光照对氧氟沙星葡萄糖注射液稳定性的影响

本文用十字交叉试验设计法考察ｐＨ值、光照强度和光照时间对氧氟沙星葡萄糖注射液稳定性的影响。结果表明：不同ｐＨ值的各组注射液，经强光照射后，其ｐＨ值、Ａ_４５０ｎｍ（有色物吸收值），对大肠杆菌［ＣＭＣＣ（Ｂ）４４１０３］的抗菌活性均没有明显改变（Ｐ＞０．０５），但氧氟沙星含量有所下降，杂质峰面积增加。后两者的变化受ｐＨ值影响最大，照射时间次之，光照强度影响最小。     

光照对芍药苷稳定性的影响

目的：考察光照对赤芍、白芍、牡丹皮中芍药苷稳定性的影响。方法：在有、无光照条件下,加热一定时间,采用高效液相色谱法测定芍药苷的含量变化。结果：在光照条件下,芍药苷稳定性降低。结论：光照加速芍药苷分解。     

天然虾青素的提取、纯化研究进展

近年来虾青素的提取、纯化工艺在不断优化。微波、超声、超临界流体萃取术、生物酶法等技术可显著增加提取量。柱层析法、高效液相色谱法是最常见的纯化手段。该文综述了虾青素的提取、纯化研究进展,以期为提取、纯化方法的联合利用提供参考,促进虾青素的高效获取。     

考察野黄芩素和白杨素的溶解度和稳定性

目的:考察野黄芩素和白杨素在纯水溶液中的溶解度以及在HBSS溶液中的稳定性,为药物的代谢研究和样品制备提供依据。方法:以药物在50%甲醇中的溶解度为标准,建立药物在纯水中的溶解度曲线,并考察药物在HBSS溶液中含量随时间变化的曲线,作为判断药物稳定性的依据。野黄芩素和白杨素的含量采用高效液相色谱法进行测定。结果:野黄芩素在0μM～102.4μM范围内可完全溶解,在7 d内0μM～25μM范围性质稳定。白杨素在0～25.6μm范围内可完全溶解,在2 d内0μM～25μM范围性质稳定,在7 d内0μM～12.5μM性质稳定。结论:野黄芩素和白杨素均在20μM的HBSS溶液溶解性和稳定性最好。     

不同光照对盐酸左氧氟沙星注射液稳定性的影响

目的 :探讨不同光源照射对盐酸左氧氟沙星注射液稳定性的影响程度。方法 :分别选择紫外光、太阳光、自然光作为照射光源 ,观察盐酸左氧氟沙星注射液在3种光源下照射不同时间后的光谱变化并测定其含量 ,另用薄层色谱法检查有无分解产物生成。结果 :盐酸左氧氟沙星注射液在3种光照下均有分解 ,以太阳光照射下分解最快 ;以薄层色谱法检查出降解产物的Rf值为0 .72。结论 :盐酸左氧氟沙星注射液应避开紫外光、太阳光、自然光保存。     

虾青素对db/db小鼠血脑屏障损伤和认知障碍的影响及机制

目的 明确虾青素(astaxanthin,ASTA)对高血糖引起的血脑屏障(blood brain barrier,BBB)损伤和认知障碍的影响及机制。方法 8周龄db/db雄性小鼠给予不同剂量(5、10、20 mg·kg^-1)的ASTA灌胃,持续4周。Western blot检测小鼠脑部CD31,闭合小环蛋白-1(zonula occluden-1,ZO-1)和紧密连接蛋白5(claudin5,Cldn5)的蛋白表达,酶联免疫吸附测定(enzyme-linked immunosorbent assay,ELISA)检测脑部炎症因子白介素-6(interleukin-6,IL-6),白介素-1β(interleukin-1β,IL-1β)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的水平。水迷宫检测各组小鼠的学习记忆功能。结果 db/db小鼠脑部CD31,ZO-1和Cldn5蛋白表达明显低于db/m小鼠,10和20 mg·kg^-1ASTA灌胃,能明显增加db/db小鼠脑部CD31,ZO-1和Cldn5蛋白的...     

