Sodium Cetyl Sulfate Research Articles

Interaction of cyclodextrins with 1,3-di(1-naphthyl)propane and the additive effects of ionic surfactants

The interaction between cyclodextrins (CDs) and 1,3-di(1-naphthyl)propane (1) in aqueous methanol (V:V=1:1) has been investigated by means of fluorescence emission and UV absorption. Fluorescence enhancement and absorption spectra reveal that β- or γ-CD can form inclusion complexes with 1, but a-CD cannot. One of these complexes is identified as ground state complex (2:1), i.e. the eclipsed conformer of 1 is included. Molecule 1 can be driven out of the CD cavity by sodium dodecylsulfate (SDS) molecule, but cannot by cetyltrimethylammonium bromide (CTAB) or sodium cetylsulfate (SCS) molecules due to their alkyl chain coiling.

Final Report on the Safety Assessment of Sodium Cetearyl Sulfate and Related Alkyl Sulfates as Used in Cosmetics

Sodium cetearyl sulfate is the sodium salt of a mixture of cetyl and stearyl sulfate. The other ingredients in this safety assessment are also alkyl salts, including ammonium coco-sulfate, ammonium myristyl sulfate, magnesium coco-sulfate, sodium cetyl sulfate, sodium coco/hydrogenated tallow sulfate, sodium coco-sulfate, sodium decyl sulfate, sodium ethylhexyl sulfate, sodium myristyl sulfate, sodium oleyl sulfate, sodium stearyl sulfate, sodium tallow sulfate, sodium tridecyl sulfate, and zinc coco-sulfate. These ingredients are surfactants used at concentrations from 0.1% to 29%, primarily in soaps and shampoos. Many of these ingredients are not in current use. The Cosmetic Ingredient Review (CIR) Expert Panel previously completed a safety assessment of sodium and ammonium lauryl sulfate. The data available for sodium lauryl sulfate and ammonium lauryl sulfate provide sufficient basis for concluding that sodium cetearyl sulfate and related alkyl sulfates are safe in the practices of use and concentration described in the safety assessment.

The Effect of Synergism Behavior in Binary Mixtures of Some Surfactants with Ethyl Xanthat Absorbed on Clay for Wastewater Treatment

Surface tension, sedimentation, and turbidity experiments were conducted in order to study the synergism behavior of some surfactants with ethyl xanthat mixtures on the reduction of surface tension of their aqueous solutions and on the hydrophilicity of clay surface for using it as absorbent to oil in wastewater treatment. The following systems were studied: 1) potassium ethyl xanthat (KEX) with sodium cetyl sulphate (SCS); 2) potassium ethyl xanthat with cetyl trimethyl ammonium bromide (CTAB); and 3) potassium ethyl xanthat with ethoxylated palmetic acid (EPA). A synergistic effect of the combined reagents was found to enhance the hydrophilicity of clay and also to reduce the surface tension depending mainly on the surface properties of the mixtures.

DNA encapsulation by biocompatible catanionic vesicles

The encapsulation of DNA by catanionic vesicles has been investigated; the vesicles are composed of one cationic surfactant, in excess, and one anionic. Since cationic systems are often toxic, we introduced a novel divalent cationic amino-acid-based amphiphile, which may enhance transfection and appears to be nontoxic, in our catanionic vesicle mixtures. The cationic amphiphile is arginine– N-lauroyl amide dihydrochloride (ALA), while the anionic one is sodium cetylsulfate (SCS). Vesicles formed spontaneously in aqueous mixtures of the two surfactants and were characterized with respect to internal structure and size by cryogenic transmission electron microscopy (cryo-TEM); the vesicles are markedly polydisperse. The results are compared with a study of an analogous system based on a short-chained anionic surfactant, sodium octylsulfate (SOS). Addition of DNA to catanionic vesicles resulted in associative phase separation at very low DNA concentrations; there is a separation into a precipitate and a supernatant solution; the latter is first bluish but becomes clearer as more DNA is added. From studies using cryo-TEM and small angle X-ray scattering (SAXS) it is demonstrated that there is a lamellar structure with DNA arranged between the amphiphile bilayers. Comparing the SOS containing DNA–vesicle complexes with the SCS ones, an increase in the repeat distance is perceived for SCS. Regarding the phase-separating DNA–amphiphile particles, cryo-TEM demonstrates a large and nonmonotonic variation of particle size as the DNA–amphiphile ratio is varied, with the largest particles obtained in the vicinity of overall charge neutrality. No major differences in phase behavior were noticed for the systems here presented as compared with those based on classical cationic surfactants. However, the prospect of using these systems in real biological applications offers a great advantage.

