Physicochemical Characterization of L-691, 121, a Potent and Selective Class III Antiarrhythmic Agent

The physicochemical properties of the novel antiarrhythmic agent L-691, 121 [methanesulfonamide, N- (1'- (2- (5-benzofirazanyl)ethyl)-3, 4-dihydro-4-oxospiro(2H-1-benzopyran-2, 4'-piperdin)6-yl), hydrochloride] have been studied, with particular emphasis on the stability, solubility, and dissolution properties of the drug. Solubility data in the pH range 0.5 to 11 show several distinct regions which are consistent with the existence of dicationic, cationic, neutral, and anionic forms of the drug. Dissolution studies were carried out using a continuous flow system which employed a conductance flow cell to monitor dissolved drug concentration. It is shown that the surface area of the drug is an important property in determining the dissolution rate. Solution stability studies indicate that the drug is prone to undergo a base-catalyzed elimination reaction which produces an N-dealkylated product. The preformulation data are used to develop intravenous and oral dosage forms suitable for clinical use.     

Physicochemical Characterization of YJA20379-8, a New Proton Pump Inhibitor

The physicochemical properties of the potent reversible proton pump inhibitor YJA20379-8, 3-butyryl-4-[(R)-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, were studied. YJA20379-8 is essentially nonhygroscopic pale yellowish crystalline powder. It is practically insoluble in water, and its lipid solubility is high. The pH solubility profile exhibits an L-shaped curve, indicating YJA20379-8 is a basic substance having a soluble ionized form in acidic conditions. This is consistent with the result of an experiment to determine pK_a. The solid-state stability study shows that YJA20379-8 is stable at various temperatures and humidities, but is decomposed by light.     

L-色氨酸分子印迹膜的表征、识别性能及识别机理

以L-色氨酸为模板分子,甲基丙烯酸为功能单体,聚砜为基膜,采用紫外光接枝法制备L-色氨酸手性分子印迹固膜.用扫描电镜和原子力电子显微镜对固膜的形貌进行表征,并对其特异性吸附性能及识别机理进行研究.固膜的手性分离因子高达4.1,由Scatchard模型分析分子印迹固膜与模板分子之间的结合作用力以氢键作用为主.     

Synthesis,Characterization, and Radiolabeling of Heterocyclic Bisphosphonate Derivative as a Potential Agent for Bone Imaging

1-Hydroxy-2-(2-pyridyl)ethanedisphosphonic acid monosodium salt (HPEDP) was prepared and labeled with ^99mTc using two different reducing agents: SnCl₂·2H₂O and NaBH₄; NaBH₄ gave better results. The radiochemical purity of ^99mTc(NaBH₄)-HPEDP was 96 ± 4%, and the complex was stable in vitro for 6 h. The in vivo biodistribution studies performed in mice show highly selective uptake of the labeled compound in the skeletal system and rapid elimination via the urinary pathway. The maximum bone uptake was 32.3 ± 2.1% ID/organ.     

Luminescent Carbon Nanodots Doped with Gadolinium (III): Purification Criteria,Chemical and Biological Characterization of a New Dual Fluorescence/MR Imaging Agent

Carbon Dots (CDs) are luminescent quasi-spherical nanoparticles, possessing water solubility, high biocompatibility, and tunable chemical and physical properties for a wide range of applications, including nanomedicine and theranostics. The evaluation of new purification criteria, useful to achieve more reliable CDs, free from the interference of artifacts, is currently an object of debate in the field. Here, new CDs doped with gadolinium (Gd (III)), named Gd@CNDs, are presented as multifunctional probes for Magnetic Resonance Imaging (MRI). This new system is a case of study, to evaluate and/or combine different purification strategies, as a crucial approach to generate CDs with a better performance. Indeed, these new amorphous Gd@CNDs display good homogeneity, and they are free from emissive side products. Gd@CNDs (7–10 nm) contain 7% of Gd (III) w/w, display suitable and stable longitudinal relaxivity (r₁) and with emissive behavior, therefore potentially useful for both MR and fluorescence imaging. They show good biocompatibility in both cellular and in vivo studies, cell permeability, and the ability to generate contrast in cellular pellets. Finally, MRI recording T₁-weighted images on mice after intravenous injection of Gd@CNDs, show signal enhancement in the liver, spleen, and kidney 30 min postinjection.     