光照对核黄素磷酸钠静脉滴注过程中稳定性的影响

<正>核黄素即维生素B2,是人体重要微量元素之一,在能量代谢中起关键作用,临床上用于核黄素缺乏引起的口角炎、唇炎、舌炎、眼结膜炎及阴囊炎等疾病的治疗,近年来研究发现其在感染、烧伤、发热、肿瘤放化疗等方面亦有很好的辅助治疗作用,所以临床应用越来越广泛。因其结构特点,见光易变质,药品说明书要求采取皮下、肌肉、静脉注射的给药方     

蛇床子素稳定性影响因素及其在不同介质中的稳定性研究

目的对蛇床子素原料药进行稳定性考察,为进一步设计高效稳定的蛇床子素的口服或经皮给药系统提供研究基础。方法采用高效液相色谱法测定蛇床子素在37℃水、生理盐水和不同pH值的缓冲溶液中含量随时间的变化;以及在高温、高湿、强光照射条件下蛇床子素的含量作为考察指标,对蛇床子素原料药进行试验。结果在37℃下,在纯净水、生理盐水、0.1 mol/L的HCl溶液和pH2.0、4.5、6.8、7.4、8.0的缓冲溶液中,蛇床子素的含量在24 h内分别下降7.6%、8.8%、13.7%、5.5%、5.4%、7.4%、7.2%、5.8%;第10天,在高温、高湿和强光因素的影响下,与0天相比,蛇床子素的相对含量分别为(102.3±1.2)%,(93.2±1.0)%和(100.6±1.5)%。结论蛇床子素在水溶液中化学稳定性较差,尤其是在强酸性溶液中;湿度条件对于蛇床子素原料药的稳定性影响较大。本研究能够为蛇床子素新型给药系统的处方设计提供基础。     

pH对亮菌甲素稳定性的影响

采用经典恒温法考察亮菌甲素在不同pH水溶液中的稳定性。结果表明亮菌甲素在pH3时最稳定，而在强酸及中性偏碱条件下不稳定，pH8时的t0.9仅为2h。     

Effect of light and heat on the stability of montelukast in solution and in its solid state

The chemical stability of montelukast (Monte) in solution and in its solid state was studied. A simultaneous measurement of Monte and its degradation products was determined using a selective HPLC method. The HPLC system comprised a reversed phase column (C18) as the stationary phase and a mixture of ammonium acetate buffer of pH 3.5 and methanol (15:85 v/v) as the mobile phase. The UV detection was conducted at 254 nm. Monte in solution showed instability when exposed to light leading to the formation of its cis-isomer as the major photoproduct. The rate of photodegradation of Monte in solution exposed to various light sources increases in the order of; sodium相似文献   

光和热对盐酸氯丙嗪注射液稳定性的影响

目的 研究盐酸氯丙嗪注射液在光和热作用下的稳定性.方法 采用恒温加速试验和高温光照试验进行考察.结果 高温条件下,盐酸氯丙嗪注射液的降解符合一级动力学规律;光照条件下,符合零级动力学规律.结论 光照下提高温度可增大降解速率,降解速率的大小与波长有关.     

Influence of light and heat on the stability of rotundine sulfate injection.

The influence of both light and heat on the stability of rotundine sulfate injection was studied. Results show that in experiments with either isothermal heating or exposure to light at high temperatures, the drug coloration rate obeys zero-order kinetics. The total rate constant, k(total), caused by both light and heat can be divided into two parts: k(total)=k(dark)+k(light), where k(dark) and k(light) are the rate constants caused by heat and light, respectively. The k(light) can be expressed as k(light)=A(light)exp(-E(a,light)/RT)E, where E is the illuminance of light, A(light) is an experimental constant related to light sources, and E(a,light) is an experiment constant. Because the form of k(light) is similar to the Arrhenius equation, it is suggested that E(a,light) might be the observed activation energy of the rate-determining step of the subsequent processes of the photochemical reaction. This viewpoint is supported by the fact that E(a,light) is independent of light sources.     