Spontaneous Formation of Vesicles and Dispersed Cubic and Hexagonal Particles in Amino Acid-Based Catanionic Surfactant Systems

Mixed catanionic surfactant systems based on amino acids were investigated with respect to the formation of liquid crystal dispersions and the stability of the dispersions. The surfactants used were arginine-N-lauroyl amide dihydrochloride (ALA) and N(alpha)-lauroyl-arginine-methyl ester hydrochloride (LAM), which are arginine-based cationic surfactants; sodium hydrogenated tallow glutamate (HS), a glutamic-based anionic surfactant; and the anionic surfactants sodium octyl sulfate (SOS) and sodium cetyl sulfate (SCS). It is demonstrated that in certain ranges of composition there is a spontaneous formation of vesicular, cubic, and hexagonal structures. The solutions were characterized with respect to internal structure and size by cryogenic transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), and turbidity measurements. Vesicles formed spontaneously and were found for all systems studied; their size distribution is presented for the systems ALA/SCS/W and ALA/SOS/W; they are all markedly polydisperse. The aging process for the system ALA/SOS/W was monitored both by turbidity and by cryo-TEM imaging; the size distribution profile for the system becomes narrower and the number average radius decreases with time. The presence of dispersed particles with internal cubic structure (cubosomes) and internal hexagonal structure (hexosomes) was documented for the systems containing ALA and HS. The particles formed spontaneously and remained stably dispersed in solution; no stabilizer was required. (Cubosome and hexosome are USPTO registered trademarks of Camurus AB, Sweden.) The spontaneous formation of particles and their stability, together with favorable biological responses, suggests a number of applications.

Characterization and quantitation of apolipoprotein B-100 by capillary electrophoresis

The interaction of low density lipoproteins (LDL) with different surfactants was studied by capillary electrophoresis (CE) and sucrose density gradient ultracentrifugation as part of developing a method for quantitation of apoB-100 in serum. A mixture of surfactants consisting of 70% sodium dodecyl sulfate (SDS), 25% sodium myristyl sulfate, and 5% sodium cetyl sulfate was found to delipidate LDL particles more effectively than pure SDS or sodium decyl sulfate. The delipidation products of LDL [apolipoprotein B-100 (apoB-100) and lipids] were resolved as two distinct peaks by CE when using a 3.5 mm 70% SDS mixture, 20% (v/v) acetonitrile, 50 mm sodium borate, pH 9.1 buffer. This CE method was also used to characterize apoB-100 derived from samples of lipoprotein [a] and very low density lipoproteins (VLDL). A CE-based quantitation method for apoB-100 was developed utilizing the observed linear relationship between apoB-100 concentration and its corrected 214 nm absorbance peak area measured on-line by CE. Concentration values of apoB-100 in LDL and VLDL samples were determined by CE and found to be accurate when compared to values obtained by immunoturbidimetric analysis and the Lowry method. Capillary electrophoresis can be used as a precise, accurate, and specific on-line method for the qualitative and quantitative analysis of the apoB-100 component of VLDL and LDL-related lipoproteins.—Cruzado, I. D., S. L. Cockrill, C. J. McNeal, and R. D. Macfarlane. Characterization and quantitation of apolipoprotein B-100 by capillary electrophoresis. J. Lipid Res. 1998. 39: 205–217.