钠基膨润土-AM-AA共聚复合型净水剂的制备及表征

为了改善膨润土的吸附性能和使用性能,文中以钠基膨润土为主体原料,进行了丙烯酰胺(AM)和丙烯酸(AA)聚合制备钠基膨润土-聚丙烯酰胺-聚丙烯酸复合物的研究,并通过对产品和原料进行X射线衍射(XRD)、红外光谱(FT-IR)、扫描电镜(SEM)和热重表征等表征分析,探讨了聚合机理。结果表明,丙烯酰胺和丙烯酸插层进入膨润土层间,在层间发生了聚合反应,所制备的复合物呈现类似吸水树脂的物理形态,在水中不发生解离。复合新型净水剂对Pb2+离子的吸附性能随着膨润土含量的提高而增加,且明显优于钠基膨润土。     

Physicochemical Characterization of Phenobarbital Polymorphs and Their Pharmaceutical Properties

Abstract

Simple and reproducible methods of preparing six modifications (forms A, B, C (monohydrate), D (dioxane solvate), E (hemihydrate) and F of phenobarbital were established from those previously reported. The physicochemical properties of these modifications were measured using X-ray diffractometry, Fourier-transformed infrared spectrophotometry, differential scanning calorimetry, thermogravimetry, scanning electron microscopy, solubility and others. The dissolution properties of all modifications in JP XI, 1st fluid (pH 1.2) were evaluated at 37°C containing 0.5% gelatin to prevent polymorphic transformation during the test. Forms A and D showed comparatively higher solubilities among all modifications. The tapping rate constants (k) of all crystal forms were estimated based on Kuno's equation, the k value for form F being the largest, whereas that of form D, the smallest, and the order of k of magnitude of the constant was F > B > E > C > A > D. The tablet hardness after compression at 1000 kg/cm² depended on the polymorphic form. Form D was the hardest, while forms B and F were the softest, in the order D > A > C > E > B = F.     

二臂超支化聚羧酸减水剂的合成表征及性能

以氯化亚砜和甲氧基聚乙二醇(MPEG)为原料合成氯代甲氧基聚乙二醇(Cl-MPEG),对乙醇胺表面的氨基进行聚乙二醇(PEG)长链接枝,通过丙烯酰氯进一步引入双键合成二臂超支化聚氧乙烯醚大单体(TAHBPE)。将TAHBPE与丙烯酸小单体采用水溶液自由基共聚法合成二臂侧链超支化型聚羧酸减水剂(TAHB-PCEs)。采用红外光谱、核磁共振、质谱、凝胶渗透色谱对合成过程的中间和最终产物进行了结构表征。结果表明,成功合成了Cl-MPEG,TAHBPE和TAHB-PCEs。净浆流动度和流变性测试结果表明,TAHB-PCEs的净浆流动度达到298.5 mm,屈服应力和黏度均小于传统梳型聚羧酸减水剂。通过表面张力、接触角对TAHB-PCEs的分散作用机理进行了探讨,保持聚羧酸减水剂的羧酸根密度不变、缩短侧链长度、增大侧链密度可降低其表面张力和表面能,有利于其在水泥表面的润湿,达到更好的减水分散性能。     

Selective CXCR4+ Cancer Cell Targeting and Potent Antineoplastic Effect by a Nanostructured Version of Recombinant Ricin

Under the unmet need of efficient tumor‐targeting drugs for oncology, a recombinant version of the plant toxin ricin (the modular protein T22‐mRTA‐H6) is engineered to self‐assemble as protein‐only, CXCR4‐targeted nanoparticles. The soluble version of the construct self‐organizes as regular 11 nm planar entities that are highly cytotoxic in cultured CXCR4⁺ cancer cells upon short time exposure, with a determined IC50 in the nanomolar order of magnitude. The chemical inhibition of CXCR4 binding sites in exposed cells results in a dramatic reduction of the cytotoxic potency, proving the receptor‐dependent mechanism of cytotoxicity. The insoluble version of T22‐mRTA‐H6 is, contrarily, moderately active, indicating that free, nanostructured protein is the optimal drug form. In animal models of acute myeloid leukemia, T22‐mRTA‐H6 nanoparticles show an impressive and highly selective therapeutic effect, dramatically reducing the leukemia cells affectation of clinically relevant organs. Functionalized T22‐mRTA‐H6 nanoparticles are then promising prototypes of chemically homogeneous, highly potent antitumor nanostructured toxins for precise oncotherapies based on self‐mediated intracellular drug delivery.     

