尼莫地平缓释胶囊的释放度与其普通片的溶出度比较

目的 在相同介质中将尼莫地平缓释胶囊的释放度与普通片的溶出度作比较。方法 利用ZRS-8C型药物智能释放仪,采用转篮法,溶出介质为0.55%的十二烷基硫酸钠水溶液,溶出杯内温度为(37±0.5)℃,转速为50±1r/min,分别在不同的时间点取样,在波长为360nm处测定吸收度,计算出释放度和溶出度。结果 尼莫地平缓释胶囊在60min的累积释放率为44.17%,而普通片的累积溶出率达到了90.91%。结论 尼莫地平缓释胶囊与普通片相比,血药浓度明显平稳,从而使药效延长,达到了提高人体生物利用度的目的。     

国产尼莫地平片的溶出度比较

目的:比较国内不同药厂尼莫地平片剂的溶出情况。方法:参照日本在"药品品质再评价"拟定流程中对溶出度试验条件的规定,分别考察不同批次尼莫地平片在水、pH1.2人工胃液、pH4.0醋酸盐缓冲液、pH6.8磷酸盐缓冲液4种溶出介质中的体外溶出行为,溶出方法采用桨法,转速为50r·min~(-1),同时和中国药典2005年版规定的尼莫地平片溶出方法进行比较。结果:按照中国药典方法进行溶出时,14个药厂的尼莫地平在6h内溶出均超过80%;在其他介质中溶出时,只有1家药厂的产品能够在6h溶出超过70%,其他药厂产品均不太满意。结论:同一批尼莫地平片在不同溶出介质中溶出差异很大;不同药厂尼莫地平片剂的质量有显著性差异,国产药品的质量亟待提高。     

光纤传感系统在线监测不同厂家尼莫地平片溶出度

目的:使用光纤药物溶出度实时测定仪FODT-601,实时监测国内6个不同厂家尼莫地平片的溶出度曲线,以评价其工艺质量.方法:设定测定波长238 nm、基准校正波长550 nm、温度37℃、转速75 r·min-1、数据采集间隔时间30 s、监测时间30 min,以900 mL 醋酸盐缓冲液(pH4.5;含0.3%十二烷基硫酸钠)为溶出介质,桨法,用光程为2 mm的光纤探头监测尼莫地平片的溶出曲线.结果:6个不同厂家尼莫地平片的溶出度均符合<中国药典>规定,但各溶出曲线存在差异.结论:光纤药物溶出度实时测定仪准确、连续、定量地反映了药物的溶出过程,获得的数据信息更加完整、真实,可比较出不同厂家之间同种药品的溶出过程差异.     

尼莫地平缓释胶囊的释放度与其普通片的溶出度比较

目的　在相同介质中将尼莫地平缓释胶囊的释放度与普通片的溶出度作比较。方法　利用ZRS 8C型药物智能释放仪 ,采用转篮法 ,溶出介质为 0 5 5 %的十二烷基硫酸钠水溶液 ,溶出杯内温度为 ( 37± 0 5 )℃ ,转速为 5 0± 1r/min ,分别在不同的时间点取样 ,在波长为 36 0nm处测定吸收度 ,计算出释放度和溶出度。结果　尼莫地平缓释胶囊在 6 0min的累积释放率为 4 4 17% ,而普通片的累积溶出率达到了 90 91%。结论　尼莫地平缓释胶囊与普通片相比 ,血药浓度明显平稳 ,从而使药效延长 ,达到了提高人体生物利用度的目的     

交联聚维酮粒度对尼莫地平片溶出度的影响

目的探讨不同粒度交联聚维酮(Polyplasdone)对尼莫地平片溶出度的影响。方法采用不同粒度的交联聚维酮制备尼莫地平片,用紫外分光光度法测定溶出度。结果采用不同粒径的交联聚维酮制备尼莫地平片其溶出度相差甚远,其中粒径在125~74μm范围内的交联聚维酮生产出的尼莫地平片溶出效果最好,30min溶出度为95.74%。结论粒度在125~74μm范围内的交联聚维酮生产出的尼莫地平片体外溶出度最高。     

