Absence Of Sodium Lauryl Sulfate Research Articles

The effectiveness of dentifrices without and with sodium lauryl sulfate on plaque, gingivitis and gingival abrasion--a randomized clinical trial.

ObjectivesThe aim of this study was to compare the efficacy of a dentifrice without sodium lauryl sulfate (SLS) to a dentifrice with SLS in young adults aged 18–34 years on gingivitis.Material and methodsOne hundred twenty participants (non-dental students) with a moderate gingival inflammation (bleeding on probing at 40–70 % of test sites) were included in this randomized controlled double blind clinical trial. According to randomization, participants had to brush their teeth either with dentifrice without SLS or with SLS for 8 weeks. The primary outcome was bleeding on marginal probing (BOMP). The secondary outcomes were plaque scores and gingival abrasion scores (GA) as well as a visual analogue scale (VAS) score at exit survey. Baseline and end differences were analysed by univariate analysis of covariance (ANCOVA) test, between group differences by independent t test and within groups by paired sample t test.ResultsBOMP improved within groups from on average 0.80 at baseline to 0.60 in the group without SLS and to 0.56 in the group with SLS. No statistical difference for BOMP, plaque and gingival abrasion was found between both groups. VAS scores for taste, freshness and foaming effect were significantly in favour of the SLS-containing dentifrice.ConclusionThe test dentifrice without SLS was as effective as a regular SLS dentifrice on gingival bleeding scores and plaque scores. There was no significant difference in the incidence of gingival abrasion.Clinical relevanceIn patients diagnosed with gingivitis, a dentifrice without SLS seems to be equally effective compared to a dentifrice with SLS and did not demonstrate any significant difference in gingival abrasion. In patient with recurrent aphthous ulcers, the absence of SLS may even be beneficial. However, participants indicate that they appreciate the foaming effect of a dentifrice with SLS more.

Electrochemically Prepared Manganese Oxide as a Cathode Material for a Microbial Fuel Cell

This work describes the construction of a mediatorless microbial fuel cell (MFC) using the microorganism Acetobacter aceti as the biocatalyst in the anode compartment with glucose as a fuel. The periplasmic membrane bound pyrroloquinoline quinone (PQQ) containing enzymes of these genera provide fast and highly efficient oxidation of a wide variety of substrates and helps in the direct routing of electrons to the anode. We describe our preliminary findings with regard to the use of electrochemically deposited manganese oxide films on carbon substrates as cathode materials in MFCs. Manganese oxide was electrochemically deposited on carbon paper in the presence and in the absence of the surfactant, sodium lauryl sulfate (SLS). Electrochemical characterizations of the electrodeposited films are carried out by cyclic voltammetry and impedance spectroscopy. Structural characterization of the film is carried out by XRD, XPS, and SEM. The XPS studies reveal that the presence of Mn4+ (as MnO2) in the absence of SLS and Mn3+/2+ (as Mn3O4or Mn2O3 or MnOOH) ion in the presence of SLS. The power output obtained from MnO2 cathode was 666 ± 9 mW m−3 and it is the highest value reported for MFCs with cubical configuration with the same cathode.

Effect of surfactant on high capacitance of galvanostatically deposited MnO2

Manganese dioxide has been galvanostatically deposited on stainless-steel substrate from an aqueous acidic solution of manganese sulphate (1M) in presence of a surface active agent (surfactant), namely, sodium lauryl sulphate (SLS), for supercapacitor applications. The deposits have been developed under different conditions of SLS and their specific capacitance is measured by cyclic voltammetry (CV) and also by galvanostatic charge/discharge cycle. The oxide film (∼0.1mgcm−2) anodized from the manganese solution at 2.0mAcm−2 has shown the highest specific capacitance of 255.8F g−1, at scan rate of 10mVs−1. It is observed that the capacitance increased by about 40% compared to the oxide prepared in the absence of SLS. Improved specific capacitance is due to the effect of the surfactant molecules in the deposit, causing high surface area of the deposit. The deposit is found to display good cycleability, even up to 1500 cycles. The structure and surface morphology of the deposits have been studied by means of X-ray diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). XRD study reveals that crystallinity of the deposit with SLS remains unchanged, both are amorphous in nature. The surface area of the deposit is found to increase considerably due to the effect of SLS, as evident by SEM study.