聚丙烯成核剂TSD的制备与表征

利用钛酸四异丙酯、对叔丁基苯甲酸和正硅酸乙酯制备了一种新型成核剂三(对叔丁基苯甲酰氧基)-硅氧烷基-钛(TSD).利用热重分析(TG)考察了成核剂的热稳定性,采用X射线衍射分析(XRD)、差示扫描量热法(DSC)和偏光电子显微镜分析法(PLM)对聚丙烯(PP)的晶型及结晶行为进行了考察并测试了聚丙烯的力学性能和维卡软化...     

二氧化硅消光剂的合成与表征

为了获得性能指标符合消光剂要求的二氧化硅产品,通过正交实验L16(45)对沉淀法合成二氧化硅的过程进行优化,研究各因素对二氧化硅中位径、吸油值的影响规律,利用X射线衍射、扫描电镜对二氧化硅粒子的结构、形貌进行表征。结果表明,制备的二氧化硅为无定形产物,颗粒呈球形,一次颗粒粒径约为30 nm,各项指标与进口产品相近。     

含氟气湿反转剂的合成与表征

采用乳液聚合的方法合成了含氟丙烯酸酯聚合物乳液。红外光谱(FT-IR)对其结构进行分析,发现所有单体参与了反应,产物呈现共聚物结构。接触角测量结果显示,增加含氟单体的含量或应用含氟烷基侧链长的含氟单体合成聚合物,其产生的疏水性较强。含氟丙烯酸酯聚合物处理岩心后,蒸馏水、油田污水、十六烷、原油的接触角分别由2.52°、10.62°、2.2°和35.35°增加到139.79°、122.31°、65.46°和85.68°,表明岩心表面的润湿性由强液湿转变为气湿。毛细管上升实验结果表明,聚合物可以使气/水体系和油/气体系中的接触角分别由60°和32.86°增加到118.36°和76.11°。因此,合成的聚合物可以使毛细管的润湿性发生气湿反转。     

Physicochemical Characterization and Evaluation of Buccal Adhesive Tablets Containing Omeprazole

The objective of this study was to develop an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for the omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethylcellulose (HPMC) was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Among alkali materials, only magnesium oxide could be an alkali stabilizer for omeprazole buccal adhesive tablets due to its strong waterproofing effect. Croscarmellose sodium enhanced the release of omeprazole from the tablets; however, it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. The tablet composed of omeprazole/sodium alginate/HPMC/magnesium oxide/croscarmellose sodium (20/24/6/50/10 mg) could be attached on the human cheek without disintegration, and it enhanced the stability of omeprazole in human saliva for at least 4 h and gave fast release of omeprazole. The plasma concentration of omeprazole in hamsters increased to a maximum of 370 ng/ml at 45 min after buccal administration and continuously maintained a high level of 146–366 ng/ml until 6 h. The buccal bioavailability of omeprazole in hamsters was 13.7% ± 3.2%. These results demonstrate that the omeprazole buccal adhesive tablet would be useful for delivery of an omeprazole that degrades very rapidly in acidic aqueous medium and undergoes hepatic first-pass metabolism after oral administration.     

Mucoadhesive and Physicochemical Characterization of Carbopol-Poloxamer Gels Containing Triamcinolone Acetonide

The viscosity and bioadhesive property of Carbopol-Poloxamer gels containing triamcinolone acetonide to mucosa were tested according to various concentrations of Carbopol gels of various pH. The increase in Carbopol concentration caused increased viscosity and bioadhesiveness. The neutralization of pH in various concentrations of Carbopol gels showed the increased viscosity, showing the highest viscosity and highest bioadhesiveness when neutralized to pH 6. A relationship between the viscosity and bioadhesive strength was shown from the neutralized Carbopol gels. The physicochemical interactions between triamcinolone acetonide and polymers were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectrophotometry. According to FTIR and XRD studies, the drug did not show any evidence of an interaction with the polymers used and was present in an unchanged state.     

