scholarly journals Cocrystallization of Febuxostat with Pyridine Coformers: Crystal Structural and Physicochemical Properties Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lei Gao ◽  
Xianrui Zhang

Drug cocrystals and salts have promising applications for modulating the physicochemical properties and solubility of pharmaceuticals. In this study, a cocrystal and two salts of febuxostat (FEB) with pyridine nitrogen coformers, including 4, 4′-bipyridine (BIP), 3-aminopyridine (3AP) and 4-hydroxypyridine (4HP), were designed to improve the solubility of FEB. The single-crystal structures were elucidated, and their physical and chemical properties were investigated by IR, PXRD, and DSC. In addition, drug-related properties, including the solubility and powder dissolution rate were assessed. The solubility and powder dissolution studies showed that the FEB-BIP cocrystal and FEB-3AP salt have superior dissolution compared to FEB.

2015 ◽  
Vol 3 (31) ◽  
pp. 16120-16131 ◽  
Author(s):  
L. M. Acuña ◽  
F. F. Muñoz ◽  
C. A. Albornoz ◽  
A. G. Leyva ◽  
R. T. Baker ◽  
...  

The effect of Tb content and synthesis method on the physicochemical properties of nanostructured Tb-doped ceria spheres was studied. The nanostructured spheres contained more Tb as Tb3+ than conventionally prepared nanopowders.


2019 ◽  
Vol 11 (17) ◽  
pp. 44
Author(s):  
Bo Peng ◽  
Lu-Lu He ◽  
Jing Tan ◽  
Li-Ting Zheng ◽  
Jie-Ting Zhang ◽  
...  

The main nutrients in rice are starch, protein and lipids, and their contents and physicochemical properties have important effects on rice qualities. The aging process of rice is very complex, which not only changes physical and chemical properties, but also changes its physiological characteristics in rice grain. In this paper, the changes of physicochemical properties of its main nutrients (starch, protein and lipids) during storage were reviewed. At the same time, the effects of rice aging on its quality characters and the mechanism of rice aging were also discussed, which could provide reference for solving the problem of rice quality decline during storage.


2018 ◽  
pp. 15-21
Author(s):  
J Vasilev ◽  
R Zamogilniy ◽  
D Samokysh

An engineering technique was developed to determine the antifriction efficiency of emulsols during cold rolling according to their physicochemical properties. This method is based on the dimensionless exponent’s kсм, kвяз kэф and kотн.эф, taking into account, respectively, the influence of the chemical and physical properties of emulsols on the antifriction efficiency of the latter and the proposed dependencies for calculating rating of their antifriction efficiency. With the proposed method and criterion kотн.эф antifriction efficiency of 24 different emulsol it was investigated applied in cold rolling and the calculated rating antifriction their effectiveness. It is established that the high antifriction and washing efficiency of modern emulsols is achieved with a value of the kinematic viscosity of the latter at a level of 30-45 mm2/s and an increase in the saponification to 160-195 mg KOH/g.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Evgenia Uglova ◽  
Eugene Eremenko ◽  
Natalya Sikachyova ◽  
Kiril Kuzin

To increase the adhesion strength (wetting ability) of bitumen, and, consequently, reduce the likelihood of premature occurrence of defects formed on asphalt concrete coatings, it is necessary to use various kinds of surfactants that increase the adhesion ability of bitumen. Adhesive additives to road bitumens increase the mobility of the organic binder, help reduce the number of uncoated grains of mineral material, which facilitates the compaction of asphalt concrete mix. One of the problems of durability of asphalt concrete pavements is the lack of strong adhesion of the bitumen film to the surface of the mineral material. To increase this strength, various adhesive additives are used, which affect not only the adhesive properties of bitumen, but also its physical and chemical properties. The main task of the work is aimed at solving the issues of the influence of adhesive additives on the physicochemical properties of organic binders used in road construction. The quality assessment of the modified bitumen was carried out according to GOST 22245-90, which, at present, is guided by the selection of the composition of the asphalt concrete mixture. As a result of the study, effective adhesive additives were identified that contribute to the minimal change in the physicochemical properties of viscous road bitumen and possess thermal stability under prolonged exposure to elevated temperatures. Studies have shown that almost all adhesive additives not only improve the adhesive properties of organic binders to mineral materials, but also can alter and even worsen the physicochemical properties of the original organic binder, which can adversely affect the properties of asphalt concrete. The study used the original bitumen from only one manufacturer and the negative effect of adhesive additives may be due to the incompatible chemical composition of the adhesive additive with the group composition of bitumen and the mineralogical composition of the mineral material.


2018 ◽  
Vol 15 (5) ◽  
pp. 296 ◽  
Author(s):  
Bo Ruan ◽  
Pingxiao Wu ◽  
Huimin Wang ◽  
Liping Li ◽  
Langfeng Yu ◽  
...  

