- Round Granules of Dimethyl Fumarate by Three-in-One Intensified Process of Reaction, Crystallization, and Spherical Agglomeration in a Common Stirred Tank
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Pure, isomorphic, round, and free-flowing dimethyl fumarate granules in a size range of 250-2000 μm were successfully produced directly from esterification through the three-in-one intensified process of three distinctive steps of reaction, crystallization, and spherical agglomeration (SA) in a 0.5 L sized jacketed glass stirred tank. Dimethyl fumarate was prepared by sulfuric acid catalyzed esterification of fumaric acid with methanol. The reaction temperature was below the maximum allowable limit of 65 °C as determined by reaction kinetics to avoid the runaway situation. The dissolution rate of primary crystals of dimethyl fumarate was inversely proportional to the particle size which was strongly affected by the antisolvent addition and temperature cooling schemes during crystallization. However, the dissolution rate of the round granules was mainly dependent on the exterior dimension of the granules and not so much on the primary crystal size inside the granules. The mechanical properties such as density, porosity Carr's index, friability, and fracture force of round dimethyl fumarate granules generated in (1) three-in-one processes with the final temperatures at either 5 or 25 °C (Three-in-one I and II) and (2) SA of dimethyl fumarate, which was done separately and disconnected from the train of reaction and crystallization process at either 5 or 25 °C (SA I and II), were thoroughly studied and compared. The concept of scale-up for Three-in-one I and II was also verified in a 10 L sized jacketed glass stirred tank. Powder manufacturability such as flowability, blend uniformity, and compressibility had been substantially enhanced by spherical agglomeration. The added values of free-flowing and easy-to-pack properties to dimethyl fumarate in addition to its original intrinsic slip planes in the crystal lattice would make direct compaction into tablets feasible.
- Chen, Chih Wei,Lee, Tu
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- Construction of diverse supramolecular assemblies of dimetal subunits differing in coordinated water molecules via strong hydrogen bonding interactions: Synthesis, crystal structures and spectroscopic properties
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Three new supramolecular assemblies (constructed through strong hydrogen bonding) of [ Cu2(bpta)2(fum)(H2O)2](ClO4)2 (2) and [Cu2(bpta)2(tdc)(H2O) (ClO4)](ClO4).3H2O (3), which are synthesised by one pot self-assembly of the metal salt, bpta ligand and the corresponding dicarboxylate under the same reaction conditions, are reported (where adc = acetylene dicarboxylate, fum = fumarate, tdc = 2,5-thiophenedicarboxylate and bpta =N,-Rfnet′-bis(2-pyridylmethyl)-tert-butylamine). These compounds have varying degrees of coordinated water molecules per dimetal subunits (four for 1, two for 2 and one for 3, respectively). Furthermore, the orientation of the coordinated water molecules in 1 and 2, with respect to the mono (carboxylato)-bridged dimetal subunit, is different (cis and trans, respectively). On the other hand, there is a coordinated perchlorate ion in 3 making the two metal centers inequivalent. Unlike 1 and 3, there are no lattice water molecules in 2. This difference in the dimetal subunit in 1-3 and the presence or absence of the lattice water molecules are the keys to forming the diverse supramolecular assemblies. In 1 and 3, the involvement of lattice water molecules in the construction of such assemblies is distinctly different. In case of 2, the formation of supramolecular assembly depends on the coordinated water molecule (trans to each other) and thus a ladder shaped supramolecular assembly is the result. The strength of hydrogen bonding observed in the networks of 1-3 is indicated in the O· · ·O distances (2.596 ? to 3.160 ?) and the O-H.O angles 124° to 176°. All are characterised by elemental analysis, FTIR spectroscopy and single crystal X-ray diffraction studies. [Figure not available: see fulltext.]
- Khullar, Sadhika,Mandal, Sanjay K.
