复方骨质增生巴布剂的制备及质量控制

目的:制备复方骨质增生巴布剂并对其质量控制指标进行了研究。方法:以水溶性高分子材料为基质制备复方骨质增生巴布剂,采用高效液相色谱法测定制剂中盐酸利多卡因的含量。按《中华人民共和国药典》中的方法进行了体外释放度的测定,利用改良Franz扩散池研究了巴布剂的透皮吸收行为,并考察了其含膏量、赋形性和黏附性。结果:制备的复方骨质增生巴布剂中盐酸利多卡因的含量稳定,体外释药符合零级动力学方程,释放速率为3.996 mg.cm-2.h-1。其透皮吸收为零级动力学过程,渗透速率为0.073 mg.cm-2.h-1,含膏量、赋形性、黏附性等指标均符合《中华人民共和国药典》标准。结论:复方骨质增生巴布剂为皮肤控释型透皮给药系统。     

盐酸西替利嗪巴布剂的研制及体外释放特性

目的:制备盐酸西替利嗪(CET)巴布剂并研究其体外释药性能和透皮吸收行为.方法:以水溶性高分子材料为基质制备CET巴布剂,采用HPLC法测定制剂中CET的含量.按2000年版中华人民共和国药典方法进行体外释放度的测定,利用Franz扩散池研究巴布剂的透皮吸收行为.结果:CET巴布剂含量稳定,体外释药符合Higuchi方程,释放速率为0.557 7mg·cm-2·h-1/2.透皮吸收符合零级动力学过程,渗透速率为14.58μg·cm-2·h-1.结论:CET巴布剂为皮肤控释型透皮给药系统,为临床治疗过敏性疾病提供了新的给药途径.     

双藤巴布剂中青藤碱、雷公藤甲素的体外释放与体外透皮机制研究

目的:研究双藤巴布剂中青藤碱、雷公藤甲素的体外释放与体外透皮机制;比较以化学单体入药(青藤碱雷公藤甲素巴布剂,STP)与浸膏入药(双藤巴布剂,STEP)释放速率与透皮速率的差异。方法:通过释放度测定法测定体外释放度;通过Franze扩散池法测定药物的体外透皮性,皮肤为裸鼠背部皮肤。结果:STP与STEP中青藤碱、雷公藤甲素的体外释放以Higuchi方程拟合度较优(STP:r青=0.9955,r甲=0.9958;STEP:r青=0.9920,r甲=0.9963)。经皮渗透较好地拟合了零级动力学方程,青藤碱在STP、STEP中的r分别为0.9951与0.9926,透皮速率分别为21.729μg.cm-2.h-1与20.063μg.cm-2.h-1;雷公藤甲素在STP、STEP中的r分别为0.9942与0.9902,透皮速率分别为0.4783μg.cm-2.h-1与0.4168μg.cm-2.h-1。结论:青藤碱、雷公藤甲素在STP、STEP中的释放速率大于其经皮渗透速率,属于皮肤限速型经皮给药制剂。     

盐酸格拉司琼凝胶膏剂的研制及其质量评价

目的:研制盐酸格拉司琼凝胶膏剂并对其质量进行评价。方法:以亲水性高分子材料为基质制备盐酸格拉司琼凝胶膏剂。采用HPLC法测定膏剂中药物含量,以体外渗透实验考察不同pH值对盐酸格拉司琼透皮特性的影响,按《中华人民共和国药典》规定的方法测定其体外释放度、含膏量、赋形性和黏附性。结果:溶液pH值(范围3.25~8.35)显著影响盐酸格拉司琼的体外透皮特性,pH 8.35时的渗透速率最大。凝胶膏剂的药物含量为(0.485±0.020)mg/cm2,含膏量为(81.37±1.02)mg/cm2,体外释放速率为0.996 9 mg.cm-2.h-1/2。结论:制备的盐酸格拉司琼凝胶膏剂符合《中华人民共和国药典》的要求,值得进一步开发。     

咳喘穴位贴片体外透皮速率和体外释放规律研究

目的:研究咳喘穴位贴片体外透皮速率和体外释放规律。方法:采用高效液相色谱法测定透皮接受液和释放液中指标成分盐酸麻黄碱的浓度,计算其渗透速率和体外释药速率。结果:麻黄碱以6.4679μg.cm-2.h-1/2的速率恒速渗透,其体外释药速率为21.382μg.cm-2.h-1/2,其释放过程符合Higuchi方程。结论:咳喘穴位贴片可研制为皮肤限速型的骨架控释系统。     