The Effect of Surfactants on the Rate of Decarboxylation of p-Aminosalicylic Acid in Acidic Aqueous Solutions

p-Aminosalicylic acid, which exists in four ionic forms and whose decarboxylation is well known, was used as a model drug to investigate the effects of surfactants with different charges on its stability. The greatest reduction in the rate of decarboxylation at 50°C occurred when the charge on the micelles was opposite to that of the charge on the drug or when both the drug and the micelle had a neutral charge. Thus, at the highest surfactant concentration, 3 or 5% (w/v), there was a 59% reduction in the rate at pH 2.68 in the presence of the nonionic surfactant polyoxyethylene 24 monocetyl ether, 69% reduction in the rate at pH 4.88 in the presence of the cationic surfactant hexadecyl trimethylammonium bromide, and a 43% reduction at pH 1.01 in the presence of the anionic surfactant sodium cetyl sulfate. The decrease in the rate of decarboxylation was attributed to the partitioning of the drug into the micelles, which provided a phase for improved stabilization. Partition coefficients and rate constants for decarboxylation of the drug inside the micelles were calculated.

The effect of electrolytes on the cloud point of mixed solutions of polypropylene glycol and ionic surfactants

The cloud points of polypropylene glycol (PPG) in the presence of small amounts of ionic surfactants, including dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and sodium cetyl sulfate (SCS) have been determined. The results show that the cloud point of PPG will be elevated if a certain amount of ionic surfactant is added. The longer the hydrocarbon chain length of the ionic surfactant homologues, the stronger the effect is, and the effect of anionic surfactants is stronger than that of cationic surfactants with the same hydrocarbon chain length. On the other hand, the cloud point remains unaltered on addition of the same amount of inorganic salt. However, when salts are added to the PPG solution in the presence of a certain amount of ionic surfactants, the cloud point decreases in a ratio depending on the concentration of salts, the nature of the ions and, particularly, the valency of the ions with charges opposite in sign to the charges of the surface-active ion. For systems of 0.01% PPG + SCS and 0.1% PPG + SCS, the valency of the cation of salts is decisive, and the order of the effect is: 1/3 LaCl 3 > 1/2 CaCl 2, > NaCl. For the system of 0.1% PPG + CTAB, the valency of the anion of electrolytes plays the dominant role, and the order of the depressing effect is: 1/3 K 3Fe(CN) 6 > 1/2 Na 2SO 4 > NaBr. For the system of 0.01% PPG + CTAB, a striking phenomenon was observed, i.e. the cloud point was enhanced rather than decreased by the addition of electrolytes. An explanation in terms of the enhancing adsorption of surface-active ions on the PPG chains due to the addition of electrolytes was suggested.

Penetration of sodium cetylsulfate into monolayers of 1,2-dipalmitoyl- and 1,2-dimyristoyl-phosphatidylethanolamine

The penetration of sodium cetylsulfate into monolayers of dipalmitoyl- and dimyristoyl-phosphatidylethanolamine was studied by the measurement of surface and penetration pressures using the vertical plate method of Wilhelmy. The penetration isotherms in two systems were investigated at different initial molecular areasAM:

The Photoreduction of Thionine and Surfactant Thionine by Iron(II) in Anionic Micelles and Microemulsions

AbstractThe rate constants for the iron(II)‐thionine and surfactant thionine system have been determined in aqueous solution, sodium dodecyl sulfate (SDS) micelles, and in a mineral oil‐in‐water microemulsion stabilized by sodium cetyl sulfate (SCS) and 1‐pentanol. The triplet lifetimes are all in the range 7–9 μs. The rate constant for electron transfer quenching of triplet thionine by iron(II) is higher in the anionic media due to a higher local Fe2+ concentration. However, the back reaction between semithionine and iron(III) is not similarly enhanced in the presence of micelles or microemulsion. The dismutation of semithionine is a little slower in microemulsion than in water, but over two orders of magnitude slower in SDS micelles. The quantum yield of thionine triplet formation, determined for surfactant thionine in SCS microemulsion, approaches unity.

Equilibrium vapor pressure in microemulsions: a test of the pseudophase model

The thermodynamic activities of oil (benzene) and alcohol cosurfactant have been determined in benzene/sec-butanol/water/surfactant microemulsions. The surfactants employed were sodium cetyl sulfate (anionic), cetyl trimethylammonium bromide (cationic), and Brij 96 (nonionic). The activities were determined by means of gas chromatographic headspace analysis. The results are interpreted in terms of the pseudophase model for microemulsions. The ionic systems appear to fit the model over most of the compositions in the microemulsion range of existence, while the nonionic system does not. For the ionic systems, the distribution of components among the domains of the microemulsion has been calculated.

