Action Of Sodium Carbonate Research Articles

In-vivo disintegration and absorption of two fast acting aspirin tablet formulations compared to ibuprofen tablets using pharmacoscintigraphy

IntroductionAspirin is widely used to relieve acute pain and reduce fever and inflammation. New 500 mg and 1000 mg aspirin rapid disintegrating tablets with small active ingredient particle size and sodium carbonate excipient were developed to replace regular 500 mg aspirin tablet formulation containing starch and cellulose. The rapid disintegrating aspirin tablets have been proven to show faster in-vitro dissolution and a shorter time to Cmax (Voelker 2012) resulting in faster pain relief (Cooper 2012). The current study correlates the site and time to complete tablet disintegration with the plasma concentration time profile, using γ-scintigraphy imaging technique. Two 400 mg ibuprofen tablet formulations (ibuprofen acid and ibuprofen lysine salt) have also been analyzed in this study. MethodsOpen label, randomized and four-way crossover trial in 12 healthy fasted males. Scintigraphy images and blood sampling were taken up to 4 h post dose. Tablets were radiolabelled with 4 MBq technetium (99mTc)-labelled DTPA using a drill and fill method (Wilson 2003). Site and time to complete tablet disintegration were derived from the scintigraphy images. Validated bioassays were used to measure plasma concentration. ResultsIn all subjects the aspirin formulations disintegrated rapidly and completely in the stomach (500 mg Aspirin: 9.0 min, 1000 mg Aspirin: 5.0 min). Complete disintegration of the ibuprofen tablets occurred in 5 and 4 out of 12 subjects in the small intestine. Time to complete disintegration was longer (acid: 37.5 min, lysine-salt: 37.5 min) than with the aspirin formulations. This correlates with pharmacokinetics: a substantial difference in Tmax between the two aspirin formulations (500 mg Aspirin: 20 min, 1000 mg Aspirin: 23 min) and the two ibuprofen formulations (acid: 68 min, lysine-salt: 42 min) was observed. ConclusionsThe gastrointestinal disintegration and systemic absorption of the aspirin formulations is faster compared to the ibuprofen formulations.

Harnessing Noncovalent Interactions in Dual-Catalytic Enantioselective Heck-Matsuda Arylation.

The use of more than one catalyst in one-pot reaction conditions has become a rapidly evolving protocol in the development of asymmetric catalysis. The lack of molecular insights on the mechanism and enantioselectivity in dual-catalytic reactions motivated the present study focusing on an important catalytic asymmetric Heck-Matsuda cross-coupling. A comprehensive density functional theory (M06 and B3LYP-D3) investigation of the coupling between a spirocyclic cyclopentene and 4-fluorophenyl diazonium species under a dual-catalytic condition involving Pd2(dba)3 (dba = trans, trans-dibenzylideneacetone) and chiral 2,2'-binaphthyl diamine (BINAM)-derived phosphoric acids (BDPA, 2,2'-binaphthyl diamine-derived phosphoric acids) is presented. Among various mechanistic possibilities examined, the pathway with explicit inclusion of the base (in situ generated sodium bicarbonate/sodium biphosphate) is found to be energetically more preferred over the analogous base-free routes. The chiral phosphate generated by the action of sodium carbonate on BDPA is found to remain associated with the reaction site as a counterion. The initial oxidative addition of Pd(0) to the aryl diazonium bond gives rise to a Pd-aryl intermediate, which then goes through the enantiocontrolling migratory insertion to the cyclic alkene, leading to an arylated cycloalkene intermediate. Insights on how a series of noncovalent interactions, such as C-H···O, C-H···N, C-H···F, C-H···π, lp···π, O-H···π, and C-F···π, in the enantiocontrolling transition state (TS) render the migration of the Pd-aryl to the si prochiral face of the cyclic alkene more preferred over that to the re face are utilized for modulating the enantioselectivity. Aided by molecular insights on the enantiocontrolling transition states, we predicted improved enantioselectivity from 37% to 89% by changes in the N-aryl substituents of the catalyst. Subsequent experiments in our laboratory offered very good agreement with the predicted enantioselectivities.

