芬聚氰基丙烯酸烷酯纳米粒(IBU-PACA-NP)。方法采用乙醚界面缩聚法制备布洛芬聚氰基丙烯酸烷酯纳米粒;以包封率、载药量为指标,在单因素考察处方及工艺条件基础上,采用正交设计法L9(34)对处方进行优化。结果按优化处方制备的纳米粒平均粒径为166 nm,包封率为96.60%,载药量为17.83%,Zeta电位为-20.2 mV。结论乙醚界面缩聚法制备的布洛芬聚氰基丙烯酸烷酯纳米粒粒径小,包封率和载药量符合要求,可用于口服或注射给药。     

盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶的制备

目的:制备盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶,并对其处方因素进行考察。方法:以氰基丙烯酸正丁酯为载体材料,采用乳化聚合法制备盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶,以粒径、外观为主要指标,用单因素方法优化处方,得到二步法制备纳米溶胶的条件和工艺。结果:制备的纳米溶胶的平均粒径为(82.6±15)nm,包封率为61.9%,载药量为34.2%(g/g),平均Zeta电位为(-25.1±9.92)mV。结论:本实验制备的盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶的粒径小,分布窄,稳定性好。     

替莫唑胺聚氰基丙烯酸正丁酯纳米粒的制备

目的:优化工艺制备替莫唑胺聚氰基丙烯酸正丁酯纳米粒(TMZ-PBCA-NP)。方法:以α-氰基丙烯酸正丁酯(BCA)为载体,采用乳化聚合法制备TMZ-PBCA-NP,并以PluronicF-68作为表面活性剂,通过考察粒径大小和包封率2个指标,在单因素实验初选的基础上,正交设计法优化处方和制备工艺。结果:制备TMZ-PBCA-NP的优化条件为反应体系pH2.5,用1%PluronicF-68作为表面活性剂,TMZ用量5 mg,BCA单体用量0.1 mL,按优化条件所制备的TMZ-PBCA-NP平均粒径(135.8±11.3)nm,多分散系数为0.19,表面电位(-24.8±2.2)mV,包封率(44.23±2.04)%,载药量(2.80±0.05)%。结论:通过优化处方和制备工艺,采用乳化聚合法可制备出TMZ-PBCA-NP,对拓展TMZ临床给药新剂型提供一定的参考。     

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.     

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.