法莫替丁分散片的崩解和溶出度研究

采用全粉末直接压片法制备法莫替丁分散片。分散片在水中和口腔中迅速崩解和分散。分散片硬度相对较低（3．0－7．5kg）时,硬度变化对崩解和溶出度没有影响。硬度超出此范围时,硬度越大,崩解时间越长而溶出越迟缓。溶出度实验结果表明该分散片在水和0．1mol/L盐酸溶液中溶出速度明显较市售片快。     

复方盐酸小檗碱分散片的制备及其溶出度考察

目的 制备复方盐酸小檗碱分散片,并与市售片剂的溶出度进行比较。方法以微晶纤维素为填充剂,交联聚乙烯吡咯烷酮为崩解剂,湿法制粒制备分散片。制定质量标准和溶出度测定方法,并进行质量评价和溶出度比较。结果符合中国药典中有关分散片的要求,其体外溶出释药明显优于普通片。结论所制分散片处方合理,崩解快、溶出快而完全。     

阿西美辛分散片的制备及其溶出度评价

目的:制备阿西美辛分散片,并对其进行体外溶出度评价。方法:以阿西美辛为主药,微晶纤维素(MCC)为填充剂,采用湿法制粒法制备片剂;取MCC、羧甲基淀粉钠(CMS-Na)的处方用量及羟丙基甲基纤维素(HPMC)的浓度为因素,崩解时限为指标筛选处方;采用《中国药典》溶出度法第二法,以磷酸盐缓冲液为介质进行体外溶出度考察。结果:最佳处方为MCC 40%、CMS-Na 5%、HPMC 1%;所制片剂呈淡黄色、片面光洁,崩解时限20s,含量、分散均匀性均符合2010年版《中国药典》相关要求;30min内溶出度大于90%。结论:该制剂制备方法简单,分散片溶出速度快且完全。     

桂利嗪分散片处方工艺研究及溶出度考察

目的：制备桂利嗪分散片并考察处方工艺与体外溶出度。方法：采用正交设计表L9(3^4)筛选处方，选用转篮法进行溶出度考察，溶出量采用紫外分光光度法测定。结果：分散片崩解时间小于3min，分散后的溶液能通过710μm筛网，溶出参数分别为：T50=0．33min．Td=0.60min，T80=1.36min。结论：桂利嗪分散片质量能达到中华人民共和国药典2000年版要求，分散片的溶出速度明显快于市售片。     

麝香保心分散片的制备和冰片的体外溶出度研究

为制备麝香保心分散片和考察冰片的体外溶出度，以交联聚乙烯吡咯烷酮为崩解剂，微晶纤维素为填充剂，羧甲基纤维素钙为溶胀性辅料、1%羟丙基甲基纤维素水溶液为粘合剂，制备麝香保心分散片；采用气相色谱法以冰片为测定指标。考察其体外溶出度。结果表明，按最佳工艺制备的麝香保心分散片在20&;#177;1℃水中于15s内可完全崩解且分散均匀，冰片溶出的T50值为2.02min。结论：麝香保心分散片遇水崩解迅速，指标性成分冰片的溶出速率明显高于麝香保心丸。     

盐酸伐昔洛韦分散片的研制

目的: 制备盐酸伐昔洛韦分散片,并测定其溶出度.方法: 采用微晶纤维素、羧甲基淀粉钠、交联PVP等辅料制备分散片,制定溶出度测定方法,并对其进行质量评价和溶出度比较.结果: 用所筛选处方制备的分散片符合英国药典中有关分散片的要求,制剂质量可控,溶出度优于普通片.结论: 筛选的处方合理,制备的盐酸伐昔洛韦分散片比市售片崩解快、分散度均匀性好,溶出快而完全.     

替米沙坦分散片的制备及质量控制

目的：制备替米沙坦分散片，建立替米沙坦分散片的溶出度测定法。方法：采用正交试验，以崩解时间为指标，以羧甲淀粉钠与微晶纤维素的用量、葡甲胺的用量为3个因素，分别设计3个水平优化分散片的处方，采用桨法对自制的分散片与进口普通片进行了溶出度测定，比较研究二者的溶出度Weibull分布参数。结果：替米沙坦分散片工艺简单，在1min内全部崩解，溶出速率明显优于进口普通片，符合分散片的各项质量指标。结论：用优化处方制备的替米沙坦分散片体外溶出特性明显优于普通片。     

氟伐他汀钠分散片的制备

目的制备氟伐他汀钠分散片。方法以崩解时间为指标,采用正交设计试验,对氟伐他汀钠分散片处方进行筛选。结果乳糖、微晶纤维素(MCC)各40%为填充剂,MCC、羧甲基淀粉钠(CMS-Na)5%和低取代羟丙基纤维素(LS-HPC)10%为崩解剂,湿法制粒制备分散片。进行了溶出度实验。符合中国药典中有关分散片的要求。结论所制分散片处方合理,崩解快、溶出快而完全。     

倍他环糊精卡马西平分散片溶出试验

采用倍他环糊精包合技术及低取代羟丙基纤维素为崩解剂 ,将卡马西平制成分散片 ;结果显示 :由包合物制成的分散片的溶出度比卡马西平普通片显著增加 ,90 %药物在 3min内溶出。     

双氯芬酸钾分散片的研制及体外溶出度测定

目的 研制双氯芬酸钾分散片并考察其体外溶出特性。方法 对处方中粘合剂、填充剂、崩解剂及其用量进行筛选，比较分散片及普通片的溶出度。结果 以10％聚乙烯吡咯烷酮（PVP）为粘合剂，微晶纤维素和乳糖为填充剂，10％速崩王为崩解剂，采用内外加法制得的双氯芬酸钾分散片，在1min内完全崩解。结论 采用优化处方制备的双氯芬酸钾分散片的体外溶出特性优于普通片。     

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.     

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.