Concentrations Of Sodium Lauryl Sulfate Research Articles

SLS/βCD-curcumin nanosuspension: Preparation, characterization and pharmacological evaluation

BackgroundThe primary aim of the study was to prepare SLS/βCD-curcumin nanosuspension and to assess its in-vivo wound healing efficacy. MethodSLS/βCD-curcumin nanosuspension was prepared based on nanoprecipitation method. Totally nine formulations were prepared to optimize various concentrations of sodium lauryl sulfate and β-cyclodextrin. Formulation FC3 with mean particle size of 206 nm, surface area of 53.4 m2/g, distribution width of 4.4 and uniformity of 0.956 was selected and carried forward for in-vivo wound healing activity in adult Wistar albino rats in comparison with control, ethanolic solution of curcumin and standard drug povidone iodine. ResultsSLS/βCD-curcumin nanosuspension and standard drug povidone iodine have shown significant (P < 0.001) percentage wound contraction in comparison with control. However, SLS/βCD-curcumin nanosuspension has produced comparable wound healing activity at about 25 times lesser dose than the standard drug povidone iodine. ConclusionsWe conclude that the prepared SLS/βCD-curcumin nanosuspension has offered significant size reduction to curcumin in nano range and contribute in enhancement of aqueous stability, solubility and reactability of curcumin at the site of wound and increased the therapeutic potency of SLS/βCD-curcumin nanosuspension in the treatment of wound.

Improvement of magnetic properties of electrodeposited CoNiMnP–BaFe12O19 nanocomposite coatings in presence of sodium lauryl sulphate

Electrodeposition is an attractive method for preparing electromagnetic micro-electromechanical system actuators, and composite electrodeposits incorporating ferromagnetic particles exhibit excellent magnetic properties. Thus, an increasing research effort has been made to optimising the electrodeposition of magnetic composite coatings. In the present paper, sodium lauryl sulphate has been introduced to improve the weight per cent of ferromagnetic particles embedded in CoNiMnP–BaFe12O19 composite coatings, and careful investigation of the effect of varying sodium lauryl sulphate concentration on the surface morphology, element weight fraction and magnetic properties of composite coatings, is carried out. The results demonstrate that the addition of sodium lauryl sulphate in the concentration range from 0·8 to 4 g L−1 favours the inclusion of magnetic particles into the alloy deposit; the maximum weight per cent of BaFe12O19 particles in the nanocomposite coatings, 18·28 wt-%, is acquired with the addition of 4 g L−1 sodium lauryl sulphate. However, it should be noted that the CoNiMnP–BaFe12O19 composite coatings with the highest BaFe12O19 weight fraction did not exhibit the highest coercivity and maximum energy density in the present experiment. The CoNiMnP–BaFe12O19 nanocomposite coatings with a high coercivity of 1438 Oe, a high retentivity of 0·39 T, and maximum magnetic energy density of 15·41 kJ m−3 have been obtained at a sodium lauryl sulphate concentration of 3 g L−1.

In vivo and in vitro analysis of low level light therapy: a useful therapeutic approach for sensitive skin

Sensitive skin is a relatively common dermatologic condition and no optimal treatments have been established so far. Low-level laser/light therapy (LLLT) has been used for its biostimulative effect in various clinical settings. The purpose of this study was to investigate whether low-level laser/light therapy can improve sensitive skin clinically and to evaluate the effects of LLLT on skin in vitro. Twenty-eight patients complaining of sensitive skin were treated with low-level polarized light, and clinical results were evaluated using subjective and objective method. To investigate possible working mechanism of LLLT on skin, cultured human keratinocytes pretreated with nontoxic concentration of sodium lauryl sulfate (SLS) were used. Cytokines released from irritated keratinocytes after LLLT were analyzed. All patients showed subjective and objective improvement after treatment. No adverse effects were reported. The average number of LLLT sessions required to achieve clinical improvement was 9.9, and cumulative dose of LLLT was 71.3 J/cm(2) on the average. Erythema index decreased significantly after LLLT treatment (p = 0.017). In vitro assay showed that LLLT significantly reduced the release of VEGF from SLS-pretreated keratinocytes (p = 0.021). Our results suggest that LLLT could be a useful and safe treatment modality for sensitive skin, and modification of inflammatory cytokines released from irritated keratinocytes may be considered as one of plausible mechanisms in sensitive skin treated with LLLT.

