HPLC测定硬脂酸红霉素颗粒中的红霉素A

目的 采用HPLC法测定硬脂酸红霉素颗粒中红霉素A的含量.方法 采用资生堂C18MG色谱柱(250 mm× 4.6mm,5μm),流动相为乙腈-磷酸盐缓冲液(60∶40),流速1.0 mL·min-1,检测波长215 nm.结果 0.039 ～ 1.94 mg· mL-1红霉素A与峰面积的线性关系良好(r ＝0.9998),平均回收率为100.7％ (n ＝9).结论 所用方法灵敏、准确、简便.     

HPLC法测定琥乙红霉素静脉乳剂的含量

目的:建立琥乙红霉素静脉乳剂的含量测定方法.方法:采用Agilent Zorbax SB-C18柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.02 mol·L-1醋酸铵缓冲盐溶液(65∶ 35),检测波长215 nm,流速为1.0ml·min-1,柱温25℃,进样量20μl.结果:琥乙红霉素在60 ～ 600 μg·ml-1的浓度范围内与峰面积呈良好的线性关系(r =0.999 1),平均回收率为97.92％,RSD为0.43％(n=9).结论:该方法简便、快速、准确,可用于琥乙红霉素的含量测定及稳定性分析.     

琥乙红霉素片含量测定方法的改进

目的:改进琥乙红霉素片剂含量的测定方法.方法:采用高效液相色谱法,以Waters XBridgeTM Shied C18(250 mm×4.6 mm,5 μm)为色谱柱;0.067 mol·L-1磷酸二氢铵溶液(用三乙胺调节pH至6.5)-乙睛(65:35)为流动相;检测波长210 nm;流速为1.0 ml·min-1;柱温为20℃.结果:红霉素A在39.83～139.41 μg·ml-1范围内呈良好的线性关系(r=0.999 3),平均回收率为98.6%(RSD=0.9%,n=9),检测限为1.19 μg,定量限为3.58 μg.将该法测定结果与效价法测定的含量进行比较,结果基本一致.结论:该方法更简便、准确,重复性好.     

HPLC测定复方红霉素洗剂中红霉素的含量

目的建立复方红霉素洗剂中红霉素的含量测定方法.方法采用高效液相色谱法,色谱柱为Hypersil ODS C18柱(4.6 mm×250 mm,5 μm),流动相为0.1 mol/L磷酸二氢铵缓冲液(三乙胺调pH 6.5)-乙腈(65:35),流速为1.0 ml/min,检测波长为210 nm.结果红霉素在0.55～2.75 mg/ml浓度范围内,峰面积与其浓度呈良好的线性关系,r=0.9992(n=5),平均回收率为99.3%,RSD为1.26%(n=6).结论本法简便、准确、灵敏度高、重复性好,可作为复方红霉素洗剂中红霉素含量的测定方法.     

HPLC法测定琥乙红霉素口服制剂中红霉素残留量

目的建立琥乙红霉素口服制剂中红霉素残留量的检测方法.方法采用HamilT＆NRP-1 L21(250mm×4.6mm)色譜柱,柱温60℃,磷酸盐缓冲液(0.067mol·L-1,pH9.0)-乙晴-叔丁醇-水(4535128)为流动相,流速0.8ml·min-1,检测波长215nm,进样量100μL.结果红霉素在300u·ml-1～3000u·ml-1范围内呈良好线性关系(r=0.9995),平均回收率为103.7%,RSD为1.1%,最低检测限为15u.结论该法专属性强,灵敏度高,重现性较好,可作为琥乙红霉素口服制剂中红霉素残留量的测定方法.     

