盐酸克林霉素胶囊溶出度测定方法研究

目的：建立紫外分光光度法测定盐酸克林霉素胶囊溶出度的方法。方法：以0．1mol／L的盐酸作为溶出介质,转速为100r·min-1,紫外分光光度法测定溶出量,检测波长为201nm。结果：在12．1—72．7μg/ml内呈良好的线性关系,r=0．9990,精密度RSD为0．12％（n=6）。结论：本方法简单快速,准确稳定,可用于盐酸克林霉素胶囊溶出度。     

盐酸克林霉素棕榈酸酯分散片和干混悬剂溶出度HPLC测定法的建立

目的 研究盐酸克林霉素棕榈酸酯分散片和干混悬剂的溶出介质,建立了高效液相色谱法测定盐酸克林霉素棕榈酸酯分散片和干混悬剂的溶出度.方法 以0.4％十二烷基硫酸钠溶液为溶出介质,桨法,转速为75r/min,分散片和干混悬剂分别在20min和15min时取样,取样后采用HPLC法测定.结果 盐酸克林霉素棕榈酸酯在15～115μg/mL的范围内呈良好的线性关系(r=0.9999),盐酸克林霉素棕榈酸酯分散片的平均回收率为99.1％(RSD=0.9％,n=9),盐酸克林霉素棕榈酸酯干混悬剂的平均回收率为103.1％(RSD=2.9％,n=9),溶出液稳定,分散片2批在20min时和干混悬剂3批在15 min时平均溶出度均在75％以上并且有较好的均一性.结论 该方法快速、简便,结果准确可靠,重现性好.     

高效液相色谱法测定克林霉素磷酸酯片的溶出度

目的:用高效液相色谱法测定克林霉素磷酸酯片的溶出度.方法:采用转篮法测定克林霉素磷酸酯片的溶出度,以高效液相色谱法测定其浓度.色谱柱为RP-C18柱(5μm,200 mm×4.6 mm),流动相为0.1 mol/L磷酸二氢钾溶液-乙腈(775:225),流速为1.0 mL/min,检测波长为210 nm,室温下测定.结果:在0.04～1.00 mg/mL的浓度范围内,线性关系良好(r=0.999 2),平均回收率为100.0%,RSD为0.88%.结论:高效液相色谱法分析速度快,结果准确,适用于克林霉素磷酸酯片溶出度的测定.     

紫外分光光度法测定盐酸法倔唑片的溶出度

目的:建立测定盐酸法倔唑片溶出度的方法。方法:采用紫外分光光度法,以水为溶媒,在280nm波长处测定其吸收度,并计算溶出度。结果:盐酸法倔唑的线性范围为1～10μg.mL-1(r=0.9999),平均回收率为99.38%(RSD=0.33%);3批样品的30min溶出度均在90%以上。结论:本方法简便、准确,结果可靠,可用于该制剂的溶出度测定。     

盐酸克林霉素胶囊的溶出度研究

目的建立盐酸克林霉素胶囊的溶出度测定方法。方法以磷酸二氢铵溶液(取磷酸二氢铵2.88g,加水溶解并稀释成1000mL,用80%磷酸溶液调节pH值至3.0)为溶出介质,检测波长为214nm,以磷酸二氢铵溶液(取磷酸二氢铵2.88g,加水溶解并稀释成1000mL,用80%磷酸溶液调节pH值至3.0)-甲醇(210∶300)为流动相,流速0.7mL/min。结果盐酸克林霉素0.332~6.640μg的范围内,线性关系良好,Y=-3844+3.542e+004X,r=0.9962(n=6)。结论方法快速准确,可作为盐酸克林霉素胶囊的质量控制方法。     

地巴唑片溶出度测定方法的研究

目的:建立地巴唑片溶出度测定方法.方法:以0.1mol/L盐酸溶液为溶出介质,采用紫外分光光度法测定.结果:该方法线性关系良好(r=0.9997),平均回收率为99.82%(RSD=0.51%).结论:本方法适用于地巴唑片的溶出度测定.     

盐酸溴己新片溶出度测定方法研究

目的:建立紫外分光光度法测定盐酸溴己新片溶出度的方法。方法:以水为溶出介质,转速为75r·min-1,紫外分光光度法测定溶出量,检测波长为245nm。结果:在4~32μg·ml-1浓度范围内呈良好的线性关系,r=0.9998,精密度RSD为0.29%(n=6)。结论:本方法简便、准确,可用于盐酸溴己新片溶出度的测定。     

盐酸沙格雷酯片的溶出度研究

目的:建立测定盐酸沙格雷酯片溶出度的方法。方法:采用紫外分光光度法,以0.1mol.L-1盐酸为溶媒,转速为100r.min-1,取样时间为30min ,在273nm波长处测定其溶出度。结果:盐酸沙格雷酯检测浓度的线性范围为3～30μg·mL-1(r=0.999 7) ;平均回收率为100%～100.35%,RSD=0.73%,3批样品30min溶出度均在90%以上。结论:本方法简便、准确、可靠,可用于该制剂的溶出度测定。     

盐酸贝尼地平片溶出度的测定

目的:建立盐酸贝尼地平片溶出度的测定方法。方法:根据《中国药典》2005年版溶出度测定方法第三法(小杯法),以0.1mo·lL~(-1)盐酸为介质,转速为50r·min~(-1),于30min时取样,采用紫外分光光度法在359nm波长处测定吸光度,并计算累积溶出度。结果:盐酸贝尼地平检测浓度线性范围为5～30μg·mL~(-1)(r=0.9999);平均回收率为99.76%,RSD=0.47%;3批样品30min时累积溶出度均在80%以上。结论:所建立的溶出度方法简单、可靠,可用于盐酸贝尼地平片溶出度的测定。     

盐酸雷尼替丁胶囊溶出度试验方法探讨

目的:测定盐酸雷尼替丁胶囊的溶出度以控制产品质量.方法:照 2000年版<中国药典(二部)>溶出度测定法中第一法(转篮法),以水为溶剂,转速为 100 r/min,45 min时采样;用紫外分光光度法测定盐酸雷尼替丁胶囊的溶出度.结果:盐酸雷尼替丁线性范围为 6～ 20 μ g/mL(r=0.999 9),回收率为 99.7% (RSD=0.9% ,n=5).结论:所用方法准确、可靠、简便、易行,可作为制剂的溶出度测定方法.     

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.