氨氯地平贴片的体外释药特性

目的研究氨氯地平贴片体外释药特性和离体透皮吸收行为.方法采用HPLC法测定制剂中氨氯地平的含量,按中国药典方法进行体外释放度的测定,利用改良Franz扩散池研究贴片的透皮吸收行为.结果体外释药特性符合Higuchi方程,释放速率为14.59μg·cm-2·h-1.离体透皮吸收行为符合零级动力学过程,渗透速率为12.73μg·cm-2·h-1.结论氨氯地平贴片是皮肤控释型透皮给药系统,为临床治疗高血压提供了新的给药途径.     

黄体酮透皮给药系统体外经皮渗透特性的研究

目的研究黄体酮透皮给药系统的体外经皮渗透特性。方法采用聚丙烯酸酯为骨架制备黄体酮透皮贴片,以离体人皮为透皮模型,采用Valia-Chien扩散池和高效液相色谱法研究促渗剂、药物含量对黄体酮透皮给药系统经皮渗透的影响。结果23%单月桂酸甘油酯与15%棕榈酸乙酯合用对黄体酮促渗效果明显,经皮渗透速率为1.50±0.64μg·cm-2·h-1,增渗倍数达到了21.4倍。贴片中黄体酮含量由0.75mg·cm-2提高到1.0mg·cm-2时,经皮渗透速率明显增大;含量提高到1.25mg·cm-2时,经皮渗透速率无明显变化。结论单月桂酸甘油酯和棕榈酸乙酯联用对黄体酮透皮给药系统体外经皮渗透具有显著的促进作用,黄体酮的最佳含量是1.0mg·cm-2。     

透皮促进剂对散结止痛巴布膏中次乌头碱透皮的影响

目的考察透皮促进剂对散结止痛巴布膏中次乌头碱透皮吸收的影响。方法建立皮肤渗透液中次乌头碱含量测定的HPLC方法。利用大鼠腹部皮肤和Franz垂直扩散池进行体外透皮扩散试验,比较不同浓度的氮酮和桉叶油对散结止痛巴布膏中次乌头碱透皮速率的影响。结果不加透皮促进剂的散结止痛巴布膏中次乌头碱的透皮速率为0．65mg·cm^-2·h^-1;2％氮酮与10％丙二醇组成的复合透皮促进剂使次乌头碱透皮速率增加9．87倍;2％桉叶油增加次乌头碱透皮速率12．23倍。结论散结止痛巴布膏的透皮促进剂可采用2％桉叶油或2％氮酮与10％丙二醇合用。     

来氟米特贴片的制备及体外释药特性

目的制备来氟米特贴片,研究其体外释药特性和离体透皮吸收行为。方法以聚异丁烯为压敏胶制备来氟米特贴片,采用HPLC法测定制剂中来氟米特的含量,按《中华人民共和国药典》(2000年版)方法进行体外释放度的测定,利用改良Franz扩散池研究贴片的透皮吸收行为。结果该药体外释药特性符合Higuchi方程,释放速率为64.57μg·cm-2·h-1/2。离体透皮吸收行为符合零级动力学过程,渗透速率为5.99μg·cm-2·h-1。结论来氟米特贴片是皮肤控释型透皮给药制剂,为临床治疗类风湿性关节炎提供了新的给药途径。     

不同促渗剂对盐酸利多卡因巴布剂透皮的影响

目的：研究促渗剂对盐酸利多卡因巴布剂透皮作用的影响。方法：用紫外分光光度法检测浓度，采用Franz扩散池，用离体小鼠皮肤进行体外透皮扩散试验，计算含不同促渗剂的5％盐酸利多卡因巴布剂的累积渗透量Q及渗透速率是。结果：不同促渗剂对5％盐酸利多卡因巴布剂的累积渗透量Q及渗透速率是的影响大小为：丙二醇〉薄荷脑〉尿素。但只有丙二醇表现出显著性（P〈0．05），尿素和薄荷脑对盐酸利多卡因巴布剂透皮作用基本无影响。5％的丙二醇对其影响最大。结论：提示5％的丙二醇可作为促渗剂在盐酸利多卡因巴布剂中使用。     

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.