蒙脱石散对盐酸左氧氟沙星体外吸附的影响

目的: 探讨蒙脱石散对盐酸左氧氟沙星体外吸附的影响.方法: 采用不同剂量的盐酸左氧氟沙星分别与3 g蒙脱石散混合,加入0.1 mol·L-1盐酸溶液中,在(37±0.5)℃水浴中恒温2 h后过滤,用紫外分光光度法测定盐酸左氧氟沙星的含量变化.结果: 蒙脱石散对盐酸左氧氟沙星的吸附率为(98.37±0.03)%.结论: 蒙脱石散对盐酸左氧氟沙星有极强吸附,因此应避免两种药物同时服用.     

紫外分光光度法测定左氧氟沙星滴耳液中左氧氟沙星的含量

目的建立左氧氟沙星滴耳液中左氧氟沙星的含量测定。方法紫外分光光度法。溶剂为0.1 mol.L-1盐酸溶液,检测波长293 nm。结果左氧氟沙星在2~8 mg.L-1范围内,线性关系良好,r=0.9995。回收率为99.6%。结论该法可准确测定左氧氟沙星滴耳液中左氧氟沙星的含量,适用于制剂的质量控制。     

高效液相色谱法测定左氧氟沙星滴鼻液中左氧氟沙星的含量

目的 建立高效液相色谱法测定左氧氟沙星滴鼻液中左氧氟沙星的含量.方法 采用美国Waters高效液相色谱仪,流动相为枸橼酸(0.05 mol·L-1枸橼酸溶液用三乙胺调节Ph值至4.0)-乙腈(79∶ 21),流速1.0 ml·min-1,检测波长293 nm.结果 左氧氟沙星在50～500 mg·L-1范围内,线性关系良好,r=0.9995.回收率为99.2%.结论 本法可准确测定左氧氟沙星滴鼻液中左氧氟沙星的含量,适用于产品的质量控制.     

盐酸左氧氟沙星胶囊含量测定方法的改进

目的改进盐酸左氧氟沙星胶囊含量测定方法。方法与结果采用左氧氟沙星对照品,以0.1mol·L-1盐酸溶液为溶剂,在293nm波长处分别测定吸收度,从而进行含量测定。本法线性关系良好,平均回收率为99.72%,RSD为0.33%。结论本法简单准确,结果可靠。     

盐酸左氧氟沙星液状眼用凝胶的制备及质量控制

目的:建立盐酸左氧氟沙星液状眼用凝胶的制备及质量控制方法.方法:以卡波姆为增粘剂,制备盐酸左氧氟沙星液状眼用凝胶,以XTerra RP18色谱柱为分离柱,以0.1%磷酸:乙腈(87:13)为流动相,采用HPLC法测定.结果:左氧氟沙星浓度在10.2～51.2 μg·ml-1范围内线性关系良好,r=0.999 9.左氧氟沙星的平均回收率为99.60%,RSD=0.61%.结论:此法操作简单、结果准确,可用于盐酸左氧氟沙星液状眼用凝胶的质量控制.     

二元线性回归-双波长分光光度法测定左氧氟沙星替硝唑注射液的含量

目的建立测定左氧氟沙星替硝唑注射液含量的二元线性回归-双波长分光光度法。方法以0.001mol.L-1盐酸溶液为溶剂,分别在293和317.5 nm波长处测定左氧氟沙星替硝唑复方溶液的吸光度。应用二元线性回归方法,求左氧氟沙星、替硝唑浓度与吸光度的线性方程,计算左氧氟沙星与替硝唑的含量。结果左氧氟沙星浓度在2.294~11.470μg.mL-1、替硝唑浓度在3.348~16.740μg.mL-1,浓度与吸光度呈良好的线性关系,相关系数R1(λ293 nm)=0.999 96,R2(λ317.5 nm)=0.999 96。左氧氟沙星平均回收率为100.8%,RSD=0.67%;替硝唑平均回收率为99.40%,RSD=0.65%。结论该方法准确可行,简便快捷,重复性较好。     

盐酸左氧氟沙星片微生物限度检查法的方法学研究

目的:建立盐酸左氧氟沙星片的微生物限度检查方法。方法:采用平皿法、薄膜过滤法和薄膜过滤法加中和剂(硫酸镁)对盐酸左氧氟沙星片进行微生物限度检查法研究。结果:细菌检查采用含0.1 mol/L硫酸镁的pH 7.0无菌氯化钠-蛋白胨缓冲液(稀释液)500 ml分5次冲洗的薄膜过滤法(培养基中再加入1 mol/L硫酸镁溶液1 ml),可以有效消除抑菌成分对试验的影响,霉菌和酵母菌检查采用平皿法,5种阳性菌的回收率均可达到70%;控制菌采用含0.1 mol/L硫酸镁的稀释液300 ml冲洗的薄膜过滤法进行验证后结果符合要求。结论:建立的盐酸左氧氟沙星片微生物限度检查方法操作简单、可行,结果可靠。     

盐酸左氧氟沙星软胶囊、硬胶囊和片剂的人体药动学研究

目的:使用HPLC法测定人血浆中左氧氟沙星的浓度,并研究盐酸左氧氟沙星软胶囊、硬胶囊和片剂在健康人体内的药代动力学。方法:20名健康男性志愿者单剂量口服200mg盐酸左氧氟沙星后,采集不同时间点血样测定血药浓度。结果:左氧氟沙星线性范围为0.041～5.180mg/L,日内和日间精密度(RSD)均小于5.0%。盐酸左氧氟沙星软胶囊主要药动学参数:tmax:(0.8±0.3)h;Cmax:(2.8±0.9)mg/L;AUC0-30:(14.7±1.8)mg·L-1.h;AUC0-∞:(15.4±1.9)mg·L-1.h;t1/2:(6.9±0.4)h。结论:盐酸左氧氟沙星软胶囊的药动学参数与硬胶囊和片剂的差异无统计学意义。     

差示分光光度法测定呋塞米片的含量

目的探讨呋塞米片含量测定的方法。方法在波长280 nm处,呋塞米以其在0.1 mol.L-1氢氧化钠溶液为参比液,测得其在0.1 mol.L-1盐酸溶液中的差示吸收值。结果呋塞米浓度在5.10～40.84 mg·L-1范围内ΔA与溶液浓度呈良好线性关系(r=0.999 9),平均回收率为99.69%(n=6),RSD为0.95%。结论该方法简便、快速、准确,可用于呋塞米片的质量控制。     

高效液相色谱法测定注射用甲磺酸左氧氟沙星的含量

目的建立高效液相色谱法测定注射用甲磺酸左氧氟沙星的含量。方法采用ODS2色谱柱(5μm,4.6mm×200mm),乙腈-0.05mol.L-1磷酸二氢钾溶液(pH2.2)-0.05mol.L-1四丁基溴化铵溶液(116∶861∶23)为流动相,流速1mL.min-1,检测波长293nm,外标法计算含量。结果甲磺酸左氧氟沙星在20μg.mL-1~200μg.mL-1的浓度范围内,线性关系良好,回归方程Y=55667.78X 10.32886,r=0.99998;系统精密度RSD为0.1%(n=6)。结论本方法操作简便、快捷,方法的精密度、准确度均能很好地满足质量控制的要求,适合于注射用甲磺酸左氧氟沙星的含量测定。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.