The influence of additives on the in vitro release of drugs from hard gelatin capsules.

Abstract A factorially designed experiment has been used to assess the total percentage of drug released from hard gelatin capsules in vitro as a function of (a) the drug—the drugs being nitrofurantoin, nitrofurazone, oxytetracycline dihydrate and tetracycline hydrochloride; (b) the diluent—the diluents being lactose, Primojel and Dry-Flow starch; (c) the quantity of diluent, either 20 or 80%; (d) the presence (at a 1 % level) and absence of magnesium stearate and (e) the presence (at a 1 % level) and absence of sodium lauryl sulphate. Treatment of the results by analysis of variance, in 5,4, 3 and 2 factor combinations, indicates that the influence of a given factor is often dependent on the other factors. These interdependencies take the form of either a variation in the extent of an effect or the reversal of an effect. The influence of drug and level of diluent show interdependencies of the former kind. Hence, whilst the overall average for drug release indicates that the drugs can be ranked in the ascending order: nitrofurantoin < nitrofurazone < oxytetracycline < tetracycline, the interactions predict that the quantitative ratios of 1:1·8:2·7:5·1 for the drugs above will vary when an additive is present and according to the additive. The rank order will, however, remain unchanged. Similarly, the higher level of diluent will usually increase drug release but not by a constant ratio between drugs. A reversal of an effect is shown by the addition of magnesium stearate, which in some instances increases rather than decreases drug release (its more usual effect). The addition of 1 % sodium lauryl sulphate does not provide a major enhancement of drug release, and in certain cases can be detrimental. There is no consistent order of effectiveness of the three diluents, and thus a universal capsule diluent, which will always improve drug release, does not appear to be a possibility.

THE EFFECT OF DIFFERENT SURFACTANTS ON DISSOLUTION RATE OF RECRYSTALLIZED INDOMETHACIN

The effects of crystallization of indomethacin as a poorly water-soluble drug in aqueous surfactant solutions (using the basket method), on the drug dissolution behavior was investigated.A significant enhancement of drug dissolution was observed for for the dissolution rates of crystals treated with hydrophilic surfactants, Tween 80 and sodium lauryl sulfate (SLS). However, asing Arlacel 60 as a hydrophobic surfactant incrystallization medium decreased the indomethacin dissolution rate. Differential scanning calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FT-IR) indicated the existence of both ? and ?- polymorphs of indomethacin (with different percentages). The FT-IR results also showed that, only the ?- form could be detected in indomethacin crystals without any surfactant. These results were also confirmed by X-ray powder diffraction and scanning electron microscopy (SEM). The nuclear magnetic resonance (NMR) studies demonstrate the presence of a small amount of Tween 80 and the absence of SLS in the treated crystals. In this study, we concluded that, the presence of small amounts of surfactant, adsorption of surfactant onto the crystal surface and the decrease in powder bulk density could be the possible mechanisms of alteration in the dissolution rate of crystals treated with Tween 80, Arlacel 60 and SLS respectivelyAntioxidant.

A New HPLC Approach for the Determination of Hydrophilic and Hydrophobic Components: The Case of Pseudoephedrine Sulfate and Loratadine in Tablets

Effective isocratic separations of decongestants and antihistamines is a challenging analytical task due to wild differences in their lipohilicities (hydrophilic decongestants and hydrophobic antihistamines). In this paper a new approach for resolving such a problem is described taking pseudoephedrine sulfate and loratadine as an example. The chromatographic behavior of pseudoephedrine sulfate and loratadine on RP C18 and C8 columns were studied in presence and absence of sodium lauryl sulfate (SLS). The effect of combining two different types of stationary phases (cyano and C18 or C8) on the relative retention of the two compounds was investigated. In conclusion, it was found that the combination of a C18 column followed by a standard cyano column provides a stationary phase that separates both compounds effectively and within a reasonable time. This approach was compared to a literature method and demonstrated to have superior selectivity.