Effect of Dye Dispersion Preparation on Disperse Dyeing Performance on Polyester Fabric

The effect of dye dispersion preparation prior to dyeing on the dyeing ability of the disperse dye on polyester fabric was studied. The influence of sodium laurylsulphate (SLS) concentrations and the homogenization process was determined. The optimum SLS concentration for dyeing observed in this study was 0.01 M. The color yield of the dye passing through the homogenization process on polyester fabric was higher than that from the conventional dye preparation. Homogenization was also found to enhance disperse dyeability at a lower dyeing temperature. It infers that the dyeing process could be done at a lower temperature. The dyeing temperature could be as low as 110oC in the presence of homogenization. The effect of homogenization on the dyeability at different dyeing times was also examined.

The influence of surfactants and hydrolyzed proteins on keratinocytes viability and elasticity

The knowledge how surfactants and hydrolyzed proteins influence the elastic properties of living epidermal keratinocytes is sparse. We demonstrate that the stiffness of cells measured by atomic force microscope (AFM) can be correlated with viability test. The effects of sodium lauryl sulphate (SLS) and hydrolyzed collagen (HK) of molecular weight 9 kDa were examined with respect to human keratinocytes viability and elasticity. MTT assay was applied to determine the survival fraction of keratinocytes treated with SLS and HK solutions of various molar ratios. The AFM measurements of the keratinocytes stiffness were carried out immediately after the exposure of cells to the SLS and HK, respectively. The increase of the SLS concentration resulted in the decrease of cells proliferation and this effect was inhibited by addition of HK. The strongest inhibition was observed for the SLS:HK molar ratio equals to 2:1. AFM study shows decrease in the cell stiffness for cells treated with SLS. Fluorescence microscopy reveals remodeling of actin filaments of SLS-treated cells. SLS:HK mixture treatment results in mechanical stiffness close to untreated cells. These results provide possible correlations between mechanical properties and viability of keratinocytes when the chemical stress occurs.

Influence of substrate on corneal epithelial cell viability within ocular surface models

Corneal tissue engineering has improved dramatically over recent years. It is now possible to apply these technological advancements to the development of superior in vitro ocular surface models to reduce animal testing. We aim to show the effect different substrates can have on the viability of expanded corneal epithelial cells and that those which more accurately mimic the stromal surface provide the most protection against toxic assault. Compressed collagen gel as a substrate for the expansion of a human epithelial cell line was compared against two well-known substrates for modelling the ocular surface (polycarbonate membrane and conventional collagen gel). Cells were expanded over 10 days at which point cell stratification, cell number and expression of junctional proteins were assessed by electron microscopy, immunohistochemistry and RT-PCR. The effect of increasing concentrations of sodium lauryl sulphate on epithelial cell viability was quantified by MTT assay. Results showed improvement in terms of stratification, cell number and tight junction expression in human epithelial cells expanded upon either the polycarbonate membrane or compressed collagen gel when compared to a the use of a conventional collagen gel. However, cell viability was significantly higher in cells expanded upon the compressed collagen gel. We conclude that the more naturalistic composition and mechanical properties of compressed collagen gels produces a more robust corneal model.