Thermal decomposition and transformation mechanism of mullite with the action of sodium carbonate

Mullite as one of the major aluminum-containing minerals in pulverized coal fly ash (PCFA) has a stable crystal structure, resulting in the difficulty in aluminum extraction from PCFA. Na2CO3-assisted thermal activation of PCFA is an efficient approach to activate the reactivity of mullite in PCFA. A clear understanding of the decomposition and transformation mechanism of mullite calcined with Na2CO3 is of great significance to clarify the activation mechanism of PCFA and the further process optimization. In this work, the thermal decomposition behavior, the phase transformation and the microstructure change were investigated in detail using thermo-gravimetric and differential scanning calorimetric (TG-DSC), X-ray diffraction (XRD) and magic angle spinning nuclear magnetic resonance (MAS-NMR). The results showed that the phase transformation process was mullite firstly converting into sodium aluminum silicate (SAS, Na1+xAl1+xSi1-xO4, 0 < x < 1) at< 800 °C and then to other minerals with higher structure stability, such as sodium aluminate and sodium silicate, with the increasing of Na2CO3 amount at> 800 °C. The reaction mechanism could be interpreted in terms of the combination change of different oxygen coordination. During the calcination, the Na2O decomposed from Na2CO3 would enter in mullite through filling oxygen vacancies and then react with the oxygen atoms around the AlVI, resulting in the formation of the AlO4 in SAS. Further increase in the calcination temperature and the Na2CO3 amount, the transforming from mullite to SAS would be obviously enhanced. When the temperature was> 800 °C, the residual AlO6 originated from mullite was further transformed into AlO4 with the larger amount of Na2CO3. Meanwhile, the bridging oxygen bonds between AlO4 and SiO4 in SAS were broken by the attacking of Na2O. Subsequently, all the obtained AlO4 and SiO4 as well as Na+ ion could be further recombined in a specific manner to transform into sodium aluminates (AlO4-AlO4), sodium silicates (SiO4-SiO4) and sodium aluminosilicates (AlO4-SiO4).

Management of breast cancer in the elderly. Is treatment changing over time?

Aspirin is widely used to relieve acute pain and reduce fever and inflammation. New 500 mg and 1000 mg aspirin rapid disintegrating tablets with small active ingredient particle size and sodium carbonate excipient were developed to replace regular 500 mg aspirin tablet formulation containing starch and cellulose. The rapid disintegrating aspirin tablets have been proven to show faster in-vitro dissolution and a shorter time to Cmax (Voelker 2012) resulting in faster pain relief (Cooper 2012). The current study correlates the site and time to complete tablet disintegration with the plasma concentration time profile, using γ-scintigraphy imaging technique. Two 400 mg ibuprofen tablet formulations (ibuprofen acid and ibuprofen lysine salt) have also been analyzed in this study.Open label, randomized and four-way crossover trial in 12 healthy fasted males. Scintigraphy images and blood sampling were taken up to 4 h post dose. Tablets were radiolabelled with 4 MBq technetium (99mTc)-labelled DTPA using a drill and fill method (Wilson 2003). Site and time to complete tablet disintegration were derived from the scintigraphy images. Validated bioassays were used to measure plasma concentration.In all subjects the aspirin formulations disintegrated rapidly and completely in the stomach (500 mg Aspirin: 9.0 min, 1000 mg Aspirin: 5.0 min). Complete disintegration of the ibuprofen tablets occurred in 5 and 4 out of 12 subjects in the small intestine. Time to complete disintegration was longer (acid: 37.5 min, lysine-salt: 37.5 min) than with the aspirin formulations. This correlates with pharmacokinetics: a substantial difference in Tmax between the two aspirin formulations (500 mg Aspirin: 20 min, 1000 mg Aspirin: 23 min) and the two ibuprofen formulations (acid: 68 min, lysine-salt: 42 min) was observed.The gastrointestinal disintegration and systemic absorption of the aspirin formulations is faster compared to the ibuprofen formulations.

Scientific Opinion on the safety assessment of the active substances, sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulphate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, for use as active system in food contact materials

This scientific opinion of EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, used in mixture which is packed into sachets for absorbing oxygen/carbon dioxide emitting from/into the headspace surrounding packed food. All substances of this formulation have been evaluated and approved for use as additives in plastic food contact materials or as food additives. No migration of calcium, iron and sodium ions was detected. No volatile organic compounds other than carbon dioxide were detected at the limit of detection of 0.5 μg/l. The CEF Panel concluded that the use of the substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water does not raise a safety concern when used in oxygen absorber/carbon dioxide emitter systems, in sachets that prevent the physical release of their contents into the food. The sachets are to be placed in the headspace of the packaging and as such may come into occasional contact with the food, e.g. during handling. The sachet should not come into direct contact with liquid foods or foods that have and external aqueous liquid phase on the surface (liquid or exudates).