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- 2, 3-Butanediamide Epoxide Compound and Preparation Method and Use Thereof
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Provided are a compound of formula I which can be used as a drug against small RNA virus infections, and optical isomers, pharmaceutically acceptable salts, solvates or hydrates thereof. Also provided are the preparation method of the compound, the method for using the compound for treating bacterial infections and the use of the compound in the preparation of a drug for preventing and/or treating viral diseases caused by small RNA viruses.
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Paragraph 0157
(2016/05/19)
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- METHODS FOR FORMING SILVER-NANOPARTICLE TREATED SURFACES
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Disclosed is method of making metal nanoparticles comprising, a) adding in no particular order, an aqueous solution of a stabilizing agent solution, an anionic donating solution and a soluble metal salt solution, and b) adding a reducing solution. Also disclosed are metal nanoparticles made by the method.
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Page/Page column
(2015/01/18)
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- Study of corrosion and scale inhibition of polyepoxysuccinic acid derivative
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Polyepoxysuccinic acid derivative was synthesized from L-cysteine and polyepoxysuccinic acid a condensation polymer formed by cyclization and polymerization with maleic anhydride. The structure of polyepoxysuccinic acid derivative was characterized by means of FTIR and 13C NMR. The scale inhibition and corrosion inhibition performances of polyepoxysuccinic acid derivative were studied. Scale inhibition and corrosion mechanisms were analyzed by means of SEM. The scale inhibition rate of polyepoxysuccinic acid derivative can reach 98.9 % under Ca2+ 400 mg L-1, HCO3- 800 mg L-1, polyepoxysuccinic acid derivative 8 mg L-1. Polyepoxysuccinic acid derivative is better than polyepoxysuccinic acid in corrosion inhibition performance and the corrosion inhibition rate can reach 65.14 % at 40 °C in dynamic experiment. SEM showed that the calcium carbonate crystal lattice was distorted completely from calcite to vaterite by using polyepoxysuccinic acid derivative. The surface of the test piece has dense protective adsorption film layer when it was immersed in solution with polyepoxysuccinic acid derivative.
- Liu, Xinhua,Wang, Wenjing,Tong, Xinjia,Ding, Yunfei,Zhao, Xinqiang,Su, Hong
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p. 7716 - 7720
(2015/02/02)
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- ANTIMICROBIAL SILVER COMPOSITIONS
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The present invention comprises methods and compositions for antimicrobial silver compositions comprising silver nanoparticles. The present invention further comprises compositions for preparing silver nanoparticles comprising at least one stabilizing agent, one or more silver compounds, at least one reducing agent and a solvent. In one aspect, the stabilizing agent comprises a surfactant or a polymer. The polymer may comprise polymers such as polyacrylamides, polyurethanes, and polyamides. In one aspect, the silver compound comprises a salt comprising a silver cation and an anion. The anion may comprise saccharinate derivatives, long chain fatty acids, and alkyl dicarboxylates. The methods of the present invention comprise treating devices with the silver nanoparticle compositions, including, but not limited to, such devices as woven wound care materials, catheters, patient care devices, and collagen matrices. The present invention further comprises treatment of humans and animals wacr6ith the antimicrobial devices described herein.
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Page/Page column 69
(2010/10/20)
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- Hydrogenation and Isomerization of Disodium Maleate in the Solid Phase over Fine Nickel Powder
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Disodium maleate was converted to a mixture of disodium maleate, fumarate, and succinate in the solid phase when particles of the starting material were kept in contact with fine nickel powder pretreated with hydrogen gas at 200 deg C.
- Harada, Tadao,Osawa, Tsutomu
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p. 1168 - 1169
(2007/10/02)
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- Chemical process
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There is disclosed herein improved processes for the preparation of ether carboxylates by reacting in an alkaline reaction medium the salts of maleic acid and a carboxylic or polycarboxylic acid having a reactive hydroxyl group on a non-carbonyl carbon atom in the presence of a calcium ion catalyst wherein unreacted acid salts are recovered from the reaction medium by lowering the pH of the reaction medium to a range of from about 4 to about 6. The precipitated salts are recycled to the synthesis reaction to prepare additional amounts of product.
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