Agglomeration behavior of petal-shaped cerium carbonate with different operating conditions

Agglomeration phenomenon can often be observed during the fabrication process of petal-shaped,nano-sized Ce_2(CO_3)_3 powders. This kind of powder was produced by liquid-phase precipitation method with the template agent of polyallylamine hydrochloride(PAH). In this study, the effects of the polymer concentration, pH value, and stirring speed on the agglomeration phenomenon of cerium carbonate were investigated. On the condition that the concentration of PAH is 0.9 g·L^-1,the pH value of the adjusting solution is 3-4. the final pH value is 8-10, and the stirring speed is 300-400 r·min^-1, it is found that the agglomeration phenomenon of Ce_2(CO_3)_3 particles can be greatly prevented and the regular petalshaped particles are formed.     

Preparation of ZnFe2O4–chitosan-doxorubicin hydrochloride nanoparticles and investigation of their hyperthermic heat-generating characteristics

In this study, the structural morphology and magnetic effects of magnetic ZnFe₂O₄ nanoparticles loaded with the cancer-fighting drug doxorubicin hydrochloride (DOX-HCl) were investigated. These nanoparticles have been found to have potential biomedical applications in targeted drug-delivery systems. The zinc ferrite nanoparticles were prepared by a chemical coprecipitation method and coated with chitosan. The nanoparticles were loaded with DOX-HCl and their surfaces improved by folic acid, which can be activated to target specific cancer cells. The specific absorption rate (SAR) values of the ZnFe₂O₄–chitosan–DOX-HCl nanoparticles were investigated at a frequency of 200 kHz and 1.5 kA/m amplitude in order to obtain Brownian relaxation time parameters. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and ultraviolet–visible spectrophotometry (UV–vis) were used to characterize the bulk properties of these nanoparticles. In addition, the impact of the nanoparticles under an alternating current (AC) magnetic field and their heat-generation ability were investigated using an experimental setup. The average nanoparticle size was found to be 8.5 nm. Magnetic hysteresis loops confirmed the superparamagnetism of the nanoparticles. The saturation magnetization was 6 emu/g. UV–vis was used to measure the amount of drug loaded onto the nanoparticles. The amount of drug absorption was significantly higher after 12 h, totaling 75%. The specific absorption rate parameter was 80.66 W/g, and the Brownian relaxation time was 188×10⁻⁹ s.     

CdTe/CdS量子点荧光猝灭法测定盐酸西替利嗪

建立一种基于纳米材料的荧光性质测定盐酸西替利嗪含量的新方法,盐酸西替利嗪能使硫化镉包被的碲化镉核壳型量子点(CdTe/CdS QDs)发生规律性的荧光猝灭,研究二者相互作用的最佳条件,从而建立测定盐酸西替利嗪含量的方法。结果表明:盐酸西替利嗪的浓度在0.40~42μg/m L范围内有良好的线性关系(r=0.9992),检测限为2.50×10-2μg/m L,回收率为93.80%~97.00%。结论:此方法简便、快捷、可靠,适用于盐酸西替利嗪的含量测定。     

3,5-二氯-2-戊酮的合成研究

以α-氯-α-乙酰基-γ-丁内酯、固体光气为原料,N,N-二甲基哌啶盐酸盐为催化剂合成了3,5-二氯-2-戊酮。考察了催化剂种类、氮气通入速率、物料配比、滴加时间、滴加温度等因素对反应的影响。优化条件下,3,5-二氯-2-戊酮的含量94.0%,收率81.5%(以α-氯-α-乙酰基-γ-丁内酯计)。     

非水滴定法定量测定己二胺盐酸盐

建立了测定己二胺盐酸盐含量的非水滴定法。以高纯度冰醋酸为溶剂,0.2%结晶紫为指示剂,用0.1 mol/L高氯酸标准溶液滴定至己二胺盐酸盐溶液由紫色变为蓝色。分别采用电位滴定与指示剂两种指示终点的方法。结果表明:2种指示终点的方法无显著差异,相对平均偏差为0.047%～0.070%。该方法操作简单、准确可靠、滴定终点突跃明显,重现性好。     

Preparation and in vitro release behavior of urapidil hydrochloride loading into microspheres based on poly(L‐lactide)

Microencapsulation of the antihypertensive drug urapidil hydrochloride was investigated as a means of controlling drug release and minimizing or eliminating local side effects. Poly(L ‐lactide) (PLLA) microspheres were prepared using an alternative oil‐in‐water (O/W) solvent‐evaporation method such as the O/W cosolvent solvent‐evaporation method and O/W with various electrolytes added to the aqueous phase method. The surface morphology and the size of the microspheres were observed by scanning electron microscope. Meanwhile, the drug loading efficiency of microspheres and the in vitro release of urapidil hydrochloride from microspheres were performed. The release study indicated that the urapidil hydrochloride‐PLLA microspheres exhibited better sustained release capacity, and the kinetics of urapidil hydrochloride‐PLLA microspheres in vitro release could be described by the Higuchi equation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

3,5-二甲基-4-羟基苯甲腈的合成研究

以3,5-二甲基-4-羟基苯甲醛和盐酸羟胺为原料,分别在甲酸、乙酸和N,N-二甲基甲酰胺(DMF)中一步反应合成了3,5-二甲基-4-羟基苯甲腈。以DMF为溶剂的反应效果最好,最佳条件下收率达90%以上,粗品含量98%以上。     

2-氨基-5,7-二甲氧基-1,2,4-三嗪并[1,5-a]嘧啶的合成及工艺优化

2-氨基-5,7-二甲氧基-1,2,4-三嗪并[1,5-a]嘧啶的合成及工艺优化。以4,6-二甲氧基嘧啶-2-胺为主要原料,经两步反应制得2-氨基-5,7-二甲氧基-1,2,4-三嗪并[1,5-a]嘧啶;并考察了第二步合成工艺。通过熔点测定和1HNMR确证了2-氨基-5,7-二甲氧基-1,2,4-三嗪并[1,5-a]嘧啶;找到了最佳合成工艺,总收率81%。该合成方法具有反应条件温和、成本低、适合工业生产等优点。     

雷贝拉唑的合成

以2-羟甲基-4-(甲氧基丙氧基)-3-甲基吡啶盐酸盐为起始原料,经氯代、缩合反应"一锅法"制得2-{[3-甲基-4-(3-甲氧基丙氧基)-2-吡啶基]甲基亚磺酰基}-1H-苯并咪唑,再经氧化反应得到雷贝拉唑。     

盐酸贝那普利的合成进展

盐酸贝那普利是世界卫生组织推荐的一线抗高血压药物,是当前国际上血管紧张素转化酶抑制剂类抗高血压药物中临床疗效佳、安全性高、副作用小的一种手性药物。本文对近几年来盐酸贝那普利的合成方法进行了归纳总结,并且根据两个关键中间体合成方法的不同,即(3S)-3-氨基-2,3,4,5-四氢-2-氧代-1H-1-苯并氮杂卓-1-乙酸叔丁酯(中间体1)和R-2-羟基-4-苯基丁酸乙酯(中间体2)的不同,对其合成路线进行了综述,并评述了各自的优缺点。