Environmental contextInteractions between microbes and minerals can influence geochemical reactions, and hence are of fundamental importance in natural environmental processes. We investigate the effects of Sphingomonas sp. on the structure and physicochemical properties of montmorillonite, a common clay mineral, and determine how this interaction influences the biodegradation of phenanthrene. The findings have profound impact on the clay-modulated biodegradation of organic compounds in the environment. AbstractWe investigate the effect of Sphingomonas sp. GY2B on the structure and physicochemical properties of montmorillonite (Mt). The simultaneous biodegradation of a polycyclic aromatic hydrocarbon compound, phenanthrene, was also monitored. After interaction with bacteria for 2 days, the increases of the specific surface area (SSA) and micropore volume, differences of the thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) patterns and the morphological changes revealed modification of the physicochemical properties and mineral surface. Although the interlayer spacing of Mt remained unchanged, the appearance and shift of several vibration peaks in the Fourier transform infrared (FTIR) spectra confirmed the structural changes of Mt arising from bacterial activities. Concentrations of the major elements of montmorillonite changed greatly in the aqueous solution, especially Si, Al, Fe and Ca. Based on the analyses of X-ray diffraction (XRD) and FTIR, these changes were mainly ascribed to the formation of precipitates and minerals in the biotic experiment. Changes in the release rate of different elements also substantiated that the GY2B strain has a considerable impact on the dissolution of montmorillonite. Additionally, a preferential release of Si and the 27Al and 29Si cross-polarisation magic-angle spinning nuclear magnetic resonance (CP/MAS NMR) spectra of bacteria-untreated samples demonstrated that tetrahedral sheets were preferentially destroyed and octahedral sheets in montmorillonite were dissolved. These results showed that microorganisms can greatly affect the physical and chemical properties of clay minerals in the clay-modulated biodegradation of hydrophobic organic contaminants. This study provides valuable insight into the clay-modulated microbial remediation of organic pollutants in the environment.


2019 ◽  
Vol 26 (38) ◽  
pp. 6896-6914 ◽  
Author(s):  
Diana M. Bobrowska ◽  
Piotr Olejnik ◽  
Luis Echegoyen ◽  
Marta E. Plonska-Brzezinska

: This article presents a brief review of the knowledge concerning onion-like carbons (OLCs). These nanostructures are some of the most fascinating carbon forms due to their unusual structure and physico-chemical properties. Generally, OLCs consist of a hollowspherical fullerene core surrounded by concentric graphitic layers with increasing diameter. Nevertheless, they can have different size, shape and type of core, which determine their physicochemical properties. In this article, we review the most important literature reports in this area and briefly describe these nanostructures, their physical and chemical properties and their potential uses with a focus on biomedicine.


2021 ◽  
Vol 15 (1) ◽  
pp. 357-365
Author(s):  
Martin Luis S. Redor ◽  
Rui Zhang ◽  
Natthamet Wongsirichat ◽  
Ratchapin Laovanitch Srisatjaluk ◽  
Teeranut Chaiyasamut ◽  
...  

Introduction: There has been extensive research on bone substitutes and autogenous bone; however, little is known about their physical and chemical characteristics of torus mandibularis and palatinus. In the present study, the physical and chemical properties of tori bone and bone graft substitutes were examined. Microbial contamination of torus bone collected during surgery was also investigated. Objective: To investigate the physical and chemical properties of torus mandibularis and torus palatinus, and the microbial contamination of tori bone collected during surgery. Materials and Methods: Torus mandibularis and palatinus were collected from healthy patients by regular surgical procedure via bone collector and a stringent aspiration protocol. Physicochemical properties such as surface structure, elemental components and the crystalline structure of tori and common bone grafting substitutes (OraGRAFT, BioOss, Cerabone) were examined via SEM-EDS, X-Ray Diffractometry analysis, and calcium dissolution assay. The bacterial morphology and gram staining from the torus samples after the surgery were analyzed. Results: The surface structure of tori bone differed greatly from that of bone graft substitutes. An irregular and rough surface structure was found for tori, while bone graft substitutes presented a smooth but dry pattern. Elements found within tori were similar to those within bone graft substitutes; in all cases, carbon, oxygen, sodium, magnesium, phosphate, and calcium were seen. All samples showed high crystallinity, with the highest value in Cerabone, followed by Bio-oss, torus mandibularis, torus palatinus, and Oragraft. Calcium dissolution was highest on the first day in tori samples, whereas it was constantly released until the seventh day in other bone grafts. The microbial contamination was found in all tori samples from the harvesting process, presumably due to saliva contamination. Conclusion: Tori bone was different from bone graft substitutes in terms of surface structure, crystallinity, and calcium release. However, tori bone and bone graft substitutes were similar in terms of elemental composition and crystal compounds, which may positively affect their clinical applications. Taken together, our findings suggest that with an effective decontamination, tori bone should be considered as a viable material for bone grafting, as it is not only practical but also cost-efficient for patients.


1997 ◽  
Vol 101 (6) ◽  
pp. 443-447 ◽  
Author(s):  
Z.H. Mai ◽  
H.X. Guo ◽  
W.C. Chen ◽  
G.M. Luo ◽  
Y.R. Wu ◽  
...  

2018 ◽  
pp. 15-21
Author(s):  
J Vasilev ◽  
R Zamogilniy ◽  
D Samokysh

An engineering technique was developed to determine the antifriction efficiency of emulsols during cold rolling according to their physicochemical properties. This method is based on the dimensionless exponent’s kсм, kвяз kэф and kотн.эф, taking into account, respectively, the influence of the chemical and physical properties of emulsols on the antifriction efficiency of the latter and the proposed dependencies for calculating rating of their antifriction efficiency. With the proposed method and criterion kотн.эф antifriction efficiency of 24 different emulsol it was investigated applied in cold rolling and the calculated rating antifriction their effectiveness. It is established that the high antifriction and washing efficiency of modern emulsols is achieved with a value of the kinematic viscosity of the latter at a level of 30-45 mm2/s and an increase in the saponification to 160-195 mg KOH/g.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


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