Synergistic Effect of Low‐Frequency Ultrasound and Sodium Lauryl Sulfate on Transdermal Transport

Application of low‐frequency ultrasound has been shown to enhance transdermal transport of drugs (low‐frequency sonophoresis). In this paper, we show that the efficacy of low‐frequency ultrasound in enhancing transdermal transport can be further increased by its combination with sodium lauryl sulfate (SLS), a well‐known surfactant. The dependence of the ultrasound–SLS‐mediated transport on ultrasound parameters, including intensity, net exposure time, and duty cycle, is discussed. The transdermal transport enhancement is proportional to ultrasound intensity as well as to exposure time, and is independent of duty cycle as long as the net exposure time is the same. The synergistic effect of SLS and ultrasound on transdermal transport increases linearly with SLS concentration. The enhancement is also proportional to the ultrasound energy density beyond a threshold value, which suggests that a certain minimum amount of energy density is required before noticeable changes in skin permeability occur. A similar dependence of the transdermal transport enhancement on energy density is observed in the case of the enhancement induced by ultrasound alone. Although the threshold energy density value in the presence of SLS is about 10 times lower than that in the case of ultrasound alone, the relationship between enhancement and energy density in the presence and in the absence of SLS is otherwise similar. Possible mechanisms for the synergistic effect of ultrasound and SLS are also discussed. © 2000 Wiley‐Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 89: 892–900, 2000

Retinol-binding protein isolated from eel serum.

After a single-step density gradient ultracentrifugation of eel serum, distribution of retinol was investigated. Proteins of density above 1.21g/ml contained 65% of whole serum retinol, and high density lipoprotein and very low density lipoprotein contained 18 and 5%, respectively. Retinol-binding protein (RBP) was purified from proteins of density above 1.21g/ml using DEAE-TOYOPEARL, TOYOPEARL HW-50, and polyacrylamidegel electrophoresis (PAGE). When PAGE of partially purified RBP obtained from rechromatography of DEAE-TOYOPEARL was performed in the absence of sodium lauryl sulfate (SDS) and 2-mercaptoethanol, holo-RBP and apo-RBP were separated. Molecular weight of RBP was determined by SDS-PAGE to be 21, 000 to 22, 000 and amino acid composition of RBP was comparable to that of human RBP.

Electrophilic Aromatic Substitution Reactions. Part-II. Iodination of Aniline, Phenol and Anisole with Iodine Monochloride in Presence and Absence of Sodium Lauryl Sulphate in Aqueous Methanol-A Comparative Kinetic Study

Electrophilic Aromatic Substitution Reactions. Part-II. Iodination of Aniline, Phenol and Anisole with Iodine Monochloride in Presence and Absence of Sodium Lauryl Sulphate in Aqueous Methanol-A Comparative Kinetic Study

Purification of lactate dehydrogenase isoenzymes one, two, and three from human erythrocytes.

Lactate dehydrogenase (LD) isoenzymes 1, 2, and 3 were prepared from human erythrocytes by sequential ion-exchange chromatography followed by general-ligand (AMP analog) affinity chromatography. Respective yields, purification factors, and specific activities (kU per gram of protein) were 25%, 4394-fold, and 209.7; 40% 4385-fold, and 199.1; and 18%, 7565-fold, and 192.9. The respective preparations contained less than 0.5% of contaminating LD isoenzyme activity as judged from electrophoresis on thin-layer agarose, were homogeneous as judged by electrophoresis on polyacrylamide gel (both in the presence and absence of sodium lauryl sulfate), and showed minor contamination by other LD isoenzymes as judged by analytical isoelectric focusing. We think that these preparations would be useful as human-based calibrating or reference materials. Their purity is such that these preparations could also be used as antigens for the development of suitable antisera.