Enantioseparation of Racemic Mixtures Based on Solvent Sublation

A method of solvent sublation was developed for the enantioseparation of racemic ofloxacin (rac Oflx) and racemic tryptophan (rac Trp). In this method, dibenzoyl-L-tartaric acid (L-DBTA) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) and sodium lauryl sulfate (SDS) were used as chiral coextractants and foamer, respectively. Several important parameters influencing the separation performances, such as pH in aqueous phase, concentrations of rac mixtures, L-DBTA, D2EHPA, and SDS, were investigated. Under the optimal operation conditions, the enantiomeric excess and enantioselectivity were 60.08% and 5.58 for Oflx and 65.09% and 6.31 for Trp, respectively. The yields of D-enantiomer and L-enantiomer were 34.23% and 8.54% for Oflx and 18.59% and 3.93% for Trp, respectively. The results suggest that the enantioselectivities have been enhanced compared with the traditional chiral extraction. This technique is an efficient chiral separation method, with many advantages such as low expenditures of organic solvent, low consumption of chiral extractant, and easy realization of multistage operation.

Online conductivity and stability in the emulsion polymerization of N‐butyl methacrylate: Nonreactive versus reactive systems

AbstractTwo different types of conductivity probes, that is, a torroidal probe and a resistance probe, were used as online sensors to monitor conductivity during the course of emulsion polymerizations of n‐butyl methacrylate (BMA). These measurements were first applied to a nonreactive system, but the results showed that this method cannot be used to monitor latex stability in this system. Batch emulsion polymerizations of BMA were then carried out using different concentrations (0.6, 1.2, 2.4, and 7.8 mM) of sodium lauryl sulfate (SLS) as surfactant. The profiles of the two conductivity curves changed with the variation of the SLS concentration. Because deposition of polymers on the surfaces of the electrodes of the resistance probe can reduce the measured conductivity values obtained from this probe (R) such that they are lower than the true values, as measured by the torroidal probe (T), the final conductivity ratio (R/T) between the two conductivity curves was chosen as a parameter to correlate the conductivity measurements to latex stability, which was estimated using blender tests and turbidity measurements. A linear relationship between them was found, indicating that the online conductivity measurements could be used to predict latex stability in the BMA emulsion polymerization system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Comprehensive study of dynamic curing effect on tablet coating structure

The dissolution method is still widely used to determine curing end-points to ensure long-term stability of film coatings. Nevertheless, the process of curing has not yet been fully investigated. For the first time, joint techniques were used to elucidate the mechanisms of dynamic curing over time from ethylcellulose (Aquacoat®)-based coated tablets. X-ray micro-computed tomography (XμCT), Near Infrared (NIR), and Raman spectroscopies as well as X-ray microdiffraction were employed as non-destructive techniques to perform direct measurements on tablets. All techniques indicated that after a dynamic curing period of 4h, reproducible drug release can be achieved and no changes in the microstructure of the coating were any longer detected. XμCT analysis highlighted the reduced internal porosity, while both NIR and Raman measurements showed that spectral information remained unaltered after further curing. X-ray microdiffraction revealed densification of the coating layer with a decrease in the overall coating thickness of about 10μm as a result of curing. In addition, coating heterogeneity attributed to cetyl alcohol was observed from microscopic images and Raman analysis. This observation was confirmed by X-ray microdiffraction that showed that crystalline cetyl alcohol melted and spread over the coating surface with curing. Prior to curing, X-ray microdiffraction also revealed the existence of two coating zones differing in crystalline cetyl alcohol and sodium lauryl sulfate concentrations which could be explained by migration of these constituents within the coating layer. Therefore, the use of non-destructive techniques allowed new insights into tablet coating structures and provided precise determination of the curing end-point compared to traditional dissolution testing. This thorough study may open up new possibilities for process and formulation control.