Scientific Opinion on the safety evaluation of the active substances, sodium carbonate peroxyhydrate coated with sodium carbonate and sodium silicate, bentonite, sodium chloride, sodium carbonate for use in active food contact materials

This scientific opinion of the Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety evaluation of the powder mixture of the active substances sodium carbonate peroxyhydrate coated with sodium carbonate and sodium silicate (FCM substance No 1009), bentonite (CAS No 1302–78-9, FCM No 393), sodium chloride (CAS No 7647–14-5, FCM No 985), sodium carbonate (CAS No 497–19-8, FCM No 1008) which are intended to be used as combined oxygen generator and carbon dioxide absorber in packaging containing whole fresh fruits. The powder mixture is placed in a nonwoven polyethylene sachet separated from the food by a pad. In the presence of moisture, sodium carbonate peroxyhydrate first decomposes into sodium carbonate and hydrogen peroxide which decomposes into water and oxygen. Sodium carbonate reacts with carbon dioxide to form sodium bicarbonate. Because the sachet is not placed in direct contact with the food or food exudates, only hydrogen peroxide which decomposes to water and oxygen may be released with no other potential migration of volatile compounds. Based on the conclusion drawn in the EU Risk Assessment Report that hydrogen peroxide is not classified as a mutagen and the results from a subchronic toxicity study with hydrogen peroxide, the Panel concluded that hydrogen peroxide does not raise a safety concern under the intended conditions of use. Therefore the CEF Panel concluded that sodium carbonate peroxyhydrate coated with sodium carbonate and sodium silicate, bentonite, sodium chloride and sodium carbonate do not raise a safety concern for the consumer when used as combined oxygen generator and carbon dioxide absorber, for packaging of whole fruits. The substances should be used in sachets which prevent the release of the powder mixture into the food. Sachets should not be in direct contact with food or food exudates.

The leaching and re-deposition of metal species from and onto conventional supported palladium catalysts in the Heck reaction of iodobenzene and methyl acrylate in N-methylpyrrolidone

When supported palladium catalysts are used for Heck vinylation of iodobenzene with methyl acrylate in N-methylpyrrolidone (NMP) in the presence of triethylamine and sodium carbonate bases, the reaction proceeds homogeneously with dissolved active palladium species that are formed through coordination of NMP and triethylamine with palladium. These active species easily react with iodobenzene (oxidative addition), beginning the catalytic cycle of Heck coupling. The last step of catalyst regeneration takes place with the action of sodium carbonate. The active palladium species are not stable and deposit the metal to support when they cannot find iodobenzene to react in the reaction mixture after this substrate is completely consumed. The re-deposition of palladium occurs on the surfaces of bare support and/or palladium particles remaining on it, depending on the nature of support surface and the number and size of residual metal particles. The growth of palladium particles has been observed after the reuse of catalyst in some case. However, the supported catalysts are recyclable without loss of activity.

Substituted 4(5H)-Oxazolones and Their Salts. 10. Synthesis of 2-[β-(Phenylamino)vinyl]-4(5H)-oxazolones from Their Salts and Z,E-Isomerization at the Double Bond

2-[β-(Phenylamino)vinyl]-5-(1,1-dimethyl-2-acetoxyethyl)-4(5H)-oxazolonium perchlorate was synthesized. The deprotonation ability of this compound in chloroform by the action of sodium carbonate to give 4(5H)-oxazolone, containing enamine fragment at C(2) in the ring was studied. Z,E-Isomerization at the double bond was found at room temperature by the action of the solvents.

Synthesis and biological activity of new heterocyclic compounds 5‐[(1,l‐dimethyl)ethyl]‐3‐aryl‐(1H‐1,2,3‐triazol‐1‐yl)‐5‐isoxazolidinols

AbstractIn this paper new heterocyclic compounds 5‐[(1,1‐dimethyl)ethyl]‐3‐aryl‐(1H‐l,2,3‐triazol‐1‐yl)‐5‐isoxazolodinols were obtained by the reaction of vinyl triazole derivatives with hydroxylamine hydrochloride under the action of sodium carbonate. The biological tests indicate that they had plant‐growth regulating activity.

