联立方程组新解法测定氯霉素地塞米松滴眼液中两组分的含量

建立氯霉素地塞米松滴眼液中两组分的含量测定方法。采用联立方程组新解法直接测定氯霉素地塞米松滴眼液中氯霉素和地塞米松磷酸钠的含量。以水为空白,分别以278nm和242nm为测定波长。氯霉素和地塞米松磷酸钠的平均回收率及RSD分别为100.2％、0.72％;99.43％、1.26％。氯霉素地塞米松滴眼液中两组分的含量,可采用联立方程组新解法,不经分离直接测定其吸收值,方法简便、快速、重复性好,可推广应用。     

系数倍率法测定地塞米松滴眼液的含量

目的:探讨地塞米松滴眼液含量测定的方法。方法:采用系数倍率法,不经分离,直接测定地塞米松滴眼液中地塞米松的含量。测定波长为242nm和254nm。结果:地塞米松平均回收率为99.53％,CV为0.44％(n=6)。结论:用系数倍率法,不经分离,直接测定地塞米松的含量,结果满意。     

联立方程组新解法测定氯霉素地塞米松滴眼液中两组分的含量

建立氯霉素地塞米松滴眼液中两组分的含量测定方法。采用联立方程组新解法直接测定氯霉素地塞米松滴眼液中氯霉素和地塞米松磷酸钠的含量。以水为空白,分别以278nm和242nm为测定波长。氯霉素和地塞米松磷酸钠的平均回收率及RSD分别为100．2％、0．72％;99．43％、1,26％。氯霉素地塞米松滴眼液中两组分的含量,可采用联立方程组新解法,不经分离直接测定其吸收值,方法简便、快速、重复性好,可推广应用。     

HPLC法测定醋酸地塞米松片含量

目的:建立高效液相电谱法测定醋酸地塞米松片含量并分离掺假物质。方法:采用ODS柱,流动相为甲醇:水(70:30),检测波长240nm。结果:醋酸地塞米松在25.76～64.40μg·ml~(-1)(r=1.0000,n=7)浓度呈线性关系,平均回收率为99.83％,RSD=0.27％。结论:本方法操作简便、快速、准确,能很好地定量测定醋酸地塞米松片含量并分离掺入的醋酸泼尼松或泼尼松。     

应用联立方程组新解法测定两种复方制剂中两组分的含量

目的：测定氯霉素地塞米松滴眼液及复方诺氟沙星涂剂中两组分的含量。方法：采用联立方程组新解法，不经分离直接测定氯霉素地塞米松滴眼液及复方诺氟沙星涂剂中的氯霉素、地塞米松磷酸钠、诺氟沙星的含量。结果：以278、242nm分别为氯霉素地塞米松滴眼液中两组分的测定波长，以蒸馏水为空白，氯霉素和地塞米松磷酸钠的平均回收率及RSD分别为100．26％，0．15％和99．96％，0.38％；以273、242nm为诺氟沙星涂剂中两组分的测定波长，以蒸馏水为空白，诺氟沙星和地塞米松磷酸钠的平均回收率及RSD分别为100．56％，0．56％和99．93％，0．31％。结论：本法操作简便快速，重现性好，可消除各处方中两组分的相互干扰，结果满意。     

双波长分光光度法测定复方氧氟沙星滴耳液

应用双波长分光光度法,在240nm、272.9nm和294nm波长处,测定复方氧氟沙星滴耳液中醋酸地塞米松和氧氟沙星的含量,平均回收率分别为101.9％和99.50％,RSD分别为0.8976和0.8714。该方法快速简便,结果准确。     

系数倍率法测定氯地滴眼液中氯霉素及磷酸地塞米松的含量

目的:探讨氯地滴眼液中氯霉素和磷酸地塞米松的含量测定方法。方法:采用系数倍率法,于244和279nm波长处分别测定氯霉素和磷酸地霉米松的吸收度,求出K值。绘制氯霉素与磷酸地塞米松混合液的标准曲线,得出△A与浓度的关系方程。测定样品在244和279nm波长处的吸收度,代入△A与浓度的关系方程,即可求出样品中氯霉素和磷酸地塞米松的含量。结果:氯霉素和磷酸地塞米松的平均回收率为99.6％,RSD分别为0.31％和0.34％。结论:此方法用于氯地滴眼液的含量测定,可避免氯霉素和磷酸地塞米松的相互干扰,方法简单,结果准确。     

复方醋酸地塞米松搽剂的含量测定

目的:建立复方醋酸地塞米松搽剂中樟脑和醋酸地塞米松的含量测定方法。方法:采用一阶导数光谱法于(305±1)nm波长处直接测定樟脑的含量;采用可见分光光度法于(485±1)nm波长处测定醋酸地塞米松的含量。结果:樟脑含量在1.62-3.22mg/mL浓度范围内,线性关系良好,相关系数r=0.999 4,平均回收率99.89%,RSD为0.34%。醋酸地塞米松含量在122.04-227.81μg/mL浓度范围内,线性关系良好, 相关系数r=0.999 7,平均回收率99.18%,RSD为1.32%。结论:本方法简便、快速、准确,可用于复方醋酸地塞米松搽剂的质量控制。     

高效液相色谱法测定醋酸地塞米松软膏的含量

目的:研究快速、简便地测定醋酸地塞米松软膏中醋酸地塞米松含量的方法。方法:采用高效液相色谱法,以甲睾酮为内标,测定醋酸地塞米松的含量。结果:醋酸地塞米松浓度在25～75μg/ml范围内呈良好的线性关系。分别以醋酸地塞米松和甲睾酮的浓度比与面积比为纵坐标和横坐标作标准曲线,得回归方程:Y=-0.03999 1.47918X,r=0.9966,平均回收率为99.33％(n=5)。结论:与分光光度法比较,用高效液相色谱法测定醋酸地塞米松软膏的含量,操作简便,结果准确。     

复方硫酸庆大霉素滴鼻剂的制备与质量控制

目的 :不经分离直接测定制剂中硫酸庆大霉素、盐酸麻黄碱、地塞米松磷酸钠3组分含量。方法 :利用Hantzsh反应使庆大霉素形成二氢砒啶衍生物 ,在紫外330nm波长处测定其含量 ;应用双波长原理 ,分别在紫外测定波长256.5nm、241.6nm ,参比波长228.4nm、266.4nm处测定盐酸麻黄碱、磷酸地塞米松含量。结果 :硫酸庆大霉素、盐酸麻黄碱、地塞米松磷酸钠3组分平均回收率分别为 (100.74±0.2) %、(100.15±0.66) %、(99.46±0.35) % ,n=5。结论 :方法简便、快速、准确、稳定 ,适用于该制剂的快速质量控制。     

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.