Cefuroxime axetil loaded gastroretentive floating tabletsbased on hydrophilic polymers: preparation and in vitro evaluation

The aim of this work was to study the formulation and in vitro characterization of hydro dynamically balanced floating matrix tablets using Cefuroxime axetil (CA) as model drug. Different excipients such as hydroxy propyl methyl cellulose (HPMC) K15M, E5LV (gelling agent), sodium bicarbonate (gas generating agent) and sodium lauryl sulfate (SLS) (solubility enhancer) were used in order to optimize the drug release profile as well as floating property. Decrease in release characteristics with high viscous polymer were observed due to increased gel strength, tortuosity and length of drug diffusion path. Significant difference (p<0.5) in release rate was found at different concentration of SLS. The release mechanisms were explored and explained with zero order, first order, Higuchi, Korsmeyer and Hixson-Crowell equations. The release rate, extent and mechanism were governed by the content of polymer. The polymer content and amount of floating agent significantly affected the time required for 50%of drug release (t50%), mean dissolution time (MDT), release rate constant, and diffusion exponent (n).Kinetic modeling of dissolution profile revealed that the drug release mechanism could range from diffusion controlled to case II transport, which was co-dominated by diffusion polymer erosion in the release mechanism.

The role of the skin irritation response in polysensitization to fragrances

Contact allergy to fragrance chemicals is an increasing problem. Polysensitization is likely to be a phenotype of increased susceptibility to contact allergy. The factors that play a role in polysensitization are largely unknown. Identifying these risk factors is important with regard to future studies on the aetiology of contact allergy. To investigate whether enhanced skin irritability is a risk factor for the development of polysensitization to fragrance chemicals. One hundred participants characterized by fragrance contact allergy were included in our study. The participants were patch tested on the back with 25 individual fragrance chemicals and fragrance mixes I and II, and on the upper arm with sodium lauryl sulfate (SLS) (consisting of SLS concentrations of 0.45%, 0.67%, 1%, and 1.5%). Reading of both tests was performed during the following visits at days 2, 3, and 7. The response to SLS was monitored by measuring transepidermal water loss (TEWL). Polysensitization was defined as three or more allergic reactions to non-cross-reacting fragrance chemical allergens. Individuals with polysensitization showed significantly higher irritation responses to SLS 1% and 1.5% as assessed by TEWL. We found an enhanced skin irritation response to be a risk factor for the development of polysensitization to fragrance chemicals.

Poly(PEGDMA‐MAA) copolymeric micro and nanoparticles for oral insulin delivery

AbstractPoly(ethylene glycol) dimethacrylate (PEGDMA) and methacrylic acid (MAA) based micro and nanoparticles were prepared and evaluated as a carrier for oral delivery of insulin. PEGDMA was synthesized by esterification reaction of the PEG4000 with MAA in the presence of an acid catalyst. Particles of different size were prepared by emulsion polymerization reaction using different concentration of sodium lauryl sulphate (SLS) as an emulsifying agent. Synthesized copolymeric particle were characterized by attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR), scanning electron microscopy, and acid value. The mean particle diameter of the polymeric micro and nanoparticles at various physiologically relevant pH values was measured using dynamic light scattering. Insulin loading efficiency of the particles was found to be directly proportional to the particle size and inversely proportional to the acid value of the particles. In vitro insulin release studies from various insulin loaded particles were performed by simulating the gastrointestinal tract conditions using HPLC. At pH 2.5, the release of insulin from polymeric particles was observed in the range of 5–8% while a significant higher release (20–35%) was observed at pH 7.4 during first 15 min of in vitro release. Largest size copolymeric particles of 8.3 µm also showed the highest efficiency to reduce the blood glucose level in diabetic rabbits. Copyright © 2010 John Wiley &amp; Sons, Ltd.

