卡维地洛固体分散体的制备与溶出度测定

目的：制备卡维地洛固体分散体,增加其溶解度和溶出速度。方法：以聚乙烯吡咯烷酮（PVP）、聚乙二醇－6000（PEG－6000）为载体,溶剂法和溶剂熔融法制备固体分散体,并进行体外溶出度研究。结果：载体比例越大,药物溶出愈快;且载体比例愈小,差异愈显著。载体为PVP所制固体分散体的体外溶出为总体优于载体为PEG－6000的固体分散体。结论：本试验所制卡维地洛固体分散体能加速体外溶出,为难溶于水药物提高生物利用度开辟一条途径。     

固体分散技术提高黄芩提取物溶出度的研究

目的：通过制备固体分散体，提高黄芩提取物的溶出度。方法：采用熔融法和溶剂法，制备聚乙二醇4000（PEG4000），聚乙二醇6000（PEG6000），聚乙烯吡咯烷酮K30（PVPK30）3种载体材料及不同比例条件下的固体分散体。通过比较原药材、固体分散体、机械混合物的溶出性能，从而确定制备的最佳方法和最佳比例。结果：不同载体不同比例的固体分散体均能提高药物的溶出度，且载体比例越大，药物的溶出越快，3种载体的增溶效果依次为PVPK30〉PEG4000〉PEG6000。结论：以PVP为载体，采用溶剂法所制备的药物/载体比例为1：6的固体分散体能显著提高黄芩提取物的溶出速率。     

水飞蓟素增溶方法的比较研究

目的：优选增加水飞蓟素溶解度和溶出速度的最佳方法的条件。方法：以聚乙烯吡咯烷酮（PVP）,聚乙二醇6000（PEG-6000）,PEG-6000与Tween-80混合载体。制备固体分散体;以β-CD,HP-β-CD制包合物,测定溶解度及体外溶出速度,结果：水中溶解度PVP固体分散体大于包合物,载体比例越大,药物溶出愈快。比例相同时,PVP固体分散体溶出最快。结论：PVPK30作为水飞蓟素固体分散体的载体。载药量大。增溶效果显著。     

桂利嗪-聚乙二醇固体分散体的制备及体外溶出实验

目的：应用固体分散技术提高难溶性药物桂利嗪的溶解度和体外溶出速率。方法：采用溶剂-熔融法制备桂利嗪-聚乙二醇（PEG6000）固体分散体，并进行体外溶出度研究。结果：桂利嗪-聚乙二醇固体分散体的水中溶解度和体外溶出度高于原药，且载体加入量越大，溶出越快；比例相同的固体分散体的溶出度明显高于其物理混合物。结论：本实验所制备的桂利嗪-聚乙二醇固体分散体能加速体外溶出和增大溶解度。     

卡维他洛固体分散体的研制及其体外溶出实验

目的：制备卡维他洛固体分散体,增加其溶解度和溶出速度。方法：以聚乙烯吡咯烷酮（PVP）、聚乙二醇-6000（PEG-6000）为载体,溶剂法和溶剂熔融法制备固体分散体,并进行体外溶出度研究。结果：载体比例越大,药物溶出愈快;且载体比例愈小,差异愈显著。载体为PVP所制固体分散体的体外溶出行为总体优于载体为PEG-6000的固体分散体。结论：本试验所制卡维地洛固体分散体能加速体外溶出,为难溶于水药物提高生物利用度开辟一条途径。     

卡维地洛固体分散体的制备及其体外溶出度的测定

目的 :制备卡维地洛固体分散体 ,提高其溶解度和溶速率。方法 :以聚乙烯吡咯烷酮 (PVP)、聚乙二醇 -6000(PEG -6000)为载体 ,以溶剂法和熔融法制备固体分散体 ,并进行体外溶出度研究。结果 :载体比例越大 ,药物溶出愈快 ;载体比例愈小 ,差异愈显著。载体为PVP所制固体分散体的体外溶出行为总体优于载体为PEG -6000的固体分散体。结论 :本试验所制卡维地洛固体分散体能加速体外溶出 ,提高生物利用度 ,可用于制备高效制剂     

依托泊苷固体分散体的制备及体外研究

目的 制备依托泊苷固体分散体，改善依托泊苷的溶出度。方法 应用聚乙烯吡咯烷酮（PVPK30）和聚乙二醇（PEG6000）为载体，以溶剂法制备固体分散体。采用正交实验设计考察制备固体分散体的最佳工艺条件，并对所得样品进行体外溶出度研究，以X线衍射、DSC-量热分析进行物相鉴定。结果 依托泊苷在载体PVPK30和PEG6000中结晶消失。药物的溶出速度随载体比例增加而增加。结论 采用PVPK30和PEG6000所制依托泊苷固体分散体能显著提高药物的体外溶出度，药物以无定形状态或分子态存在于载体中。     

洛伐他汀固体分散体的制备及体外溶出特性比较

目的：利用固体分散技术制备洛伐他汀固体分散体，增加其溶出速率。方法：以不同比例的聚乙烯吡咯烷酮（PVPk-30）、聚乙二醇6000（PEG6000）为载体，采用溶剂法和熔融法制成洛伐他汀固体分散体，测定其溶出速率，并采用差示扫描量热（DSC）法、显微照相技术鉴别药物在固体分散体中的存在状态。结果：两种固体分散体均能提高洛伐他汀溶出速率，在药物载体比例大于1：5时效果较好；洛伐他汀固体分散体中晶型消失，分散在载体中。载体为PVPK30所制固体分散体的溶出速率总体优于载体PEG6000。结论：固体分散体能加速洛伐他汀溶出速率。     

冬凌草甲素固体分散体的制备及溶解性能研究

目的采用固体分散技术,提高冬凌草甲素的体外溶解性能。方法分别以聚乙二醇6000（PEG6000）、聚乙烯吡咯烷酮K30（PVPK30）为载体,制备冬凌草甲素固体分散体。采用紫外分光光度法进行含量测定,差示热分析法鉴别药物在载体中的存在状态,并进行溶解度、体外溶出速率实验。结果两种载体的固体分散体均能增加药物的溶解度和溶出速率,冬凌草甲素在载体中以高度分散状态存在。结论以PVPK30为载体制备的冬凌草甲素固体分散体体外溶解度和溶出速率明显提高。     

阿西美辛固体分散体的制备和溶出度测定

目的:利用固体分散技术制备阿西美辛固体分散体,增加其溶解度和溶出速度.方法:以聚乙烯吡咯烷酮(PVP)、聚乙二醇-6000(PEG-6000)、聚乙二醇-12000(PEG-12000)为载体,溶剂法和溶剂熔融法制成阿西美辛固体分散体,并进行体外溶出度研究.结果:载体比例越大,药物溶出越快;且载体比例越小,差异越显著.载体为PVP所制固体分散体的体外溶出总体优于载体为PEG-6000和PEG-12000的固体分散体.结论:固体分散体能加速阿西美辛体外溶出.     

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.     

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.     

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.