We have developed a synthesis method of rhombic dodecahedral Pd@Pt core-shell nanocrystals bound exclusively by {110} facets with controlled numbers of Pt atomic layers to study the surface strain-catalytic activity relationship of Pt{110} facets. Through control over growth kinetics, the epitaxial and conformal overgrowth of Pt shells on the {110} facets of rhombic dodecahedral Pd nanocrystals could be achieved. Notably, the electrocatalytic activity of the Pd@Pt nanocrystals toward oxygen reduction reaction decreased as their Pt shells became thinner and thus more in-plane compressive surface strain was applied, which is in sharp contrast to previous reports on Pt-based catalysts.
View Article and Find Full Text PDFIonic liquids (ILs) have gained much attention as alternative solvents to volatile organic solvents due to their attractive properties. This study aimed to develop an efficient method for the selective separation of decursin (D) and decursinol angelate (DA) from Nakai () using ILs and crystallization. The IL 1-butyl-3-methylimidazolium tetrafluoroborate ((BMIm)BF) was the most efficient at extracting D and DA.
View Article and Find Full Text PDFResearch studies related to the polymorphs of l-Carnitine orotate (CO), a medication used for the treatment and prevention of liver diseases, are insignificant or almost nonexistent. Accordingly, in the present study, l-Carnitine orotate (CO) was prepared for investigating CO polymorphs. Here, a reactive crystallization was induced by reacting 1g of l-Carn (1 equivalent) and 0.
View Article and Find Full Text PDFIn the present study, the screening of Mirabegron (MBR) co-amorphous was performed to produce water-soluble and thermodynamically stable MBR co-amorphous with the purpose of overcoming the water solubility problem of MBR. MBR is Biopharmaceutics Classification System (BCS) class II drug used for the treatment of an overreactive bladder. The co-amorphous screening was carried out by means of the vacuum evaporation crystallization technique in methanol solvent using three water-soluble carboxylic acids, characterized by a pKa difference greater than 3 with MBR such as fumaric acid (FA), l-pyroglutamic acid (PG), and citric acid (CA).
View Article and Find Full Text PDFTenofovir disoproxil (TD), an anti-virus drug, is currently marketed under its most stable form, Form-I of Tenofovir disoproxil fumarate (TDF). However, studies regarding the properties of TD free base crystal as a promising drug as well as its crystal structure have not yet been reported. This assumption was made because TD free base is not directly produced in a solid form during the manufacturing process.
View Article and Find Full Text PDFIonic liquids (ILs) are defined as salts with a melting point below 100 °C. ILs have received increasing attention as new alternative to organic solvents because of their unique physicochemical properties. Therefore, this study was conducted in the purpose to present the efficacy of ILs as new solvents capable to control the Polymorphic transformation phenomenon.
View Article and Find Full Text PDFTo search polymorphs of adefovir dipivoxil (AD), the polymorphic transformation approach in solution was developed. Also, the kinetics of polymorphic transformation was investigated to effectively control polymorphs. The AD crystals were obtained by crystallization at -10°C, and then the polymorphic transformation was induced by raising temperature.
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