盐酸二甲双胍缓释片处方筛选及工艺研究

对盐酸二甲双胍缓释片的处方及工艺进行筛选和研究。方法：根据释放度作为判断原则，对缓释骨架材料、填充剂、粘合剂、润滑剂及包衣材料的种类、规格、用量及工艺等进行了考察，并在此基础上采用正交试验1．9(3^4)方案对处方进行筛选。结果：以HPMC K100M及HPMC K15M作为盐酸二甲双胍缓释片的基本骨架材料，微晶纤维素作为填充剂，硬脂酸镁为润滑剂，4％HPMCE5的70％乙醇溶液适量作为粘合剂制成片芯，采用薄膜包衣法，以欧巴代的70％乙醇溶液作为薄膜包衣材料，制得盐酸二甲双胍缓释骨架片。结论：本制剂工艺简单，所用各种辅料均为国产化，成本低，制得盐酸二甲双胍缓释片释放度符合规定。     

盐酸吡格列酮缓释片处方筛选及工艺研究

目的:对盐酸吡格列酮缓释片进行处方筛选及工艺研究。方法:通过测定不同时间吡格列酮在pH6.8磷酸盐缓冲液中的累积释药率,对缓释骨架材料、填充剂、黏合剂的种类或规格、用量及工艺等进行考察,确立片芯处方及制备工艺。结果:片芯处方以羟丙基甲基纤维素(HPMC)(K15M)为骨架材料,微晶纤维素为填充剂,2%HPMC(E5)的70%乙醇溶液为黏合剂;制备工艺采用薄膜包衣法,以欧巴代的70%乙醇溶液作为薄膜包衣材料;所制3批样品12h的累积释药率均在90%以上。结论:本制剂工艺简单,符合缓释制剂要求。     

维生素B1缓释片的制备工艺研究

摘 要 目的：筛选维生素B1（VB1）缓释片的最佳处方及制备工艺。方法: 采用单因素试验对填充剂的种类、骨架材料羟丙基甲基纤维素（HPMC）的型号及用量、阻滞剂的种类及用量、片重及片芯硬度进行考察,并采用正交试验对骨架材料HPMC的用量、阻滞剂乙基纤维素（EC）的用量及片芯硬度进行考察。结果: 确定最佳处方工艺为： HPMC K15M用量占片重50%,EC用量占片重20%,填充剂为乳糖,片重为200 mg,压制片芯硬度为50 N。结论:所制备的VB1缓释片缓释效果显著,为其新剂型的开发提供了理论参考和试验基础。     

拉莫三嗪缓释片的制备及体外释放行为考察

目的:改进原研制备工艺,仿制拉莫三嗪缓释片,并考察其体外释放行为。方法:采用羟丙基甲基纤维素(HPMC)E4M CR和HPMC K100LV CR制备缓释骨架片芯,以尤特奇~?L30D-55为肠溶材料包衣,制备拉莫三嗪缓释片。以与原研制剂体外释放度的相似因子f_2为指标,采用单因素法筛选处方中乳糖用量、HPMC E4M CR和HPMC K100LV CR质量比、HPMC用量及包衣增质量。结果:片芯处方为拉莫三嗪50 mg、HPMC K100LV CR 40 mg、HPMC E4M CR 61.4 mg、乳糖128 mg,最佳包衣增质量为3%。自制制剂和原研制剂在含0.5%十二烷基硫酸钠的pH 6.8磷酸盐缓冲液、pH 4.5乙酸-乙酸钠缓冲液和水中的体外释放行为均相似。结论:成功仿制了拉莫三嗪缓释片,且工艺比原研制剂更加简单、易行。     

五加生化缓释片的制备及体外释放度的研究

目的：筛选五加生化缓释片的最佳制备工艺,并进行体外释放度研究。方法采用正交试验法筛选处方;以羟丙甲基纤维素（HPMC）为骨架材料,制备五加生化缓释片,并对优化的试验结果进行体外释放效果考察。结果最优处方为HPMC K100M为骨架材料,70%乙醇为黏合剂,MCC为填充剂用量40 mg,淀粉为填充剂用量50 mg,采用最佳工艺制备的五加生化缓释片体外释放性能较好,HPMC的规格对药物的释放影响最大。结论本法制备的缓释片比普通片具有明显的缓释作用。该制备工艺简单易行,生产成本低,片剂外观及可压性良好。     