Physicochemical Characterization and Evaluation of Buccal Adhesive Tablets Containing Omeprazole

The objective of this study was to develop an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for the omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethylcellulose (HPMC) was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Among alkali materials, only magnesium oxide could be an alkali stabilizer for omeprazole buccal adhesive tablets due to its strong waterproofing effect. Croscarmellose sodium enhanced the release of omeprazole from the tablets; however, it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. The tablet composed of omeprazole/sodium alginate/HPMC/magnesium oxide/croscarmellose sodium (20/24/6/50/10 mg) could be attached on the human cheek without disintegration, and it enhanced the stability of omeprazole in human saliva for at least 4 h and gave fast release of omeprazole. The plasma concentration of omeprazole in hamsters increased to a maximum of 370 ng/ml at 45 min after buccal administration and continuously maintained a high level of 146-366 ng/ml until 6 h. The buccal bioavailability of omeprazole in hamsters was 13.7% ± 3.2%. These results demonstrate that the omeprazole buccal adhesive tablet would be useful for delivery of an omeprazole that degrades very rapidly in acidic aqueous medium and undergoes hepatic first-pass metabolism after oral administration.     

新型潜伏性M-DDM微胶囊固化剂的制备及表征

利用E-44环氧树脂对二氨基二苯基甲烷环氧树脂固化剂(DDM)进行了改性,合成了含有羟基的E-44-DDM固化剂(M-DDM)。以所合成的M-DDM粉体为囊芯、以2,4-甲苯二异氰酸酯(TD I)为壁材单体,采用界面聚合技术,首次成功制备了一种新型聚脲M-DDM微胶囊固化剂。该微胶囊固化剂粒径分布较窄,平均粒径约为2.54μm。囊壁是TD I与囊芯粉体表面的羟基通过加成聚合反应形成的,壁厚约为100 nm。所制备的微胶囊固化剂具有优良的固化性能和潜伏性能,可以在100℃使环氧树脂E-51在1 h内固化,并且其室温潜伏期可达6个月以上。     

纳米二氧化硅及载银抗菌剂制备与表征

在不同的醇溶剂环境中,采用水解法制备了粒径大小不同的纳／微米二氧化硅（SiO2）,研究了不同醇溶剂对SiO2粒子大小的影响。实验结果表明,随着醇溶剂分子量的增大,SiO2的粒径逐步增大。通过浸渍吸附和化学还原两步法成功制备了SiO2载银抗菌剂,并优化了制备工艺条件。抑菌实验检测显示,二氧化硅载银（SiO2／Ag）抗菌剂对金黄色葡萄球菌和大肠杆菌的抑菌圈大小分别为15．3mm和10．4mm。     

高效复合类发泡剂的制备及其性能研究

泡沫混凝土具有容重轻、自立性强及防渗性好等特点,是一种新型港口码头挡土墙回填材料,其中发泡剂的研制对泡沫混凝土的性能起着至关重要的作用。本文制备的发泡剂是以浓度为0.8%的α-烯基磺酸钠溶液为发泡剂母液,选取稳泡物质A、B、C和D对母液进行稳泡改性,并对泡沫性能进行分析研究。该发泡剂制备的泡沫表面光泽细腻,稳定性较好,其中发泡倍数为46.7倍,1 h沉降距为1.2 mm,1 h泌水量为15.7ml,将该发泡剂应用于挡土墙回填用泡沫混凝土,产品表现出了较好的力学性能和抗渗性能。     

咪唑封闭聚氨酯的制备及在纸张增强中的应用

以咪唑为封闭剂,1,6-己二异氰酸酯(HDI)、二羟甲基丙酸(DMPA)、双酚A、聚酯二醇为原料制备出阴离子封闭聚氨酯(ABPU)。用傅里叶变换红外光谱(FT-IR)、动态激光光散射(DLS)、透射电镜(TEM)分别对ABPU分子结构及乳胶粒形态进行了表征,研究了ABPU封闭率对纸张力学性能的影响。结果表明,增加ABPU封闭率,能明显提高纸张的强度指标,尤其是湿拉伸指数。产物分子结构中出现了羧基、咪唑环和聚氨酯结构;乳胶粒径与羧基含量密切相关,乳胶粒呈不规则的、具有核壳结构的球形。     

AOT表面修饰CdS纳米粒子的合成与表征

以AOT为表面活性剂,硫脲及乙酸镉为原料,磷酸二氢钾为相转移剂,分别在水相和有机相中制备了CdS纳米粒子.UV-Vis光谱表明,CdS纳米粒子具有明显的量子尺寸效应.FTIR光谱分析表明,水相中AOT分子的-S=O、-C-O、-C=O基团指向溶剂,-CH2-基团堆砌在CdS纳米粒子表面,而有机相中则相反.TEM测试结果表明,有机相球形CdS纳米粒子具有较好的自组装行为,其尺寸为5～10nm且分布较窄.