磷酸淀粉对片剂崩解度和溶出度的作用

本文测定了磷酸淀粉(交联淀粉)的松密度、流动性、吸湿性,并与玉米淀粉、低取代羟丙基纤维素及羧甲基淀粉进行比较。结果交联淀粉的松密度和流动性最大,吸湿性与玉米淀粉相近。交联淀粉能促进磺胺嘧啶、阿司匹林,扑热息痛片剂的崩解和溶出,但作用一般不如羧甲基淀粉,有时接近于低取代羟丙基纤维素。     

一些常用片剂填充剂与崩解剂的性能比较

以碳酸钙为模型药物 ,以抗张强度、崩解时间为指标比较了 4种填充剂 (玉米淀粉、糊精、微晶纤维素、可压性淀粉 )的压缩成形性及 8种崩解剂 (微晶纤维素PH3 0 1、PH3 0 2、可压性淀粉、交联羧甲基纤维素钠、交联聚乙稀吡咯烷酮、干淀粉、羧甲基纤维素钙、低取代羟丙基纤维素 )的崩解性。结果表明 ,可压性淀粉的压缩成形性优于其他 3种填充剂 ,占主药量 5 %时的抗张强度达到1 62MPa,此时糊精、微晶纤维素、玉米淀粉的抗张强度分别为 1 4 6MPa、1 1 6MPa、0 65MPa;吸水膨胀性较强的交联聚乙烯吡咯烷酮、交联羧甲基纤维素钠、干淀粉及羧甲基纤维素钙的崩解效果较好 ,采用不同填充剂时的崩解时限均在 2min内     

甲壳素在中药片剂中的崩解性能考察

本文以甲壳素为崩解剂制备肝炎宁和穿心莲浸膏片，并与以淀粉、羧甲淀粉钠、低取代羟丙基纤维素及微晶纤维素为崩解剂的片剂进行比较．结果表明：甲壳素的崩解性能优于上述４种崩解剂．     

提高灰黄霉素片溶出度的处方工艺改进

以玉米淀粉为稀释剂,低取代羟丙基纤维素为崩解剂,采用羧甲基纤维钠水溶液为粘合剂,制成的灰黄霉素片快速崩解和溶出,溶出度增大。     

扑热息痛片辅料选择的实验研究

扑热息痛片处方中加入碳酸钙、低取代羟丙基纤维素或羧甲基淀粉可以加快片剂的崩解、溶出,提高其生物利用度。     

国产羧甲基淀粉钠的崩解性能考查

作为崩解剂,羧甲基淀粉钠所制备的磺胺嘧啶、阿司匹林、Al(OH)_3片剂同淀粉、L-HPC、MCC、CMC-Na者进行了比较,其崩解性能和颗粒吸水膨胀性能都优于后四者。置换度在1.66～4.3%(含钠量,合成以水为介质)和1.99～5.21%(含钠量,合成以醇为介质)的羧甲基淀粉钠的崩解性能好。高聚合度的产品的崩解性能优于低聚合度者,羧甲基淀粉优于羧甲基淀粉钠,而且羧甲基淀粉钠的崩解性能与崩解介质的pH无关。     

速崩钙片剂的研究

为了制得崩解迅速 ,吸收良好的钙制剂 ,利用化学反应的方法制得粒径为 0 1～ 2 0 μm的碳酸钙 ,并对羧甲基淀粉钠、羧甲基纤维素钙、可压性淀粉和交联羧甲基纤维素钠四种崩解剂的性质进行考察 ,选择了崩解性能良好的羧甲基淀粉钠和交联羧甲基纤维素钠作为崩解剂 ,将其制成片剂。片剂崩解时间可达 45s     

羧甲基淀粉的干法制备

不用传统的醇/水工艺,而用干法合成片剂崩解剂羧甲基淀粉(CMS),节约了乙醇,并探索反应条件对 CMS 吸水溶胀性能和崩解性能的影响。     

羟甲基淀粉钠作为粘合剂对片剂崩解和溶出的影响

实验考查了羧甲基淀粉钠(CMS-Na)作为粘合剂对磺胺嘧啶、阿司匹林片剂的崩解和溶出度的影响,并与羟丙基甲基纤维素、明胶和淀粉浆做了比较。CMS-Na干粉用喷水法制软材所制成的片剂其崩解和溶出度优于用羟丙基甲基纤维素、明胶和淀粉浆以传统湿法制备者。片剂崩解后的粒度分布测定表明,片剂溶出度主要与崩解时间显著相关。     

卡马西平片制备工艺研究

以低取代－羟丙基纤维素（Ｌ－ＨＰＣ）作崩解剂,考察了Ｌ－ＨＰＣ用量、加入方法１粘合剂种类、卡马西平粉末粒度及其他辅料对卡马西平片制备工艺及溶出度的影响,结果表明,用Ｌ－ＨＰＣ作崩解剂,用量为片重的１０％,采用内外混合加入法,用６．５％淀粉浆作粘合剂,卡马西平过１２０目筛,制得的卡马西平片硬度较好,外观光洁,溶出度可达９０％以上。     

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.     

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.