尼美舒利缓释片的制备与体外释放度考察

目的考察制备尼美舒利骨架缓释片的最佳缓释材料、缓释材料含量和制片压力。方法采用正交实验,从片剂外观、释放度确定缓释片处方和工艺。结果通过指标评价体系比较3种缓释材料［羟丙基甲基纤维素（HPMC）、 kollidon和卡波姆］的性能,其中kollidon压片性能最佳,片剂外观完整光滑,指标得分均达12分（总15分）,HPMC缓释性能最佳。通过最佳处方和工艺制得的3批骨架片外观完整光滑,缓释片释放行为最接近Higuchi释放,12 h平均累积释放达96.05%。结论该制备工艺简单可行。     

星点设计-效应面法优化复方氯雷伪麻缓释片的缓释片芯处方

目的:优化复方氯雷伪麻缓释片的缓释片芯处方。方法:以氯雷他定加入包衣层并包衣硫酸伪麻黄碱片芯制备复方氯雷伪麻缓释片。采用星点设计-效应面法优化硫酸伪麻黄碱片芯处方,以单硬脂酸甘油酯(GM)和羟丙甲纤维素(HPMC)K15M用量为考察因素,以硫酸伪麻黄碱1、6、12 h的累积释放度为指标,通过重叠等高线图确定优化处方,并进行处方验证。结果:氯雷他定与欧巴代包衣粉按1∶3比例混合包衣成为速释层;硫酸伪麻黄碱片芯作为缓释层,其处方为每100片(600 mg/片)含硫酸伪麻黄碱12 g、GM 16.72 g、HPMC K15M 20.95 g、微晶纤维素9.73 g、硬脂酸镁0.6 g。优化处方所制制剂中氯雷他定15 min的累积溶出度为87.2%,硫酸伪麻黄碱1、6、12 h的累积释放度分别为34.20%、74.32%、94.60%。结论:缓释片芯处方合理、可行,所制备的复方氯雷伪麻缓释片具有缓释作用。     

齐墩果酸缓释片的研制及体外释放度考察

目的：制备齐墩果酸缓释片并考察其体外释放度。方法：以羟丙基甲基纤维素（HPMC）为缓释骨架材料，加淀粉和乳糖作填充剂。通过正交设计优化处方，并考察制剂大小，硬度，释放介质，pH及转速等因素对缓释片体外释放度的影响。结果：正交设计获最优处方为A2B3C1。即亲水凝胶骨架材料为HPMC（K4M），用量为30％。淀粉与乳糖的比例为1：1。药物体外释放行为符合Higuich方程。结论：该方法制得的缓释片具有良好的缓释效果。且制备工艺简单易行。     

格列吡嗪缓释片的制备及工艺研究

目的 制备格列吡嗪缓释片并对释药因素进行考察.方法 采用湿法制粒工艺,以羟丙甲基纤维素(HPMC)为骨架材料,制备格列吡嗪缓释片;运用正交设计法筛选确定制剂处方;对HPMC规格和用量、稀释剂种类等影响释药的因素进行考察,并在此基础上进行处方筛选.结果 格列吡嗪缓释片的体外释药行为符合Higuchi方程,HPMC用量、H...     

酒石酸美托洛尔缓释片工艺研究

目的对酒石酸美托洛尔缓释片的处方工艺进行研究。方法运用正交设计法,通过测定不同时间酒石酸美托洛尔的释放率,来判断其缓释效果从而对缓释骨架材料、填充剂、粘合剂、润滑剂的种类、规格、用量及工艺等进行考察,并对确定的处方及工艺制备的3批样品测定其释放度。结果用HPMC作为骨架材料,微晶纤维素作为填充剂,硬脂酸镁作为润滑剂,3%EC乙醇溶液作为粘合剂制成酒石酸美托洛尔缓释片。结论本制剂工艺简单,所用各种辅料均为国产化,成本低.制得酒石酸美托洛尔缓释片释放度符合规定。     

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.

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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.     

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.