HPLC法测定注射用阿奇霉素磷酸二氢钠的含量及有关物质

目的建立一种高效液相色谱方法来测定注射用阿奇霉素磷酸二氢钠含量及有关物质。方法以Shiseido C18(4.6 mm×250 mm,5μm)色谱柱为分析柱,以磷酸盐缓冲液(0.05 mol·L-1磷酸氢二钾溶液,用20%磷酸溶液调节pH值至8.2)-乙腈(40∶60)为流动相,柱温30℃,检测波长为210 nm,流速为1.0 mL·mim-1。结果阿奇霉素在10⁵ 000μg·mL-1范围内浓度与峰面积呈良好线性关系,r=1.000 0,平均回收率为100.6%,RSD为0.99%(n=9)。结论本方法可快速、准确的测定注射用阿奇霉素磷酸二氢钠含量及有关物质的测定。     

高效液相色谱法测定阿奇霉素在其分散片中的含量

目的建立HPLC法测定阿奇霉素在其分散片中的含量.方法采用phenomenex C18柱(150 mm×4.60 mm,5μm );流动相为0.02 mol·L-1磷酸氢二钾溶液-乙腈(30:70 );检测波长为210 nm.结果阿奇霉素在1.0～3.0 mg·mL-1浓度与峰面积呈良好的线性关系(r=0.999 96),平均回收率为100.01%,RSD为0.63%.结论方法简便、快速、灵敏、准确.     

HPLC法测定注射用阿奇霉素的含量

目的:建立了HPLC法测定注射用阿奇霉素的含量.方法:采用ODS柱,以0.06mol/L磷酸氢二钾溶液(10mol/ml氢氧化钾溶液调节pH至9.0)-乙腈(35:65)为流动相,柱温:40℃;流速为1.0ml/min,检测波长为215nm.结果:阿奇霉素的线性范围为10～50μg/ml,平均回收率为99.7%(RSD=0.28%).结论:本方法准确、快速、简便.     

高效液相色谱法测定阿奇霉素片中阿奇霉素含量

目的:建立阿奇霉素片含量测定的HPLC法。方法:采用Thermo C18(250 mm×4.6 mm,5μm)色谱柱,流动相为磷酸盐缓冲液(取0.05 mol/L磷酸氢二钾溶液,用20%的磷酸溶液调节pH至8.2)-乙腈(45∶55)为流动相,检测波长为210 nm。结果:阿奇霉素在0～1.4 mg/ml范围内线性关系良好,平均回收率99.6%,RSD为0.56。结论:本方法准确可靠,灵敏度高,重现性好,可用于阿奇霉素片含量测定。     

HPLC法同时测定阿奇霉素滴眼液中阿奇霉素及苯扎氯铵的含量

目的建立一种高效液相色谱法同时测定阿奇霉素滴眼液中阿奇霉素及苯扎氯铵的含量。方法采用十八烷基硅烷键合硅胶色谱柱(4.6 mm×150 mm,5μm),柱温30℃,以乙腈-磷酸盐缓冲液(取0.05 mol.L-1磷酸氢二钾溶液,用20%磷酸调节pH至8.2)(58∶42)为流动相;检测波长210 nm;流速:1.0 mL.min-1。结果阿奇霉素在1.002 8～5.014 0 mg.mL-1的浓度范围内,苯扎氯铵在6.15μg.mL-1～14.35μg.mL-1的浓度范围内均呈线性。阿奇霉素的平均回收率100.68%,RSD为0.50%(n=9);苯扎氯铵的平均回收率100.59%,RSD为0.92%(n=9)。阿奇霉素与苯扎氯铵的定量限分别为750 ng.mL-1、46 ng.mL-1,平均含量分别为106.94%及100.04%,RSD分别为0.94%及0.67%。仪器重复性RSD值均在2.0%以下。结论本方法简单、准确,可同时测定样品中阿奇霉素及苯扎氯铵的含量。     

阿奇霉素滴眼液有关物质检查方法的研究

目的建立高效液相色谱法测定阿奇霉素有关物质的方法。方法采用硅胶表面经杂化处理的十八烷基硅烷键合硅胶色谱柱Capcell pak MGⅡ(4.6 mm×150 mm,5μm),柱温30℃,以乙腈-磷酸盐缓冲液(0.05 mol.L-1磷酸氢二钾溶液,用20%磷酸调节pH至8.2)(58∶42)为流动相,流速为1.0 mL.min-1,检测波长为210nm。结果阿奇霉素的检测限及定量限分别为300、750 ng.mL-1;阿奇霉素与杂质峰及各杂质峰之间能够有效分离;阿奇霉素在60.2～180.6μg.mL-1范围内线性良好;供试品溶液在8 h内稳定性良好。结论本方法科学、简单、准确,适用于阿奇霉素滴眼液的有关物质检查。     

HPLC法测定阿奇霉素胶囊的含量

目的建立阿奇霉素胶囊含量的HPLC法。方法采用Shim-pack VP-ODS(4.6 mm×150 mm,5 nm)(岛津柱),流动相为0.067 mol.L-1磷酸二氢铵溶液(三乙胺调pH至6.5)-乙腈(74∶26),检测波长200 nm,流速1 ml.min-1,柱温30℃。结果阿奇霉素在0.76~3.82 g.L-1范围内线性关系良好,r=0.999 9,方法的回收率为100.2%(n=3)。结论本法简便、准确、重现性好,结果可靠,可用于阿奇霉素的含量测定。     

HPLC法分析注射用乳糖酸阿奇霉素的有关物质和含量

目的:建立一种能用于注射用乳糖酸阿奇霉素中有关物质和含量控制的HPLC方法。方法:采用CAPCELL PAK C18(MGⅡ)柱(150 mm×4.6 mm,5μm),柱温30℃,流动相为磷酸盐缓冲液(0.05 mol.L-1磷酸氢二钾溶液,磷酸调pH至8.4±0.1)-乙腈(45∶55),流速1.0 ml.min-1,检测波长210 nm。结果:有关物质与主成分阿奇霉素能达到基线分离;酸根对有关物质的测定无影响;阿奇霉素在0.469 0～1.407 0 mg.ml-1范围内线性关系良好(r=0.999 5),平均回收率98.6%(n=6),RSD为0.4%。结论:该法简便,准确,其他组分不干扰测定,可用于本品的质量控制。     

HPLC法测定阿奇霉素及阿奇霉素胶囊的含量

目的：建立HPLC法测定阿奇霉素及阿奇霉素胶囊的含量。方法：色谱柱为资生堂C18MGⅡ柱（250mm×4．6mm,5μm）,乙腈-磷酸盐缓冲液（取磷酸氢二钾8．7g,加水溶解稀释成1000ml,用磷酸调pH至8．2）（60：40）为流动相,流速为1．0ml·min^-1,检测波长210nm。结果：阿奇霉素在17．5～875．0μg·ml^-1的范围内,线性关系良好（r=0．9999）。平均回收率为99．7％,RSD=0．47％（n=9）。结论：本法灵敏、准确、简便。     

不同产地罂粟壳、罂粟籽中吗啡含量的测定

目的 采用HPLC法测定不同产地罂粟壳、罂粟籽中吗啡的含量,为今后罂粟壳药材、饮片及制剂标准的提高提供依据.方法 使用DikMa-C8(250 mm×4.6 mm,5μm)色谱柱,乙腈-0.01 mol·L-1磷酸氢二钾溶液-0.005 mol·L-1庚烷磺酸钠溶液(20:40:40)为流动相,流速为1.0 mL·mi...     

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.

     

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.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.