Presence Of Sodium Lauryl Sulfate Research Articles

An experimental investigation of the effect of the amount of lubricant on tablet properties

Background: Magnesium stearate (MgSt) is widely used as a lubricant in the production of tablets. However, the amount added to a formulation is often too high or it is poorly mixed, which can lead to the production of tablets whose properties are out of specifications. Method: The objective of this work was to investigate by means of a new method based on gamma-ray flux measurement and to study the impact of the amount of MgSt on the mass, thickness, hardness, friability, and disintegration time of tablets containing a 50 : 50 wt.% microcrystalline cellulose and spray-dried lactose pre-blend. Other blends were lubricated with sodium lauryl sulfate (SLS) to compare the performance of the two lubricants in equal amounts. Results: It was observed that, contrary to SLS, a greater amount of MgSt increased the variability of the tablet mass. The tablet hardness decreased with an increasing amount of MgSt, whereas it remained relatively unaffected by the presence of SLS. No solid conclusion could be drawn concerning the relationship between the lubricant concentration and the tablet friability. Conclusion: An amount of 0.25 wt.% MgSt and 0.75 wt.% SLS were found to be sufficient amounts of lubricants to obtain a proper compression.

ChemInform Abstract: One‐Pot Synthesis of 1,2‐Disubstituted Pyrrolo[2,3‐b]quinoxalines via Palladium‐Catalyzed Heteroannulation in Water.

The reaction of N-alkyl-3-chloroquinoxaline-2-amines with 1-alkynes, catalyzed by Pd–Cu, in the presence of sodium lauryl sulfate as the surfactant in water, leads to the one-pot formation of 1,2-disubstituted pyrrolo[2,3-b]quinoxalines in good-to-high yields.

One-pot synthesis of 1,2-disubstituted pyrrolo[2,3-b]quinoxalines via palladium-catalyzed heteroannulation in water

The reaction of N-alkyl-3-chloroquinoxaline-2-amines with 1-alkynes, catalyzed by Pd–Cu, in the presence of sodium lauryl sulfate as the surfactant in water, leads to the one-pot formation of 1,2-disubstituted pyrrolo[2,3-b]quinoxalines in good-to-high yields.

Role of Rhodamine B in photovoltage generation using anionic surfactant in liquid phase photoelectrochemical cell for solar energy conversion and storage

The conversion of solar energy on the basis of photogalvanic effect in liquid phase photogalvanic solar cell is studied experimentally. The photogalvanic effect has been studied in system containing Rhodamine B as a photosensitizer and DTPA as a reducing agent in presence of sodium lauryl sulphate. The photopotential and photocurrent generated by this system were 843.0 mV and 185.0 μA, respectively. The experimental conversion efficiency, fill factor, storage capacity of this cell have also been determined. The effect of different parameters on electrical output of the cell like effect of dye, reductant and surfactant concentration, pH, light intensity, temperature, diffusion length and electrode area were investigated. The absorption properties of newly used dye (Rhodamine B) were analyzed. This photogalvanic cell can be used for 85.0 min in dark. A mechanism of cell photochemical reaction has also been proposed.

Application of non-steroidal anti-inflammatory drugs for palladium determination

AbstractA highly sensitive spectrophotometric method for palladium determination using piroxicam and tenoxicam as new chromogenic reagents has been developed. In the presence of sodium lauryl sulfate (SLS), palladium reacts with piroxicam (PX) or tenoxicam (TX) to form stable yellow orange complexes in an acetate buffer solution of pH 5.0 at 424 nm and 426 nm with molar absorptivity of 7.16 × 104 L mol−1 cm−1 and 1.20 × 105 L mol−1 cm−1, respectively. Sandell sensitivity, detection, and quantitation limits were also calculated. Optimum conditions were evaluated considering pH, reagent concentration, time, temperature, and surfactant concentration. The complex system conforms to Beer’s law over the range of 0.07–1.28 μg mL−1 palladium. The stoichiometric ratio and stability constant were also evaluated. Tolerance limits of many cations and anions were determined. Finally, the proposed method was applied successfully in the determination of palladium in jewellery, anode mud, synthetic mixtures, catalysts, and alloy samples.

Enhancement of photocatalytic degradation of methylene blue in surfactant/ceriurm(III)-titanium dioxide/float pearls aqueous dispersions

Ceriurm(III)-titanium dioxide/float pearls photocatalyst mixed with Sodium Lauryl Sulphate (SLS) were used to degrade methylene blue under visible light illumination. The photocatalyst of Ce3+-TiO2/float pearls was prepared by sol-gel method and characterised by Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), Ultraviolet-visible Diffuse Reflection Spectrum (UV-vis DRS) and Energy Dispersive Spectrometer (EDS). The influence of pH value and dosage of SLS on the photocatalytic activity was studied. The result indicated that the presence of SLS cut down the surface tension of dye liquor, leading to obviously increased degradation rate. The photocatalytic degradation rate reached 93.49% under visible light radiation in 240 min, improved by 10.30% in the non-neutral aqueous.