Solution-Mediated Phase Transformation of Haloperidol Mesylate in the Presence of Sodium Lauryl Sulfate

Forming a salt is a common way to increase the solubility of a poorly soluble compound. However, the solubility enhancement gained by salt formation may be lost due to solution-mediated phase transformation (SMPT) during dissolution. The SMPT of a salt can occur due to a supersaturated solution near the dissolving surface caused by pH or other solution conditions. In addition to changes in pH, surfactants are also known to affect SMPT. In this study, SMPT of a highly soluble salt, haloperidol mesylate, at pH 7 in the presence of a commonly used surfactant, sodium lauryl sulfate (SLS), was investigated. Dissolution experiments were performed using a flow-through dissolution apparatus with solutions containing various concentrations of SLS. Compacts of haloperidol mesylate were observed during dissolution in the flow-through apparatus using a stereomicroscope. Raman microscopy was used to characterize solids. The dissolution of haloperidol mesylate was significantly influenced by the addition of sodium lauryl sulfate. In conditions where SMPT was expected, the addition of SLS at low concentrations (0.1-0.2 mM) reduced the dissolution of haloperidol mesylate. In solutions containing concentrations of SLS above the critical micelle concentration (CMC) (10-15 mM), the dissolution of haloperidol mesylate increased compared to below the CMC. The solids recovered from solubility experiments of haloperidol mesylate indicated that haloperidol free base precipitated at all concentrations of SLS. Above 5 mM of SLS, Raman microscopy suggested a new form, perhaps the estolate salt. The addition of surfactant in solids that undergo solution-mediated phase transformation can add complexity to the dissolution profiles and conversion.

Resolution of Racemic Ofloxacin Based on Co-Technology of Bubble Fractionation and Extraction

A method of bubble fractionation, with the help of solvent extraction, was developed for the resolution of racemic ofloxacin (rac OFLX). In this method, dibenzoyl-L-tartaric (L-DBTA), di-(2-ethylhexyl) phosphoric acid (D2EHPA) and sodium lauryl sulfate (SDS) were used as chiral collector, co-extractant and foamer, respectively. Several important parameters influencing the resolution performances, such as pH in aqueous phase, concentration of OFLX, concentration of L-DBTA, concentration of SDS and volume ratio of D2EHPA to n-octanol in solution, were investigated. The optimal resolution conditions were obtained with the aqueous phase pH 7, volume ratio of D2EHPA to n-octanol 6/14 in organic phase, concentration of SDS 0.42 mg mL−1, concentration of OFLX 1.67 mg mL−1, and concentration of L-DBTA 0.11 g mL−1. Under the optimal extraction conditions, the enantiomeric excess value (e.e.%) was 60.08% and the enantioselectivity (α) was 5.58. It was found that the capacity of enantioselective separation can be greatly improved by the co-technology.

CONTINUOUS FOAM SEPARATION OF HEAVY METAL IONS FROM ELECTROPLATING INDUSTRIAL EFFLUENT

Process industries generate a large amount of waste materials during either production or downstreaming operations. Among many methods available for their separation, foam separation plays a major role, especially when the concentration of undesirable components involved is very low. The success of this technique depends on the stability and characteristics of the foam. This operation is simple with less maintenance as there are no moving parts. In the present study, simultaneous removal of metal ions such as chromium (VI), copper (II), and zinc (II) from electroplating industrial effluent was carried out with sodium lauryl sulfate (SLS) as surfactant in continuous foam column. Enrichment ratios of 3.94, 4.05, and 7.96 with a percentage removal of 59.0%, 63.0%, and 99.2% were obtained for chromium (VI), copper (II), and zinc (II) ions respectively at the optimum operating parameters of 23 cm liquid pool height in column, 0.1 liter per minute (Lpm) of airflow rate, feed flow rate of 4 liters per hour (Lph), 0.1% (w/v) of SLS concentration, pH of 6.0, and at feed concentrations of 32.5, 27.0, and 23.0 ppm for chromium (VI), copper (II), and zinc (II) ions respectively. Enrichment ratio was found to increase with an increase in feed flow rate. With a decrease in concentration of the bulk solution, the separation factor was found to increase. The study indicates the feasibility of continuous foam separation for treating industrial effluents.

