HPLC法测定奥美拉唑碳酸氢钠氢氧化镁片溶出度

目的:建立奥美拉唑碳酸氢钠氢氧化镁片溶出度测定方法.方法:以水为溶出介质,采用高效液相色谱法测定奥美拉唑碳酸氢钠氢氧化镁片的溶出度.结果:奥美拉唑线性方程为A =5.45×105C -7.58×104 (r =0.999 9)线性范围:4.0～40.0μg·ml-1.平均回收率为99.86％;RSD为0.42％.结论:本法可用于奥美拉唑碳酸氢钠氢氧化镁片溶出度测定.     

盐酸黄连素肠溶微囊的制备及评价

目的：以聚丙烯酸树脂Ⅱ号为囊材，制备盐酸黄连素肠溶微囊，并测定其体外溶出度。方法：采用溶剂挥发法制备盐酸黄连素肠溶微囊，通过正交实验进行优化，以微囊的包封率及栽药量为指标。结果：应用优化工艺制备的盐酸黄连素肠溶微囊，栽药量为11．18％，包封率为85．00％，盐酸黄连素肠溶微囊在pH为6．8、7．4的溶出介质中60min内溶出度超过70％。结论：采用溶剂挥发法制备盐酸黄连素肠溶微囊，工艺稳定可靠，操作简便，栽药量高，具有肠溶特性，显示出良好的应用前景。     

依托红霉素片制备工艺优化的研究

目的考察依托红霉素片溶出的影响因素,优化处方工艺,提高依托红霉素片的溶出度。方法通过影响因素试验考察优化工艺与原工艺的含量变化;采用正交试验法优选崩解剂的用量,崩解剂的类型、片剂的硬度。结果碳酸氢钠能显著提高依托红霉素片的溶出度。结论优化的工艺质量稳定,重现性良好。     

硝苯地平片体外溶出特性的研究

目的：提高硝苯地平片的体外溶出速率。方法：分别考察药物粒度、稀释剂、崩解剂对体外溶出度的影响，比较溶出特性曲线筛选处方。结果：用优选处方制备的硝苯地平片溶出良好，达到中国药典2000版规定。结论：该片剂处方合理，制备工艺简单易行，适合工业化生产。     

特非那定片的溶出度研究

目的：改进特非那定片的处方工艺,改善溶出度。方法：参照国外处方并根据国内辅料情况筛选新的片剂工艺方法。将不同处方生产的片剂按《中国药典》规定的方法进行溶出度检查。结果：按新处方、老处方生产的片剂与德国史达特公司生产的片剂在４５分种时的溶出分别为８９．０２％、１０．８１％和８２．３６％。结论：特非那定片处方组成对溶出度尤为重要,新处方中碳酸氢钠的加入使其溶出度明显提高。     

难溶性药物兰索拉唑口服结肠定位片的制备及体外释药性

目的制备难溶性药物兰索拉唑结肠靶向(Lansoprazole colon-targeted,LPZ-CT)片并考察处方及释放条件对片剂释药行为的影响。方法湿法制粒压片得兰索拉唑速释片芯,采用喷雾包衣与压制包衣结合的方法制备pH与酶双重敏感的LPZ-CT片。结果速释片芯体外溶出度达70%以上。当pH层包衣增重为7%,压制包衣层含20%瓜尔胶时,LPZ-CT片在模拟胃、小肠环境的介质中不释药,在模拟结肠环境介质(pH7.4,0.2 g.L-1β-甘露聚糖酶)中,累积释放度达80%以上。结论LPZ-CT片体外实验满足药物溶出和精确定位结肠的要求。     

盐酸小檗碱微囊的制备及溶出度测定

以聚丙烯酸树脂Ⅳ为囊材,采用液中干燥法制备盐酸小檗碱微囊,以药物的溶出度试验评价药物在不同pH介质中的溶出情况.结果表明,盐酸小檗碱微囊在水中几乎不溶出,而在酸性介质(pH1.0～3.0)中,则快速溶出.     

阿魏酸钠滴丸的制备及溶出度测定

目的：通过固体分散技术制备滴丸，以提高阿魏酸钠的溶出度。方法：以聚乙二醇（PEG）6000、泊洛沙姆188为载体基质制备滴丸，HPLC法测定含量，转篮法考察溶出度。结果：滴丸中PEG6000／药物比值越大．阿魏酸钠溶出越快；所制得滴丸外观圆整，质地均匀；分别以0．1mol／L盐酸溶液、水、pH6,8磷酸盐缓冲液为溶出介质，阿魏酸钠滴丸均较市售片显著增加溶出度。结论：阿魏酸钠滴丸具有良好的速释效果。     

尼莫地平固体分散体在速释制剂中的溶出性质(英)

为了提高难溶性药物尼莫地平的溶出度,并在此基础上研制出其速释制剂,本研究选用PVP（k30）为载体制备了尼莫地平的固体分散体及机械混合物,比较了二者体外药物溶出度及药物的结晶形态,并考查了共沉淀物的稳定性。进而进行了尼莫地平速释片剂处方的筛选,并按最优处方制备了胶囊剂。比较了自制速释胶囊剂与市售片剂的释药情况。体外实验结果表明,固体分散体对尼莫地平溶出度的提高大大优于机械混合物,5分钟的释药量,前者为89％,而后者仅为45％。X-射线衍射实验表明,尼莫地平在以PVP为载体的固体分散体中是以非晶体形式存在,并且在室温并密封于玻璃瓶中放置一年后仍无结晶出现。本研究制备的片剂和胶囊剂都具有速释性质,而以胶囊剂为优,说明压片压力可能影响溶出。速释胶囊的释药速率大大高于市售普通片剂。     

米氮平口崩片的制备及初步稳定性考察

目的：采用正交试验筛选米氮平口崩片的处方,并进行初步稳定性考察。方法：以甘露醇（ A）、微晶纤维素（ B）、低取代羟丙基纤维素（ C）及交联聚乙烯吡咯烷酮（ D）用量为考察因素,以崩解时间、溶出度为评价指标进行正交试验,并采用相似因子（ f2）对自制片剂和原研制剂在溶出介质中的累积溶出度进行比较。通过高温,高湿,光照试验初步考察制剂稳定性。结果：A、B、C、D用量分别为70,20,2.5,10 mg时,制备的片剂外观光洁,崩解较快,溶出度高。自制片剂和原研制剂在溶出介质中的累积释放度f2为63.38。影响因素试验结果表明本品应防潮,避光保存。结论：米氮平口崩片处方设计合理,制备工艺可行,质量稳定。     

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.