硝苯地平片剂溶出度的考察

目的考察不同生产企业生产的硝苯地平片剂的体外溶出度。方法分别以0.1 mol.L-1盐酸溶液、人工胃液(不含胃蛋白酶)、pH 4.5醋酸钠缓冲液、pH 6.8磷酸盐缓冲液和蒸馏水为溶出介质,采用紫外分光光度法检查;以质量分数为0.25%十二烷基硫酸钠为溶出介质,采用HPLC法检查,比较不同厂家硝苯地平片剂的体外溶出度。用相似因子法评价硝苯地平片剂在0.1 mol.L-1盐酸溶液、人工胃液(不含胃蛋白酶)、pH 4.5醋酸钠缓冲液、pH 6.8磷酸盐缓冲液和蒸馏水中的溶出行为。结果在质量分数为0.25%十二烷基硫酸钠溶液中,硝苯地平的溶出度在60 min均大于65%,而在其他溶出介质中的溶出度均达不到《英国药典》及《美国药典》中规定的标准。相似因子f2均在50~100之间。结论溶出介质的pH值对硝苯地平的溶出度没有影响。从整体来看,国产硝苯地平片剂的体外溶出行为与国外制剂相比有很大差距。     

尼莫地平片剂及胶囊剂溶出度的考察

目的:比较六个厂家的尼莫地平片剂及胶囊剂的溶出度,从而考察其内在的质量。方法:按照中国药典2000年版二部附录中有关溶出度及分光光度法的规定,分别测定16批供试品在水、15％乙醇溶液、0.1 mol/L盐酸溶液、磷酸盐缓冲液(pH 6.8)4种溶出介质中的溶出度。结果:从16批供试品在水、15％乙醇溶液、0.1mol/L盐酸溶液、磷酸盐缓冲液(pH 6.8)4种溶出介质中的溶出度的结果,看尼达尔片在水、0.1mol/L盐酸溶液、磷酸盐缓冲液(pH6.8)3种溶出介质中的溶出度略高于进口产品,较明显高于其他国产品牌,在15％乙醇溶液的介质中,尼达尔片与其他5种样品的溶出量基本一致。结论:尼达尔片由于以特殊工艺方法制成,采用了先进的固体分散技术,使有效成分以分子状态进入载体网状骨架中,形成非结晶性无定形物,从而使溶出 度提高,使之在质量上与进口及国内其他产品相比占优势。     

氟康唑胶囊体外溶出度的质量评价

目的 比较氟康唑胶囊2个仿制厂家与原研制剂在3种溶出介质的溶出曲线,为评价氟康唑胶囊药品质量提供依据.方法 采用《中国药典》2010年版二部附录XC第一法的装置,测定了3个厂家氟康唑胶囊在0.1 mol/L盐酸溶液、水和磷酸盐缓冲液(pH6.8)中的溶出曲线,并用f2因子法进行比较分析.结果 在0.1 mol/L盐酸溶液和磷酸盐缓冲液(pH6.8)中,C厂家制剂与原研制剂的溶出曲线一致,B厂家制剂与原研制剂的溶出曲线有明显差异,但在水中仿制制剂与原研制剂的溶出曲线有明显差异,批内均一性的考察结果是C厂家优于B厂家制剂,B和C仿制厂家的批间重复性均良好.结论 作为氟康唑胶囊的溶出介质,水比0.1 mol/L盐酸溶液和磷酸盐缓冲液(pH6.8)对制剂质量具有更好的分辨能力,建议修订该溶出度检验方法的溶出介质,与原研药溶出曲线不一致的厂家,建议研究晶型或改进处方工艺.     

盐酸洛美沙星分散片体外溶出度测定方法的建立

目的:建立盐酸洛美沙星分散片体外溶出度的测定方法。方法:分别以水、磷酸盐缓冲液(pH6.8)、醋酸盐缓冲液(pH4.0)和盐酸溶液(0.1mol.L-1)为介质,篮法、转速100r.min-1条件下测定盐酸洛美沙星分散片在不同时间点的累积溶出率,采用紫外分光光度法在287nm波长下测定含量,确定溶出度的测定方法。结果:以盐酸溶液(0.1mol.L-1)为介质时,样品溶出更快、更平稳;确定溶出度检查取样时间为15min,限度标准为80%。结论:建立的盐酸洛美沙星分散片的体外溶出度测定方法可行。     

自制氨氯缬沙噻嗪片与Exforge HCT的体外溶出行为比较

测定了自制氨氯缬沙噻嗪片与原研制剂(Exforge HCT)在4种溶出介质(pH 6.8磷酸盐缓冲液、pH 4.5磷酸盐缓冲液、0.1 mol/L盐酸和水)中的溶出曲线,并进行相似性评价.结果表明,自制样品与原研制剂在4种溶出介质中溶出曲线相似因子f2大于50,差异因子f1小于15,表明两种制剂体外溶出行为相似.     