POLIMERISASI EMULSI ETIL AKRILAT: PENGARUH KONSENTRASI SURFAKTAN, INISIATOR DAN TEKNIK POLIMERISASI TERHADAP DISTRIBUSI UKURAN PARTIKEL

Emulsion Polymerization of Etyl Acrylate: The Effect of Surfactant, Initiator Concentration and Polymerization Technique on Particle Size Distribution. Emulsion polymerization was conducted using ethyl acrylate monomer. The effect of sodium lauryl sulfate concentration, ammonium persulfate concentration, the various of polymerization techniques and feeding time to the conversion, particle size and its distribution were observed. The purpose of this research is to obtain the optimum condition of ethyl acrylate homopolymer with particle size around 100 nm, to get the particle size distribution monodisperse and to get solid content value of the experiment closed to its theoretical value. The optimum condition then could be applied in shell polymerization of core-shell polymers. The results of the research showed that semicontinuous technique obtained optimum sodium lauryl sulfate concentration at 20 CMC (critical micelle concentration) and ammonium persulfate concentration is 3%. By using batch technique that the biggest particle size is 123 nm with conversion 95.8% and monodisperse. The shorter of feeding time the more monomer of ethyl acrylate being polymerized, it is showed by the higher conversion up to 94.4% and the bigger particle size is 107.9 nm.

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.

Stability, Release Property and Skin Penetration of Stearic Acid Nanoparticles

Stearic acid nanoparticles were prepared by a melt-emulsification method. The nanoparticles were stable in terms of the size and the appearance when the concentrations of sodium lauryl sulfate in the suspensions were less than 1.443%. And, they were stable in the aspect of their integrity when the concentrations of ethanol in the suspensions were less than 20%. For the release and the skin permeation experiment, hinokitiol (HKL) was used as a model drug and it was encapsulated in the nanoparticles. The % release of HKL was observed in distilled water and alcoholic solutions of 5% and 10%. The release increased up to 45%–55% for the first 8 h and thereafter no significant release was observed. According to the results of a confocal laser scanning microscopy, the nanoparticles were found to be in the dermis of a hairless mouse skin. The nanoparticles present in the dermis would act as depots for the dermal delivery of HKL.

Photooxidation of anionic surfactant (sodium lauryl sulfate) in a three-phase fluidized bed reactor using TiO 2/SiO 2 photocatalyst

The photooxidation of sodium lauryl sulfate (=sodium dodecyl sulfate) in two different types of three-phase fluidized bed reactors was investigated. A low concentration of sodium lauryl sulfate (0.1–0.6 mM) in aqueous solution was photocatalytically decomposed by a TiO 2 photocatalyst immobilized on a porous SiO 2 support. In order to determine the optimum operating conditions in the fluidized beds, the effects of the air flow rate, amount of catalyst, initial concentration of surfactant, light source power, and pH on the photooxidation rate were investigated. From the experimental results, it was observed that the superficial air velocity was an important parameter in determining the reaction rate for both reactors. The photooxidation reaction rate increased with increasing UV lamp power and the experimentally obtained reaction rates showed good agreement with the Langmuir adsorption model. Also, a higher reaction rate was observed when the aqueous solution was acidic.

Control of pore size in ceramic foams: Influence of surfactant concentration

The role of sodium lauryl sulfate (SLS) on pore size of ceramic foams has been investigated using silica foams with 65–70% porosity prepared by a mechanical foaming and gelcasting method. Experiments were carried out to determine bubble size and stability of three-phase foams as well as the pore size of ceramic foams under a range of SLS concentration. Results suggested that pore size of ceramic foams is successfully controlled by changing the SLS concentration of three-phase foam slurries. The controllable range of pore size in this study was roughly 70–150μm, which corresponded to the SLS concentration range between 7×10−3 and 7×10−2M. Furthermore, it was found that the SLS concentration significantly influenced on the foam stability during post-foaming processes as well as the initial bubble size.