依西美坦片在不同介质中的溶出特性

目的:考察新药依西美坦片在3种不同介质中的溶出特性,以研究影响其口服吸收速率的主要因素和规律。方法:建立HPLC法检测其制剂含量和溶出液浓度,色谱柱:HypersilC18(150mm×4.6mm,5μm);流动相:甲醇:0.05mol/LKH2PO4溶液(60:40);检测波长:247nm。溶出介质选用水、0.1mol/L盐酸溶液及0.5%十二烷基硫酸钠溶液,采用转篮法,转速100r/min。结果:依西美坦片在水和0.1mol/L盐酸溶液中的溶出较差,在0.5%十二烷基硫酸钠溶液巾溶出迅速完全,60min时在3种介质中的溶出百分率分别为(60.25±3.76)%、(47.57±1.20)%和(82.24±0.96)%。结论:依西美坦片可能主要在肠道溶出,其溶出速率受介质影响大。     

国产尼莫地平片与原研制剂体外溶出度比较

目的考察国内9个厂家生产的尼莫地平片与原研制剂(商品名:尼膜同)的体外溶出度,比较体外溶出行为,为临床选择用药及控制国产尼莫地平的质量提供理论依据。方法采用高效液相色谱法测定尼莫地平片分别在纯化水(质量分数0.3%SDS)、p H值1.2氯化钠盐酸溶液(0.3%SDS)、p H值4.5醋酸盐缓冲液(0.3%SDS)和p H值6.8磷酸盐缓冲液(0.3%SDS)共4种溶出介质中的溶出度,并用f2相似因子法评价溶出曲线的相似性。结果只有一个厂家生产的尼莫地平片在4种溶出介质中f2相似因子大于50,与原研制剂相似;其余厂家生产的尼莫地平片在4种溶出介质中溶出行为与原研制剂不相似。结论多数国产的尼莫地平片与原研制剂溶出过程存在显著性差异,临床应用时应加以注意。厂家应积极改进现有工艺,严格控制药物的溶出速率。     

国产与进口尼莫地平片的溶出度考察

目的:考察国产与进口尼莫地平片的溶出度,为控制国产制剂质量提供依据。方法:参考2005年版《中国药典》相关标准,利用光纤药物溶出度实时测定仪绘制实时溶出曲线,对国产(B、C、D、E)与进口(A)5厂家共5批次尼莫地平片进行考察。结果:5厂家尼莫地平片30min时的溶出度均符合2005年版《中国药典》的规定,其平均累积溶出百分率均在89以上;但溶出速率明显不同,在6min时A、B、C、D、E5厂家产品平均累积溶出百分率分别为29.22、46.83、55.10、71.84、45.72。结论:国产与进口尼莫地平片的溶出过程存在差异,国产厂家应积极改进现有工艺,严格控制药物的溶出速率。     

拉呋替丁片溶出度测定方法研究

目的 建立拉呋替丁片溶出度的测定方法.方法 溶出方法采用中国药典溶出度第三法,以盐酸溶液(9→1 000)为溶出介质,转速为50 r·min-1,测定方法采用高效液相色谱法,用十八烷基硅烷键合硅胶为填充剂;以甲醇 1%醋酸铵溶液(冰醋酸调节pH值为5.7)(40∶60)为流动相;检测波长为279 nm,进样量 20 μl.结果 拉呋替丁在5～500 mg·L-1内呈良好的线性关系(r=0.999 8),RSD为0.47%(n=6).绘制的溶出曲线表明 30 min内拉呋替丁片可溶出 80%以上,确定的溶出时间为 30 min,限度为 80%.结论 该方法简单快速,准确稳定,可用于拉呋替丁片溶出度.     

不同厂家替米沙坦制剂的体外溶出度比较

目的 比较不同厂家生产的替米沙坦片或胶囊在不同溶出介质中的体外溶出度。方法 按中国药典2010版采用紫外分光光度法,以1 000 mL不同溶液为溶出介质,转速50 r·min^-1,温度(37±0.5)℃,测定不同厂家的6个品种的替米沙坦片剂或胶囊的体外溶出度。结果 在pH 7.5磷酸盐缓冲液中,30 min的累积溶出量均超过标示量的85%;而在0.1 mol·L-1盐酸中,只有R片剂(Micardis)30 min的累积溶出量>80%,其中C和D在60 min的累积溶出量<30%,D片30 min的溶出度<10%。结论 各生产厂家应严格控制产品内在质量,保证临床用药安全有效。     

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.