DIFFUSION MEASUREMENTS IN MICROEMULSIONS

ABSTRACT We have carried out diffusion coefficient measurements in both aqueous micelles and microemulsions using the techniques of palaeography and quasielastic light scattering (QLS) The former method involves the determination of the diffusion coefficient of an electroactive oil soluble probe at a polarizable microelectrode. For high water content microemulsions, both methods yield the same diffusion coefficients, which can be identified as the self diffusion coefficient For cetyltrimethylammonium bromide (CTAB) micelles, both methods yield the same result at the salt (NaBr) concentration at which the QLS measurements are independent of CTAB concentration. In more concentrated microemulsions, QLS data gave diffusion coefficients in agreement with polarography only for a sodium cetyl sulfate (SCS) system at 65-75 wt % water. For the SCS microemulsions at 60% water, and CTAB microemulsion at 60-75% water, the QLS data yielded rapid, nonexponential decays. However, consistent polarographic diffusion coeff...

Effect of alkyl chain on the uptake, distribution, and excretion of 35S-labeled alkyl sulfates in carp

The effect of the number of carbons of the alkyl chain on the uptake, distribution, and excretion of a surfactant in fish was investigated using 35S-labeled alkyl sulfates ( 35SAS) of three different carbon numbers and carp. As a result, the radioactivity was found to be easily taken up into the fish body and distributed throughout the tissues and organs for any surfactant, but the concentration factors differed characteristically depending upon the number of carbons of the alkyl chain, i.e., 2.1, 11, and 73 for 35S-labeled sodium lauryl sulfate ( 35S-C12-AS), 35S-labeled sodium myristyl sulfate ( 35S-C14-AS), and 35S-labeled sodium cetyl sulfate ( 35S-C16-AS), respectively. And the distribution profile and excretion rate also tended to be affected by the number of carbons of the alkyl chain.

Hepatotoxic and cellular uptake interactions among surface active components of erythromycin preparations

Rat hepatoma cell cultures and Chang cell cultures derived from human liver were exposed to erythromycin estolate, erythromycin cetyl sulfate or to the individual components of these preparations, erythromycin propionate and sodium lauryl sulfate or erythromycin base and sodium cetyl sulfate respectively. Cytotoxicity was evaluated by leakage of cytoplasmic and lysosomal enzymes into the media. The uptake of the drugs by the cells was measured with radiolabeled compounds. The surface activity of the drugs was determined in vitro with a surface tension balance. Those drugs with the greatest surface activity were found to have the greatest cytotoxic effects on both cell culture lines. The cytotoxic effects of erythromycin cetyl sulfate were exclusively from the cetyl sulfate. With the erythromycin estolate combination, both lauryl sulfate and erythromycin propionate were cytotoxic. The presence of the latter increased the uptake of lauryl sulfate by the cells and resulted in a potentiation of the cytotoxic effect. Thus, the detergent ingredients used to enhance the gastrointestinal absorption of the drugs may also enhance their cell penetration and determine their hepatotoxicity in vitro; this form of cytotoxic drug interaction mechanism at the cellular level may explain the hepatotoxicity of some of these drugs in man.

The behaviour of dyes at oil/water interfaces

The adsorption of ionic dyes, the builder effect, and the interaction between ionic dyes and surface active agents were investigated by using the electrocapillarity at oil/water interfaces. The oil phase was the solution of tetra-butylammonium chloride, sodium cetylsulphate, cetylpyridinium chloride or stearylamine in methylisobutylketone, and the water phase contained various dyes in addition to the inorganic electrolyte. The interfacial tension decreased over the anodic (or cathodic) polarization range, when anionic (or cationic) dyes were added to the water phase, thus indicating the dye adsorption at the interface. The interfacial excess of dye ions was found to increase linearly with the cubic roots of dye concentration and of ionic strength of the water phase. The counterion binding took place at the oil/water interface between anionic (or cationic) dyes and positive (or negative) head groups of surface active agent ions adsorbed at the interface. It was found that the equilibrium constants of binding between anionic dyes and cationic surface active agents at the oil/water interface were of the same order of magnitude as, and a little larger than, those obtained at the water bulk phase.