Nickel-Catalyzed Alkynylation of Aryl Iodides (Sonogashira Reaction) in Water

The Sonogashira coupling of terminal acetylenes with aryl iodides, catalyzed by Ni-Cu, in the presence of sodium lauryl sulfate as the surfactant and cesium carbonate as the base, in water, leads to the formation of aryl alkyne products.

Effect of sodium lauryl sulphate (SLS) on nickel electrowinning from acidic sulphate solutions

The effect of sodium lauryl sulphate (SLS) on the cathodic current efficiency (CE), surface morphology, crystallographic orientations and polarization behaviour of the stainless steel cathode during nickel electrowinning from acidic sulphate solutions was investigated. The results indicated that SLS did not have a significant effect on the cathodic current efficiency. However, noticeable changes in the surface morphology and deposit quality were observed. Cyclic and linear sweep voltammetric studies revealed that an increase in SLS concentration from 2 to 40 mg dm − 3 increased the cathodic potential and shifted the nucleation overpotential (NOP) towards more negative values which was also reflected in the decrease in the rate of electron transfer i.e. i 0 values obtained on both the stainless steel and nickel substrates. The presence of SLS did not change the fcc structure of the electrodeposited nickel but affected the peak intensities of the various crystal planes.

ChemInform Abstract: Pd—Cu‐Mediated Synthesis of 2‐Substituted Imidazo[1,2‐α]pyridines in Water.

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Synthesis of 6-substituted imidazo[2,1- b]thiazoles via Pd/Cu-mediated Sonogashira coupling in water

The reaction of 2-amino-3-(2-propynyl)thiazolium bromide with various iodobenzenes, catalyzed by Pd/Cu, in the presence of sodium lauryl sulfate as surfactant and cesium carbonate as base, in water, leads to the formation of 6-substituted imidazo[2,1- b]thiazoles.

Improving the corrosion and tribocorrosion resistance of Ni–Co nanocrystalline coatings in NaOH solution

Ni–Co nanocystalline coatings were electrodeposited from a modified Watts bath. Increasing the deposition current density had no significant effect on structure, corrosion and tribocorrosion behavior of the coatings. Adding saccharin into the bath reduced the grain size, increased the hardness, changed the texture component from (2 0 0) to (1 1 1), smoothed the surface morphology, increased the corrosion resistance and improved the tribocorrosion behavior of coating. Presence of sodium lauryl sulfate in the bath increased the corrosion resistance of coating by producing a more compact surface morphology. However, the coating showed low tribocorrosion resistance, probably due to its lower hardness.

One-pot Synthesis of 2-Substituted Imidazo[2,1-b][1,3]benzothiazoles via Coupling-Cyclization Under Pd-Cu Catalysis in Water

The reaction of 2-imino-3-(2-propynyl)-1,3-benzothiazole with various aryl iodides, catalyzed by Pd-Cu, in the presence of sodium lauryl sulfate as the surfactant and potassium carbonate as the base, in water, leads to the formation of 2-substituted imidazo[2,1-b][1,3]benzothiazoles. Keywords: Sonogashira coupling, aryl iodide, imidazo[2,1-b][1,3]benzothiazole, Pd-catalyzed, potassium carbonate, sodium lauryl sulfate

Pd-Cu–Mediated Synthesis of 2-Substituted Imidazo[1,2-α]pyridines in Water

The reaction of 2-amino-1-(2-propynyl)pyridinium bromide with various iodobenzenes, catalyzed by Pd-Cu, in the presence of sodium lauryl sulfate as the surfactant and cesium carbonate as the base, in water, leads to the formation of 2-substituted imidazo[1,2-α]pyridines.

Micellization of linear alkyl benzene sulphonate and sodium lauryl sulphate in mixed aqueous solution

The micellization behaviour of linear alkyl benzene sulphonate has been studied conductometrically in presence of sodium lauryl sulphate in aqueous solution. The conductance data are used to obtained values of critical micelle concentration, cmc, of mixed surfactant systems of different compositions. The results are interpreted in the light of various possibilities of micelle formation with equilibriums between possible surfactant species formed by both the surfactant in mixed system. It has been proved by measuring solubilization of anthracene in mixed surfactant systems and effect of temperature on cmc that is the detergency performance of LABS can be enhanced in presence of ½ cmc of sodium lauryl sulphate in aqueous solution.

Simultaneous Determination of Cobalt and Nickel Using Morpholinedithiocarbamate (MDTC) as Reagent by First and Second Derivative Spectrophotometry

AbstractA selective and sensitive derivative method has been proposed for the simultaneous determination of trace amounts of Co(II) and Ni(II) with morpholinedithiocarbamate (MDTC) in the presence of sodium lauryl sulphate (SLS). The molar absorption coefficients of the 1:2 complex of Co(II) and Ni(II) at 326 nm and 322 nm are 2.248 × 104 and 2.505 × 104 L mol−1 cm−1 for zero order. The analytical sensitivity for the second derivative of Co(II) and Ni(II) complexes are 0.0044 μg mL−1 and 0.0060 μg mL−1. The developed derivative procedure, using the zero‐crossing technique, has been successfully applied for the analysis of Co(II) and Ni(II) simultaneously in different alloy samples.

