高效凝胶色谱法测定注射用盐酸头孢甲肟中的高分子杂质

目的 建立高效凝胶色谱法测定注射用盐酸头孢甲肟中的高分子杂质. 方法采用高效凝胶色谱法,色谱柱为高效凝胶Tsk gel G2000 SWxl(300 mm×7.8 mm,5 μm),流动相为pH7.0的0.005 mol•L^-1磷酸盐缓冲液[0.005 mol•L^-1磷酸氢二钠溶液 0.005 mol•L^-1磷酸二氢钠溶液(61:39)]-乙腈(95:5);流速:0.8 mL•min^-1;检测波长为234 nm,进样量为20 μL. 结果 供试品溶液在0.067～2.700 mg•mL^-1浓度范围内,溶液的浓度与高分子杂质的峰面积总和呈良好的线性关系(r＝0.998 8);盐酸头孢甲肟在0.001～0.010 mg•mL^-1浓度范围内,与峰面积呈良好的线性关系(r＝0.999 9). 结论 该测定方法简便,重复性好,可靠性高,可用于注射用盐酸头孢甲肟中高分子杂质的质量控制.     

羧甲基壳聚糖阴道温敏性原位凝胶的研制及体外质量考察

摘要：目的:优化羧甲基壳聚糖（CCS）阴道温敏性原位凝胶的处方,并对其体外性质进行考察。方法:拟定CCS质量分数为1.0%,以pH 4.2乳酸-乳酸钠为缓冲体系,在单因素试验的基础上,以胶凝温度(Tgel)为评价指标,以正交试验优化泊洛沙姆407（P407）、泊洛沙姆188（P188）、甘油及聚卡波菲（PCP）的用量。对最佳处方制备的CCS温敏性原位凝胶的pH、胶凝时间、黏度及体外释药特性进行考察。结果:优化的最佳处方为18%P407,5%P188,5%甘油及0.4%PCP。最佳处方制备的CCS温敏性原位凝胶平均Tgel为29.5℃,pH为4.12,胶凝时间为22.6 s,在8个温度单位内完成黏度的增加,体外释药符合一级动力学过程,且主要由基质溶蚀控制。结论:CCS温敏性原位凝胶体外性质符合阴道给药制剂的要求,并可迅速发生相转变,可望在阴道局部发挥缓释长效作用。     

参黄阴道用温敏原位凝胶的制备及质量评价

目的:制备参黄阴道用温敏原位凝胶并对其进行评价。方法:以泊洛沙姆407和泊洛沙姆188为基质,制备参黄阴道用温敏原位凝胶。考察原位凝胶经模拟阴道液稀释前后的黏度随温度变化曲线和胶凝温度,采用无膜释放法评价凝胶的体外释放,通过阴道刺激性试验观察原位凝胶的安全性。结果:所得制剂满足阴道可注入性和体内凝胶性能,对阴道无刺激性,药物释放由凝胶溶蚀来决定。结论:参黄阴道用温敏原位凝胶工艺可行,符合临床阴道局部用药物要求。     

复方盐酸苯海拉明凝胶的制备与质量控制

目的 研制复方盐酸苯海拉明凝胶,并建立其质量控制方法. 方法 以卡波姆作为凝胶基质,制备复方盐酸苯海拉明凝胶,采用高效液相色谱法进行含量测定. 结果 制备的凝胶均匀细腻,稳定性好;盐酸苯海拉明检测浓度在100～500 μg• mL^-1 范围内线性关系良好（r＝0.999 9）,平均回收率为100.41%,RSD＝0.87%;地塞米松磷酸钠检测浓度在10～50 μg•mL^-1范围内线性关系良好（r＝0.999 4）,平均回收率为100.96%,RSD＝1.15%. 结论 该凝胶制备工艺简单,质量稳定,质量控制方法准确可靠.     

高效液相色谱法测定奥硝唑凝胶中奥硝唑的含量

目的 采用高效液相色谱(HPLC)法测定奥硝唑凝胶中奥硝唑的含量. 方法 采用ODS C₁₈(4.6 mm×150 mm,5 μm) 的色谱柱;流动相：乙腈－水（20：80）,检测波长：312nm,流速：1 mL•min^-1,塞克硝唑为内标. 结果 奥硝唑浓度在0.63～20.00 μg•mL^-1范围内,峰面积与峰面积/内标比值具有良好线性关系,r＝0.999 9,平均回收率100.2%,RSD=1.2%. 结论 该法建立的含量测定方法 操作简便, 结果 准确、灵敏.     