Increased level of cAMP in the rat intestinal musosa caused by sodium lauryl sulphate

The level of cyclic AMP in the jejunal mucosa from tied loops of anaesthetized rats was found to be significantly increased (27-50%) when sodium lauryl sulphate (SLS) was added to the loop fluid (2-27 mM). Imidazole (25 mM) did not significantly alter the resting level of cyclic AMP, but reduced the increase caused by SLS (17 mM). Theophylline (25 mM) significantly increased the intestinal level of cyclic AMP, and potentiated the increase caused by SLS. Ouabain (2.5 mM) did not alter the level of cyclic AMP in the presence or in the absence of SLS. The results of previous experiments on the increases in intestinal absorption caused by SLS or by dibutyryl cyclic AMP (Briseid et al., 1974, 1976) are discussed in light of the present data. It is concluded that the SLS-effect on absorption can only partly by ascribed to its effect on the intestinal level of cyclic AMP.

Increased intestinal absorption in the rat caused by sodium lauryl sulphate, and its possible relation to the cAMP system

The increases in the absorption of ouabain, phenolsulphonphthalein and pralidoxime caused by 17 mM sodium lauryl sulphate (SLS) from jejunal loops of anaesthetized rats were significantly reduced if sodium and chloride (Briseid et al., 1974) or chloride and bicarbonate were replaced by other ions in the loop fluid. Separate substitutions of sodium, chloride of bicarbonate did not significantly alter the SLS-caused absorption, except that the substitution of choline for sodium reduced the absorption of pralidoxime, both in the presence and in the absence of SLS. The increases in the absorption of phenolsulphonphthalein and pralidoxime caused by SLS were potentiated by theophylline (25 mM) and reduced by imidazole (25 mM). The addition of dibutyryl cyclic AMP (2.5 mM) to the loop fluid increased this absorption of the test substances. This effect was reduced by imidazole, but under the experimental conditions it was not potentiated by theophylline. Determinations of cyclic AMP in the rat intestinal mucosa showed that the level of this substance was significantly higher in the presence than in the absence of SLS. The experimental conditions were as described for the absorption experiments. It is concluded that the data obtained support the idea of an increased level of cyclic AMP as the main basis for the effect of SLS on the absorption.

The motion of drops in water contaminated with a surface-active agent

Measurements of the terminal velocity, the frequency of oscillation and the eccentricity are presented for drops of purified dichloroethane falling through water contaminated with known amounts of sodium lauryl sulphate. Details are also given of the structure and size of the attached wake. The results are compared with the results obtained for solid spheres falling through water and also with the correlations obtained by other workers for systems which had not been carefully purified. At low concentrations of sodium lauryl sulphate (viz 10 −5 g/l.) the results were consistent with the results obtained in the absence of sodium lauryl sulphate. When the system was contaminated grossly but to different degrees (viz 10 −2 and 10 −1 g/l.) the results were again consistent but differed from the results obtained for the purified system. Previous correlations, obtained for systems which had not been carefully purified, agreed with the results for the grossly contaminated system.

Base composition and column chromatography studies of ribonucleic acid differentially extracted from pea roots with sodium lauryl sulfate or p-amino salicylate

Three-day-old pea roots, aseptically grown, were incubated for 2 hr in 32P phosphate and extracted by the phenol method in the absence of sodium lauryl sulfate or p-amino salicylate. One or the other of these compounds was then added and the residue was re-extracted. RNA obtained by the re-extraction with either compound was of higher specific activity and contained a higher mole percent AMP than the RNA from the first extraction. A small part of the AMP-rich RNA eluted with DNA during chromatography on methylated albumin kieselguhr columns, but most of it adhered to the columns. Presence of unlabelled carrier nucleic acids had no measurable effect on the elution pattern.