Effects of the Gas Phase Composition and Genesis of the Active Sodium Carbonate on Its Reactivity Towards Gaseous Mixture SO2 + NOx

The reactivity of the solid active sodium carbonate towards gaseous mixture SO2 + NOx has been measured in the dependence on oxygen and carbon dioxide contents and on genesis of the solid substance. The fixed bed flow reactor working under integral conditions has been used. It was found that the reactivity of the active sodium carbonate of the 1st generation towards gaseous mixture SO2 + NOx is higher than the reactivity of the active sodium carbonate of the 2nd generation. In the temperature range of 130-180 °C the partial pressures of oxygen and carbon dioxide have no decisive influence on the reactivity of the active sodium carbonate of the 1st generation.

Kinetics of the Reaction Between Solid Active Sodium Carbonate of the Second Generation and the Gaseous Sulfur Dioxide

The results are presented of a detailed experimental kinetic study of the heterogeneous reaction between gaseous sulfur dioxide and the solid active sodium carbonate of the second generation which has been prepared by a controlled thermal dehydration of higher hydrates of the sodium carbonate. The measurements have been carried out in an all-glass kinetic apparatus with an integral fixed-bed reactor. The reaction course was studied in dependence on genesis and nature of the active sodium carbonate, on temperature and on composition of the gas phase. The reaction rate is significantly affected by presence of the water vapour which acts as a gaseous catalyst. Experimental data have been treated by using the model proposed by Erdos (Collect. Czech. Chem. Commun. 32, 1653 (1967), and the values of the effective reaction rate constants have been computed. The kinetic study of active sodium carbonate of the second generation has been completed by the determination of microstructure (SEM) of solid samples before and after reaction, and by determining the solid surface composition before and after reaction by means of electronic spectra (ESCA).

Chemical Drying Agents for Alfalfa Hay: Effect on Nutrient Digestibility and Lactational Performance

Effects of chemical drying agents for hay on plasma profile, lactational performance, and nutrient digestibility by cows were studied. First-cutting alfalfa (late bud) was harvested as hay and treated when cut by applying untreated control, a commercial drying agent (7.64kg/ha), or a mixture of active ingredients, potassium carbonate and sodium carbonate (7.47kg/ha). Six multiparous Holstein cows (120 to 150 d postpartum) were fed diets (two cows per treatment) containing 55% hay and 45% concentrate (DM basis) in a balanced two period changeover design. Plasma profiles were similar for all cows, regardless of hay treatment. There were no differences in milk yield, milk fat, or milk protein percentages for control, drying agent, or mixture. Intake of DM was not different among treatments. Apparent digestibilities of DM, OM, CP, NDF, and ADF were not different among treatments. Treatment of alfalfa hay with chemical drying agents did not alter plasma profile, milk production, or nutrient digestibility in midlactation cows.

ChemInform Abstract: Analogues of the Active and Inactive Sodium Carbonate.

AbstractDie Reaktivität der wasserfreien Alkalimetallcarbonate M2CO3 (M: Li, Na, K, Rb, Cs) gegenüber SO2 wird experimentell in Abhängigkeit von der Natur des Kations und vom Darstellungsweg des Carbonats (durch thermische Zers. des Hydrogencarbonats oder thermische Dehydratisierung von Carbonathydraten) untersucht.

Effect of Sodium Carbonate on the Hydration of Tricalcium Silicate

The effect of sodium carbonate (2%) on the hydration of tricalcium silicate was studied. Free lime, nonevaporable water content, calorimetric measurements, analysis of the liquid phase for Ca2+ and OH− ions, zeta potential measurements, and compressive strength measurements were made. The accelerating action of sodium carbonate can be interpreted in terms of adsorption of ions. Further, since sodium carbonate is a structure breaker for water, more free water will be available in the presence of sodium carbonate, which may accelerate the reaction.