Current efficiency studies of the zinc electrowinning process on aluminum rotating cylinder electrode (RCE) in sulfuric acid medium: Influence of different additives

Abstract This work studies the effect of three additives, sodium lauryl sulfate (SLS), cetyltrimethylammonium bromide (CTABr) and arabic gum (AG) on zinc electrowinning on aluminum in a solution of 85 g L −1 Zn(II) (1.3 M) in 108 g L −1 H 2 SO 4 (1.1 M). The influence of these three additives is analyzed during the different stages of the reduction process using chronopotentiometric techniques on an aluminum rotating disk electrode (RDE). Potential ranges (−1.05 E versus SHE) and current density (−51 i −2 ) within which zinc electrodeposition takes place in the presence of the three different additives were established. These parameters were used to determine current efficiencies ( Φ ), evaluated by electrolysis on an aluminum rotating cylinder electrode (RCE); the zinc deposition efficiency in the presence of SLS, CTABr and AG, was 95%, 96% and 99%, respectively, were all greater than the efficiency obtained without any additive (WA), Φ = 84%. The homogeneity of the deposits at the end of electrolyses implied that the (RCE) promotes uniform current density on the electrode surface and, hence, can be considered a model cell to evaluate current efficiencies.

Osmotic Delivery of Flurbiprofen through Controlled Porosity Asymmetric Membrane Capsule

The release of poorly water-soluble drug, flurbiprofen, through asymmetric membrane capsule of cellulose acetate containing different pore forming agents like glycerol, polyethylene glycol 400, and dibutyl phthalate, in presence of sodium lauryl sulfate was investigated. The asymmetric membrane was fabricated in the shape of capsule body and cap by phase inversion technique. The type of pore forming agent incorporated had a marked influence on the porosity of the asymmetric membrane. However flurbiprofen due to its poor solubility was unable to create enough osmotic pressure and hence less than 10% of drug was released from all the systems with out SLS. However when the study was conducted with SLS, a maximum release of 72% was observed from the capsule with 70% glycerol. The release rates were found to increase with the increase in the concentration of pore forming agent and the amount of SLS encapsulated.

A room temperature process for making Mn 2O 3 nano-particles and γ-MnOOH nano-rods

Nano-size crystals of Mn 2O 3 and MnOOH have been prepared by a simple precipitation process using dilute aqueous solutions of manganese sulphate and ammonia in the presence of sodium lauryl sulphate — a surface active agent. X-ray diffraction spectrometry has been used to identify the phases and to calculate the size of the nano-size crystals using the Scherrer method. The morphology of the crystals has been studied by TEM/HRTEM and Edax has been used to estimate their elemental constituents. The sonication of the prepared nano-size material in acetone leads to the conversion of MnOOH to nano-sized Mn 2O 3.

Kinetics of the acid hydrolysis of isoproturon in the absence and presence of sodium lauryl sulfate micelles

Kinetics of the hydrolysis of isoproturon by hydrochloric acid has been studied spectrophotometrically in the absence and the presence of anionic sodium lauryl sulfate (NaLS) micelles. The anionic micelle was found to increase the rate of reaction. The reaction followed first-order kinetics with respect to isoproturon and was linearly dependent upon [HCl]. In both aqueous and micellar pseudophases, the reaction was started with the protonation of the amino group of isoproturon followed by attack of water to yield phenylcarbamic acid and the corresponding amine, thus obeying the addition–elimination mechanism. The surfactant decreased the activation entropy. The binding constant in consistence with the rate constants was evaluated on the basis of pseudophase ion-exchange model. The added salts (NaCl and KCl) decreased the rate of reaction due to the exclusion of H+ from micellar surfaces.

Synergic influence of a surfactant and ultrasonication on the preparation of soluble, conducting polydiphenylamine/silica‐nanoparticle composites

AbstractConducting polydiphenylamine was used to encapsulate silica nanoparticles through the oxidative polymerization of diphenylamine in the presence of ultrasonic irradiation. The polymerization was performed in the presence of sodium lauryl sulfate as a surfactant. Experiments performed in the absence of ultrasound clearly demonstrated that the application of ultrasonication played multiple roles in the preparation of a composite of polydiphenylamine with silica nanoparticles. Ultrasonication dispersed the silica nanoparticles, converted sodium lauryl sulfate to lauryl alcohol, and augmented the dispersion of the silica‐nanoparticle/polydiphenylamine composite in an organic medium. Silica‐nanoparticle/polydiphenylamine composites were also prepared in the absence of ultrasound and/or sodium lauryl sulfate. The silica‐nanoparticle/polydiphenylamine composites were characterized with Fourier trans form infrared spectroscopy, ultraviolet–visible/near‐infrared spectroscopy, and thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3912–3918, 2006