高效液相色谱法测定红霉素肠溶胶囊的含量

目的 建立测定红霉素肠溶胶囊含量的高效液相色谱法.方法 色谱柱为Diamonsil C18柱(250 mm×4.6 mm,5 μm),流动相为0.067 mol/L磷酸二氢铵溶液(用三乙胺调pH至6.5)-乙腈(58∶42),检测波长为210 nm,流速为1.0 mL/min,柱温为30℃.结果 质量浓度线性范围为20～ 140 g/L(r=0.999 9),平均加样回收率为100.14％,RSD为0.29％(n=6).结论 所用方法简便、准确、灵敏度高、重现性好,可用于红霉素肠溶胶囊的含量测定.     

HPLC测定复方红霉素洗剂中红霉素的含量

目的建立复方红霉素洗剂中红霉素的含量测定方法。方法采用高效液相色谱法,色谱柱为Hypersil ODS C18柱(4.6mm×250mm,5μm),流动相为0.1mol/L磷酸二氢铵缓冲液(三乙胺调pH6.5)-乙腈(65∶35),流速为1.0ml/min,检测波长为210nm。结果红霉素在0.55~2.75mg/ml浓度范围内,峰面积与其浓度呈良好的线性关系,r=0.9992(n=5),平均回收率为99.3%,RSD为1.26%(n=6)。结论本法简便、准确、灵敏度高、重复性好,可作为复方红霉素洗剂中红霉素含量的测定方法。     

HPLC测定环酯红霉素中的3种杂质

目的采用HPLC法测定环酯红霉素中的3种杂质。方法色谱柱为Kromasil Eternity-5-C18柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.025 mol·L-1磷酸氢二铵溶液(磷酸先调p H6.2,再用三乙胺调p H7)(50∶50),柱温7℃,流速1.0m L·min-1,检测波长210 nm。结果环酯红霉素中3种杂质的分离较好,与主峰均能有效分离,线性范围为0.01~0.2 mg·m L-1(r=0.9999);3种杂质的平均回收率分别为89.2%、99.1%、97.1%,RSD分别为2.62%、2.81%、0.82%。结论所用方法简便、准确、重复性好,可用于环酯红霉素的质量控制。     

琥乙红霉素效价测定中最佳水解条件的选择

目的:选取琥乙红霉素效价测定中的最佳水解条件。方法:在受控的不同温度条件下,用高效液相色谱法测定不同时间琥乙红霉素溶液的水解程度和红霉素溶液的稳定性。其色谱柱为HYPERSIL BDS C_(18)柱(5μm,4.6 mm×200 mm),柱温50℃,流动相为叔丁醇-PBS(pH 7.0)[取0.2 mol·L~(-1)的磷酸氢二钾溶液50 mL,加入0.2 mol·L~(-1)的氢氧化钠溶液29.63mL,水 200 mL,用磷酸调pH至7.01]-水-乙腈(1:60:12:12),流速1.0 mL·min~(-1),UV检测波长 215 nm,进样量 100 μL。结果:琥乙红霉素的水解反应为一级反应,且水解反应速率与温度之间的关系,符合阿仑尼乌斯经验公式。在20℃的条件,琥乙红霉素至少应放置16 h方可完全水解。在40℃条件,琥乙红霉素至少应放置6 h使完全水解;在此条件下红霉素未发生分解。结论:选择40℃为琥乙红霉素效价测定的水解温度,可以大大加快实验速度。     

高效液相色谱法测定肤痒颗粒中红花黄色素A的含量

目的:建立肤痒颗粒中红花黄色素A含量测定的高效液相色谱法.方法:采用wfliers C<,18>色谱柱(200 mm×4.6mm,5μm),以甲醇-乙腈-0.05%磷酸溶液(20:2:78)为流动相,流速为1.0mL·mjn-1.用二极管阵列检测器检测,检测波长403 nm,柱温36℃.结果:方法的线性范围为3.698～36.98 mg·L-1(r=0.999 6),精密度RSD为0.38%(n=7),重复性RSD为0.67%(n=7),红花黄色素A的平均回收率为99.57%,RSD为0.91%(n=9).结论:本方法操作简便,结果准确、可靠,可用于肤痒颗粒中红花黄色素A的含量测定.     

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.     

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.