地塞米松磷酸钠温度敏感原位凝胶的特性研究

本文以泊罗沙姆PluronicF127为温度敏感原位凝胶材料，考察了PluronicF127与PluronicF68不同浓度处方对地塞米松磷酸钠温度敏感原位凝胶的胶凝温度、相转变温度、凝胶强度、稳态黏度、溶蚀和药物释放行为等特性的影响。采用试管倒转法测定胶凝温度；旋转流变仪测定相转变温度、弹性模量、稳态黏度等流变学参数；无膜溶出法测定凝胶的溶蚀行为；HPLC测定地塞米松磷酸钠的释放度。结果表明，随着处方中F127浓度的增高，凝胶的胶凝温度和相转变温度降低，黏度和弹性模量增加，溶蚀速率和药物释放速率减慢；而处方中F68对凝胶特性的影响与F127相反。温度敏感原位凝胶在低温时为牛顿流体，黏度很小；随着温度升高，黏度增大；当增至相转变温度附近，表现出典型的假塑性流体特征；药物释放速率受控于凝胶溶蚀速率，二者遵循零级动力学方程。处方中含F127 22.5% / F68 2.5%的地塞米松磷酸钠温度敏感原位凝胶的性质与临床治疗要求基本吻合，有望在临床中获得应用。     

温敏壳聚糖凝胶共混环糊精对布洛芬的体外缓释性能

目的研究壳聚糖/甘油磷酸钠（CS/GPS）温敏性水凝胶共混β-CD包合物对药物的缓释性能。方法试管倒置法研究不同配比的CS/GPS温敏凝胶化性能;饱和水溶液法制备布洛芬/β-CD包合物,红外光谱表征包合物;紫外分光光度法测定包合物载药量和药物的累积释放度。结果体积配比5/1的2%CS/56%GPS体系（pH6.9）在37℃下可实现快速凝胶化。分别以布洛芬和布洛芬/β-CD包合物为模型药物,考察在温敏凝胶中的缓释行为,载有布洛芬凝胶24h药物累积释放度为81.5%,载有布洛芬/β-CD包合物凝胶累积释放度为69.1%。而24h布洛芬原药累积释放度为98.1%,布洛芬/β-CD包合物的累积释放度为82.2%。结论温敏性凝胶共混β-CD包合物,比单纯使用凝胶包埋药物或β-环糊精包合对药物具有更加明显缓释效果。CS/GPS凝胶体系有望作为温度敏感性给药系统的理想载体。     

氯霉素温敏型眼用原位凝胶的研制

目的制备氯霉素泊洛沙姆眼用原位温敏型凝胶并建立其质量控制方法。方法以泊洛沙姆P407和P188为温敏材料,通过测定溶液-凝胶相转变温度优化处方;采用紫外分光光度法测定氯霉素含量。结果氯霉素温敏型原位凝胶的胶凝温度随P407浓度增大而降低,随P188浓度增加先升高后降低,模拟泪液的稀释可使胶凝温度升高,建立了泪液稀释后相变温度与泊洛沙姆浓度的拟合方程,经Design-Expert软件优化出的氯霉素温敏型原位凝胶最佳处方为25%P407和4.19%P188;优化处方在29.5℃时为自由流动的液体,泪液稀释后在34.6℃能够发生相变形成凝胶。结论该眼用温敏凝胶符合眼部应用要求,体现出良好的应用前景。     

高效液相色谱法测定右旋布洛芬凝胶中右旋布洛芬的含量

目的 建立高效液相色谱（HPLC）法测定右旋布洛芬凝胶中右旋布洛芬含量. 方法 采用Hypersil ODS2色谱柱（4.6 mm×250 mm,5 μm）;流动相：乙腈 水（用磷酸调节pH值至3.0）（58：42）;检测波长：263 nm;流速1.0 mL•min ^-1;柱温：35 ℃. 结果 右旋布洛芬在25.1～251.0 μg •mL^-1范围内,线性关系良好,r＝0.999 9. 平均回收率为101.6%（n＝9）. 结论 该方法简便,快速,准确,重复性好,可用于该制剂的质量控制.     

更昔洛韦壳聚糖纳米粒眼用温敏型原位凝胶的制备与体外释放度研究

目的：制备更昔洛韦壳聚糖纳米粒眼用温敏型原位凝胶并考察其体外释放行为。方法：以离子交联化法制备更昔洛韦壳聚糖纳米粒,考察纳米粒的粒径、包封率等指标,同时观察纳米粒形态,测定纳米粒混悬液的pH及电位等。通过冷溶法将温敏材料溶于混悬液,制备温敏型原位凝胶,并采用星点设计一效应面法优化凝胶制备处方工艺,以人工模拟泪液为释放介质,考察制剂的体外释放特性。结果：更昔洛韦壳聚糖纳米粒呈球形,外观均匀圆整,分散性较好,平均粒径为（208．1±20）nm,多分散指数为0．171±0．030,平均包封率为（16．7±1．35）％,zeta电位为（27。36±2．0）mV;所得温敏型原位凝胶室温下为半透明具蓝色乳光的液体,体温下转变为半固体凝胶。凝胶中更昔洛韦缓释效果较好,其释放在0～4h符合一级释药动力学过程,4h之后符合零级动力学过程。结论：更昔洛韦壳聚糖纳米粒温敏型原位凝胶的胶凝效果良好,缓释作用明显,制备工艺简单可行。     

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.