Effect of lipid types on physicochemical characteristics,stability and antioxidant activity of gamma-oryzanol-loaded lipid nanoparticles

In the present study gamma-oryzanol, an antioxidant, was incorporated into three different types of solid lipid: wax, triglycerides, a mixture of glycerides as solid lipid nanoparticles (SLN) and liquid lipid (Miglyol 812) as nanoemulsion (NE). Instability was found only from NE due to its significant increase in particle size and decreased entrapment efficiency (%EE) at a storage temperature of 45°C. Solid lipid type in SLN plays an important role only on %EE, but not chemical stability. A decrease in crystallinity of SLN was observed with the incorporation of gamma-oryzanol and low recrystallization index were found with two glycerides-based SLN. The in vitro release studies demonstrated that a biphasic release pattern fitted well with the Higuchi model of SLN formulations. In comparison, nearly constant release was observed in NE comprised of similar composition. Wax-based SLN demonstrated the lowest cytotoxicity. NE, wax-based SLN and a mixture of glycerides-based SLN were considered to enhance the antioxidant activity of gamma-oryzanol.     

天然虾青素的超级抗氧化活性及其应用

本文综述了天然虾青素的来源、超级抗氧化活性和生物安全性 ,以及在医药、保健食品和饲料工业中的应用 ,并对国内虾青素的产业化前景进行了展望。     

Disodium disuccinate astaxanthin (Cardax): antioxidant and antiinflammatory cardioprotection

Disodium disuccinate astaxanthin (Cardax), DDA) has cardioprotective effects in the rat, rabbit, and canine models of experimental infarction. It is highly effective by parenteral administration in subchronic and acute dosing regimens. Unpublished data in rats suggest that oral cardioprotection is also readily achievable. DDA-induced myocardial salvage in the canine can reach 100% with a 4-day subchronic dosing regimen. At a single i.v. dose DDA is cardioprotective, when given 2 h before experimental coronary occlusion, but the protection is on the average two-thirds of that achieved with the subchronic regimen in dogs. In conscious animals DDA has no effects on hemodynamic parameters. The primary mechanism of cardioprotection appears to be antioxidant activity involving direct scavenging of superoxide anion, the lynchpin radical in ischemia-reperfusion injury. In addition, modulation of serum complement activity, as well as the reduction in the levels of C-reactive protein (CRP) and the membrane attack complex (MAC) in infarcted tissue suggest a significant antiinflammatory component in the mechanism of cardioprotective action of DDA. Stoichiometric binding of the meso-form of the compound to human serum albumin (HSA) has been demonstrated in vitro. This binding capacity overcomes the supramolecular assembly of the compound in aqueous solution, which by itself improves the stability and shelf life of aqueous formulations. Non-esterified astaxanthin readily enters cardiac tissue after either oral or parenteral administration, providing a reservoir of a cardioprotective agent with a significant half-life due to favorable ADME in mammals. Due to the well-documented safety profile of non-esterified astaxanthin in humans, disodium disuccinate astaxanthin may well find clinical utility in cardiovascular indications in humans following successful completion of preclinical and clinical pharmacology and toxicology studies.     

Effect of multiple freeze-thaw cycles of cytoplasm samples on the activity of antioxidant enzymes

INTRODUCTION: In this paper the activity of cytoplasmatic antioxidant enzymes after multiple freeze-thaw cycles of samples of cytoplasm was assayed in order to characterise the limits that would be necessary to impose on experimental design. METHODS: The activities of antioxidant enzymes in samples of rat liver cytoplasm were evaluated after 1, 2, 3, 4, 5, 10 and 15 freeze-thaw cycles. The activity of antioxidant enzymes was determined by standard methods developed for this purpose. RESULTS: The most resistant against freeze-thaw stress was catalase; even 15 freeze-thaw cycles did not change its activity. The remaining enzymes tested revealed a significant loss in their activity after 4-5 freeze-thaw cycles. The most sensitive was glutathione S-tranferase; its activity was significantly decreased after 3 thaw cycles. DISCUSSION: The data presented may be helpful in designing experiments in which assay of antioxidant enzymes is a part.     

Effect of heat processing on the chemical constituents and NO-suppressing activity of Bletilla Tuber

Journal of Natural Medicines - Bletilla Tuber (dried tuber of Bletilla striata) is used as an astringent hemostatic medicine for the treatment of ulcers, bleeding, and burns in traditional Chinese...