UV法测定盐酸二甲双胍肠溶胶囊酸中释放度方法的探讨

目的:建立盐酸二甲双胍肠溶胶囊释放度测定方法。方法:采用 UV 法测定盐酸二甲双胍肠溶胶囊在0.1 mol·L~(-1)盐酸溶液及 pH 6.8磷酸盐缓冲液中的释放度。结果:0.1 mol·L~(-1)盐酸溶液对释放度测定的影响较大,依现行药品标准直接测定,回收率仅为40.5%;我们将酸中释放液用0.2 mol·L~(-1)磷酸钠溶液调 pH 约6.8后测定,回收率为100.3%。结论:现行药品标准中盐酸二甲双胍肠溶胶囊酸中释放度测定方法不合理,须进行调整。     

国产盐酸左氧氟沙星片的溶出度比较

目的:对25批国产盐酸左氧氟沙星片的溶出情况进行比较.方法:采用<中国药典>2010年版方法,对25批不同厂家的片剂在水、pH6.8磷酸盐缓冲液、pH4.5磷酸盐缓冲液、0.1mol/l盐酸溶液中的溶出行为进行测定,并比较相似因子.结果:盐酸左氧氟沙星片剂在不同溶剂中的溶出行为不同.结论:不同厂家生产的制剂质量存在差异...     

心力衰竭患者QRS时限与血浆脑钠肽相关分析

目的考察3个厂家厄多司坦胶囊的体外溶出度,为临床用药提供参考。方法分别以水、盐酸溶液(pH=1.0)、磷酸盐缓冲液(pH=5.8)及磷酸盐缓冲液(pH=6.8)为介质,测定样品累积溶出度,并选择相似因子f2法判定溶出曲线的相似性。结果 3个厂家厄多司坦胶囊在各介质条件下的溶出曲线均具有相似性,且15 min内的溶出均超过85%。结论 3个厂家厄多司坦胶囊体外溶出无显著性差异,均具有快速、均一、良好的溶出行为。     

国产、进口及国外三种吗替麦考酚酯胶囊的体外溶出曲线对比研究

目的通过建立有区分力的溶出曲线测定方法,对国产、进口原研及美国橙皮书收载的参比制剂三种吗替麦考酚酯胶囊进行体外溶出曲线的对比研究,以评价国产制剂、进口及国外原研参比制剂溶出行为的一致性。方法参考美国FDA溶出曲线数据库、日本IF文件及中国药典公布的吗替麦考酚酯胶囊溶出检测条件,选择0.1 N HCl、水、pH6.8磷酸盐缓冲液和pH5.0柠檬酸缓冲液4种不同pH值的溶出介质,对国内外上市的三种吗替麦考酚酯胶囊溶出曲线进行对比研究,通过相似因子(f2)法对溶出曲线进行评价。结果三种制剂在0.1 N HCl介质中15 min累计溶出量均大于85%;国产制剂与国内外参比制剂在水、pH6.8磷酸盐缓冲液和pH5.0柠檬酸缓冲液三种溶出介质中的溶出曲线相似因子f2均大于50。结论国产制剂、进口及国外三种制剂在4种不同溶出介质中的溶出曲线均一致。     

泮托拉唑钠肠溶微丸的制备

以泮托拉唑钠、羟丙甲纤维素、无水碳酸钠、吐温-80、十二烷基磺酸钠和水混合制成主药层包衣溶液.采用流化床包衣技术,对空白丸芯依次包主药层、隔离层和肠溶层,制得泮托拉唑钠肠溶微丸,并优化了处方和工艺.将所得肠溶微丸装入普通胶囊中制成泮托拉唑钠肠溶微丸胶囊,3批制品在pH 6.8磷酸盐缓冲液中45 min时的释放度分别为(97.6±1.1)%、(98.1±1.3)%、(98.4±1.9)%,在0.1 mol/L盐酸中2h时的释放量分别为(2.9±1.7)%、(2.9±1.4)%、(2.3±2.1)%.     

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.