Reactivity of the solid sodium carbonate towards the gaseous hydrogen chloride and the sulphur dioxide

The rate of reaction of the anhydrous sodium carbonate with the hydrogen chloride and its mixture with sulphur dioxide was measured in an integral fixed-bed reactor. Reactivity of the active sodium carbonate towards the hydrogen chloride is lower as compared with its reactivity towards the sulphur dioxide. A relationship was found between the reactivity of the solid and the way of its preparation. The inactive form of the sodium carbonate is inactive towards both the sulphur dioxide and the hydrogen chloride. The active form of the sodium carbonate exhibits towards the hydrogen chloride a reactivity which is by orders of magnitude higher than that of the inactive form. The variation of the ratio of partial pressures of the hydrogen chloride and the sulphur dioxide in the reaction with the sodium carbonate does not affect significantly the total degree of the solid conversion, which attained a value of 65% in laboratory experiments. The degree of gas purification from the acid components did not fall under a value of 99% up to a solid conversion of about 50% at a mean gas contact time of about 10-2 s.

Analogues of the active and inactive sodium carbonate

The reactivity of the anhydrous carbonates of alkaline metals with sulphur dioxide has been studied experimentally in dependence both on the nature of the cation and on the way of preparation of the anhydrous carbonate. The carbonates were prepared either by thermal decomposition of hydrogen carbonates or by thermal dehydration of carbonate hydrates. The carbonates of lithium, sodium, potassium, rubidium and caesium have been investigated. Kinetic measurements were carried out in a flow reactor in the integral regime at 423 K under atmospheric pressure, with a gas containing 0.2 vol.% of sulphur dioxide and 2.0 vol.% of water vapour in the nitrogen as a carrier gas. The reactivities have been compared on the basis of time dependence of the conversion of carbonate to sulphite.

Mass transfer between a moving gas stream and single particles of some important sorbents for sulphur dioxide

For the particles of calcium oxide and active sodium carbonate an effect of mass transfer is explored on the overall rate of their reactions with sulphur dioxide. The results of a simple analysis show that the mass transfer resistance in the gas phase cannot be neglected. The extraordinary reactivity of active sodium carbonate can be fully utilized only in such contactors where very high rates of mass transfer are ensured.

The effect of parent substance genesis on the reactivity of active sodium carbonate towards sulphur dioxide

The reactivity of sodium carbonate towards sulphur dioxide was studied in dependence on the effect of genesis of sodium hydrocarbonate as the parent substance of the reacting solid. The reactivity expressed by means of the effective rate constant differed approximately one half of order of magnitude among five various samples. A qualitative correlation has been found between the bulk density of the parent substance and the reactivity of active sodium carbonate prepared thereof. Experimental evidence is given that the effect of genesis of the parent substance is not decisive for the reactivity of the active sodium carbonate towards sulphur dioxide. Henceforth, as the decisive factor for the reactivity of the sodium carbonate the way of its preparation from the parent substance must be considered.

Application of the reaction kinetics and dispersion model to gas-solid reactors for removal of sulfur dioxide from flue gas

The conversions of a reactive, micro-grained limestone were studied in terms of exposure time and concentration of sulfur dioxide in the flue gas. The rates of the sulfation reaction were correlated as a function of the conversion of calcium oxide to sulfate and concentration of sulfur dioxide in the gas phase. In comparison with active sodium carbonate the sulfation of limestone particles proceeds at the rate which is substantially lower than the sulfation rate of soda particles. The empirical kinetic equation developed in this study is further applied in a two-phase dispersion model of simplified non-ideal flow behavior of the gas and solid in the reactor. The model can serve a rational basis for the conceptual design of a suitable contacting apparatus. Numerical solutions of the model equations outline possibilities and limitations of the dry lime process for the removal of sulfur dioxide from hot flue gas.

The effect of particle size on the reactivity of active sodium carbonate towards sulfur dioxide

The effect of particle size (0.33-1.0 mm) of the sodium carbonate on the reactivity of the active sodium carbonate prepared therefrom towards the sulfur dioxide was studied in a fixedbed integral reactor at a temperature of 150 °C. The found dependence of the reaction rate on the particle size exhibits an unexpected course; at sizes of about 0.65 mm, a distinct minimum appears. The reaction rate decreases approximately ten times in the first branch of this dependence. The controlling factor of the reactivity of sodium carbonate, however, remains to be the method of preparing the active form.