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Showing 1 to 20 of 20 for “"Salt formation"”.
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A kinetic template effect in arylphosphonium salt formation.
… of a "kinetic template effect" which assists the formation of arylphosphonium salts from aryl halides and tertiary phosphines in the presence of a transition metal halide catalyst in refluxing ethanol. The "kinetic template effect" arises from the presence in the aryl halide of a limited range of …
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Crystalline Salt Formation of an Acidic Drug Indomethacin Using Hot Melt Extrusion Technology
Although salt formation is the most ubiquitous and effective method of increasing the solubility and dissolution rates of acidic and basic drugs, it consumes large quantities of organic solvents and is a batch process. Herein, we show that the dissolution rate of indomethacin (a poorly …
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A Dual Approach of Salt Formation and Amorphous Solid Dispersion for Improved Oral Drug Delivery
… approach to solve this issue by combining salt formation and amorphous solid dispersion. Three weakly basic belonging to BCS class II drugs, clofazimine, aripiprazole, and haloperidol, were selected as model drugs. Ten salts of each drug were prepared with counterions with ΔpKa> 3 using a …
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Improving the solubility and dissolution of poorly soluble drugs by salt formation and the consequent effect on mechanical properties
… poor aqueous solubility and should readily form salts. The counterions used for salt formation were: butylamine, pentylamine, hexylamine, octylamine, benzylamine, cyclohexylamine, tert-butylamine, 2-amino-2-methylpropan2-ol, 2-amino-2-methyl propan-1,3-ol and tromethamine. Solubility was …
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New routes to enantioenriched substances through small organic molecules
… the results obtained from the diastereoisomeric salt formation (n salt, p salt and p1,n1 salt) between non-racemic trans-chrysanthemic acid (trans-ChA) and pure enantiomers of threo-2-dimethylamino-1-phenyl-1,3-propanediol (DMPP). The occurrence of p1,n1 salt formation can have profound effects …
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Polymorphs, cyclodextrin inclusion complexes and salts of the bronchodilator tulobuterol
… polymorphs, cyclodextrin inclusion complexes and salts of tulobuterol, a drug with bronchodilating properties. Polymorphic drugs are of interest to the pharmaceutical industry because of their varied physical properties, whilst the increase in aqueous solubilities of drugs by their inclusion …
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ACID-BASE REACTIONS IN DIFFERENT SOLID-STATE FORMS
… in pharmaceutical systems with samples including salts, amorphous solid dispersions, and in formulated products. Salt formation of active pharmaceutical ingredients (APIs) is widely recognized as one of the most commonly used approaches to modify the solubility and dissolution rate. Formulating …
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Fabrication, assembly, and electrical characterisation of gold nanowire
… wettability, hydrogen bonding, carboxylate salt formation, electrostatic interactions between charged surfactants, and biotin binding. Of particular interest is the ability to control both the placement and orientation of nanowires onto surfaces. These conditions have been best satisfied by …
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A structural database for pharmaceutical salt selection
Salt formation is an important technique used in preclinical pharmaceutical development to modulate and optimise the physicochemical properties of a drug molecule containing an ionisable functional group. The current approach to salt selection relies on semi-empirical screening of the …
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Synthesis and properties of some 2,5-dihydrothiophene 1,1-dioxides
… Diels- Alder reaction, pyrolysis and salt formation. 4. A synthesis of conjugated, substituted dienes was illustrated by the synthesis of 2-bromomethyl- 1,3-butadiene. 5. A novel Diels-Alder reaction between 3-bromomethyl and 2,5-dihydrothiophene 1, 1-dioxide has been described. 6. The …
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Synthesis and Characterization of Wholly Aromatic, Water-Soluble Polyimides and Poly(amic acid)s Towards Fire Suppression Foams
… use of sulfonated monomers and poly(amic acid) salt formation enables tunable structures and water solubilities. The polymers maintain competitive thermal stabilities to conventional polyimides and, when combined with readily available, non-toxic surfactants (SDS), produce stable foams. The …
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Interactions between solutes in displacement solutions and oil bearing rocks.
… the effect of clay contact with sea water and/or formation water. To try and understand the surfactant solution more fully an attempt was made to determine the number of bound Ca2+ ions and A13+ ions using an ion-selective electrode and atomic adsorption spectroscopy techniques. The results of the …
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Crystal engineering approaches to solid-state pharmaceutical systems
… solid-state and actively manipulating it, via salt formation, co-crystal synthesis or inclusion complexation, for example. Presented in this work are three distinct approaches to the control and development of solid-state form of organic molecules and pharmaceuticals. The first of these …
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Asymmetric induction in solid state photochemistry
… to crystallize as chiral crystals by forming salts with chiral counterions. Photolysis of the chiral crystals resulted in asymmetric induction in the products. The regioselectivity of the photorearrangements of the starting materials prior to salt formation was studied in solution as well as …
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Investigation of Enhancement of Furosemide Solubilization with Cyclodextrins and a Novel Octenyl Succinate Anhydride Starch
… systems, nanosuspension, use of surfactants, salt formation, cyclodextrin complexes and solid dispersion etc.</p> <p>Chapter 1 is an introduction into biopharmaceutics classification system (BCS) and novel drug solubilization techniques. It provides a brief history of the BCS and its …
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Enhanced Etoposide Solubility and Anticancer Activity using Complexation and Nanotechnology
… with three specific aims: (i) co-amorphous salt formation with drug complexation by L-Arginine (ARG), (ii) solid dispersion of V-P16 (C-VP-16) in Sodium Acetate (SA) crystal, and (iii) nanomicellar formulation (NMF) using D -α-Tocopherol polyethylene glycol 1000 succinate (Vitamin E TPGS ) …
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An Assessment of Community-Scale Electrodialysis Desalination Systems and Improved Scale Mitigation through Pulsed Operation
… electrodialysis systems is limited by scale formation, defined as the attachment of inorganic compounds to membrane surfaces. In an electrodialysis system, selective transport of ions through membranes results in the formation of concentration polarization (CP) near membrane surfaces which …
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Development of Micro to Milli-Scale Multiphase Reactors with and Without Solids for Integration Into Mini-Monoplants
… having difficulties associated to gas and salt formation. In the first reaction, an oscillatory energy dissipation rate of 13 W/kg was effective in continuously keeping solids suspended at concentrations of 7.9 wt% and 5.8 wt% for 2 hours and 5 hours, respectively, whereas gas generation in …
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Electron beam lithography of molecular glass resist films prepared by physical vapor deposition
The progress of our information society in this current era depends mostly on the improvement of the computing speed of microprocessors. Therefore semiconductor industries realize further developments in processor architecture but also in the patterning process which is utilized for the …
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Characterisation of drug loaded insoluble polymeric matrices prepared by hot melt extrusion technology for drug delivery applications.
… solid state plasticizers. Two additional quinine salts were manufactured using acid base reactions forming quinine benzoate and quinine salicylate. Through the use of these additional salt forms, salt counter ion was confirmed to impart a significant influence on the solubility of drug within the …