The uptake of cetyltrimethylammonium bromide by Escherichia coli

Abstract THE uptake of cetyltrimethylammonium bromide (CTAB) by bacteria has previously been examined by Salton (1951) and by McQuillen (1950). Both workers determined its concentration in solutions by titration with sodium cetyl sulphate using pinacyanol bromide as indicator, and reported that uptake was in the form of a typical adsorption isotherm with saturation of the cells at an uptake equivalent to several theoretical close packed monolayers. This communication reports on studies of the uptake of 14C-labelled CTAB by cells of Escherichia coli and the concurrent release of phosphorus compounds from their metabolic pool.

Adsorption from aqueous solutions of ionic surface-active agents by gold. Part 2

The extent of adsorption by gold from aqueous solutions of a series of long-chain ammonium bromides has been measured and electrokinetic properties of gold in these solutions studied by microelectrophoresis. Froth flotation of gold particles has been studied in solutions of long-chain ammonium bromides, of long-chain pyridinium bromides and of the anionic compounds sodium cetyl sulphate and sodium dodecyl sulphate. In part 1, conclusions were drawn from adsorption and electrophoretic data regarding the modes of orientation of surfactant ions in the adsorbed layers; specific adsorption of surfactant anions but not of cations was postulated. The relative efficiencies of flotation reported here support those conclusions.

Permanganate–oxalic acid as a redox initiator in aqueous media. Part II. Kinetics and degree of polymerization

AbstractThe rate of polymerization of aqueous methyl methacrylate under nitrogen at 32°C. is proportional to the first power of catalyst (MnO4−) concentration (0.633 to 15.83 × 10−5 mole/l.) at fixed concentrations of the activator (0.8 × 10−2 mole/l.) and monomer (6.204 × 10−2 mole/l.), independent of activator concentration over a wide range (0.50 to 0.0625 × 10−2 mole/l.), and proportional to the first power of monomer concentration within the range (0.94 to 7.52 × 10−2 mole/l.) at fixed concentrations of the catalyst (3.16 × 10−6 mole/l.) and the activator (0.8 × 10−2 mole/l.). The initial rate of polymerization attains a maximum value at 45°C., but falls with further rise in temperature. The rate of polymerisation is depressed by agitation after initiation, salts and organic solvents, and is accelerated by MnSO4 and complexing agent like NaF (only at low monomer concentration), and in presence of peptizers like sodium cetyl sulfate or cetyltrimethylammonium bromide. The separating phase in the absence of peptizers is a course coagulum, and possibly a steady state with respect to radicals is not attained at high catalyst concentration. Injection of catalyst late in a run increases both the rate of polymerization and yield in unpeptized systems and does the reverse in peptized systems. The molecular weight of the polymers increases in the course of a run and is also affected by change of catalyst concentration but not by activator concentration in the range where the rate of polymerization is independent of activator concentration.

Hydrophobic monolayers on platinum, mica, and silica

The wetting behavior of plates of platinum, mica, and silica has been determined after their immersion in aqueous solutions of two anionic and two cationic detergents (sodium cetyl sulfate, potassium laurate, and cetyl trimethylammonium bromide, dodecyl trimethylammonium bromide) over the range of concentrations M to 10 −9 M . In general, a surface becomes hydrophobic to the solution at a low concentration but is completely wetted by a more concentrated solution (ca. 10 −3 M ) of the same compound. The anionic detergents, however, wet silica over the whole range of concentrations. The concentrations which define the limits of the hydrophobic range of solutions have been determined. These are interpreted in terms of adsorption of one or two monolayers of the long-chain ions at the liquid-solid interface.

Hydrophobic monolayers on platinum, mica, and silica

The wetting behavior of plates of platinum, mica, and silica has been determined after their immersion in aqueous solutions of two anionic and two cationic detergents (sodium cetyl sulfate, potassium laurate, and cetyl trimethylammonium bromide, dodecyl trimethylammonium bromide) over the range of concentrations M to 10 −9 M. In general, a surface becomes hydrophobic to the solution at a low concentration but is completely wetted by a more concentrated solution (ca. 10 −3 M) of the same compound. The anionic detergents, however, wet silica over the whole range of concentrations. The concentrations which define the limits of the hydrophobic range of solutions have been determined. These are interpreted in terms of adsorption of one or two monolayers of the long-chain ions at the liquid-solid interface.