sodium-dodecyl-sulfate and sodium-laureth-sulfate

New concepts of the horny layer as a metabolically active part of the epidermal permeability barrier elicited a re-evaluation of conventional mechanisms of occupational skin protection. Both skin protection products and noxae must penetrate the horny layer of the skin to be effective. The isolated perfused bovine udder skin (BUS) model reflects the natural penetration pattern; hence skin irritation, penetration and absorption can be investigated simultaneously. Using whole skin biopsies the degree of irritation in untreated (control), treated and pre-treated skin is measured by assessing the irritancy (PGE2-concentration) and cytotoxicity (MTT assay) after the exposure period of 0.5 h, 1.0 h and 5.0 h. Two types of skin protection studies were reported. One was a laboratory study using the water-soluble sodiumlaurylsulphate (10%, 15%) as noxa. The other study was initiated by a severely skin irritating water-soluble coolant (approx. 5%). This well documented case occurred in a metal working plant. In both studies different degrees of protective potential against the model noxae SLS and the coolant could be observed.

Topics: Animal Testing Alternatives; Animals; Cattle; Dinoprostone; Dose-Response Relationship, Drug; Humans; Irritants; Mammary Glands, Animal; Occupational Exposure; Skin; Skin Tests; Sodium Dodecyl Sulfate; Time Factors; Tissue Culture Techniques

Elevated levels of skin sebum are associated with the growth of Propionibacterium acnes. Intensive degreasing of the skin reduces Propionibacterium acnes but also may cause skin irritation.. We assessed the degreasing effect and skin tolerability of a botanical face cleanser with hops and willow bark extract and disodium cocoyl glutamate as mild cleansing agent compared to a standard face cleanser with sodium laureth sulfate (SLES).. A total of 21 healthy volunteers with normal to oily skin were enrolled in this study. Both cleansers were applied twice a day on the left or right side of the forehead for 15 days in a standardized manner. Bioengineering measurements were performed on day 8 and 15 and on day 17 after an application break of 48 hours. The sebum level was determined using a Sebumeter. The botanical face cleanser significantly reduced the sebum level (P < .01) in the test area on day 17. The SLES containing cleanser showed a statistically relevant degreasing effect already on day 15, but after the application break the sebum level increased again on day 17. None of the cleansers caused skin irritation as determined by skin redness measurements.. In contrast to the SLES containing cleanser, the botanical skin cleanser with hops and willow bark extract had a continuous degreasing effect without reactive seborrhoe after the treatment break. Skin cleansing without SLES might be advantageous for sensitive skin.

Topics: Adult; Erythema; Female; Healthy Volunteers; Humans; Male; Middle Aged; Photometry; Plant Extracts; Sebum; Severity of Illness Index; Skin; Skin Cream; Sodium Dodecyl Sulfate; Treatment Outcome; Young Adult

Compared to exaggerated hand washing procedures, an open non-exaggerated assay better approximates consumer surfactant use. Our goal was to observe skin surface modifications induced by an open test with regard to discriminating between surfactant solutions. This human in vivo assay provided information about the effect of only three washes at the laboratory and a week of at-home use. Dorsal hand and volar forearm were compared. The results demonstrated that this clinical model permits exploration of subclinical surfactant-induced irritation. Both the volar forearm and the dorsal hand are capable of discriminating between the effects of sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES). Squamometry proved to be a sensitive assessment technique for detecting surfactant-induced subclinical skin surface alterations and for differentiating surfactant effects in this open application assay, in as few as three washes.

Topics: Adult; Coloring Agents; Female; Hand Disinfection; Humans; Irritants; Male; Middle Aged; Skin; Sodium Dodecyl Sulfate; Surface-Active Agents

To avoid the acute irritation and dryness that a single occlusive surfactant application (24-h patch test) may cause, and to approximate clinical use, an open application model was chosen to define subclinical non-erythematous irritation in the stratum corneum. This human test combined a supervised washing at the laboratory with at-home use of the test products by the subjects. Effects of washing with the surfactants on the dorsal hand and volar forearm were compared. The results demonstrated that this situational use model permits the exploration of subclinical surfactant-induced irritation. The forearm appeared to be more discriminative as compared to the dorsal hand. Squamometry proved to be a sensitive, complementary assessment method for detecting surfactant-induced subclinical skin surface alterations and for differentiating surfactant effects in this open assay.

Topics: Adult; Confidence Intervals; Dermatitis, Irritant; Female; Humans; Male; Middle Aged; Patch Tests; Reference Values; Sensitivity and Specificity; Severity of Illness Index; Skin; Sodium Dodecyl Sulfate; Surface-Active Agents

Topics: Animals; Antioxidants; Biomarkers; Carps; Cetylpyridinium; Cytochrome P-450 Enzyme System; Ligands; Molecular Docking Simulation; Oxidative Stress; Sodium Dodecyl Sulfate; Surface-Active Agents

The purpose of this work is to evaluate the homology modeling,

Topics: Animals; Carps; Cetylpyridinium; Hematology; Molecular Docking Simulation; Sodium Dodecyl Sulfate; Surface-Active Agents

Our skin is continuously exposed to different amphiphilic substances capable of interaction with its lipids and proteins. We describe the effect of a saponin-rich soapwort extract and of four commonly employed synthetic surfactants: sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES), ammonium lauryl sulfate (ALS), cocamidopropyl betaine (CAPB) on different human skin models. Two human skin cell lines were employed: normal keratinocytes (HaCaT) and human melanoma cells (A375). The liposomes consisting of a dipalmitoylphosphatidylcholine/cholesterol mixture in a molar ratio of 7:3, mimicking the cell membrane of keratinocytes and melanoma cells were employed as the second model. Using dynamic light scattering (DLS), the particle size distribution of liposomes was analyzed before and after contact with the tested (bio)surfactants. The results, supplemented by the protein solubilization tests (albumin denaturation test, zein test) and oil emulsification capacity (using olive oil and engine oil), showed that the soapwort extract affects the skin models to a clearly different extent than any of the tested synthetic surfactants. Its protein and lipid solubilizing potential are much smaller than for the three anionic surfactants (SLS, ALS, SLES). In terms of protein solubilization potential, the soapwort extract is comparable to CAPB, which, however, is much harsher to lipids.

Topics: 1,2-Dipalmitoylphosphatidylcholine; Betaine; Biomimetics; Cell Line; Cell Survival; Cholesterol; Emulsifying Agents; Humans; Hydrogen-Ion Concentration; Keratinocytes; Liposomes; Models, Biological; Particle Size; Plant Extracts; Saponaria; Saponins; Skin; Sodium Dodecyl Sulfate; Surface-Active Agents; Triterpenes; Zein

The method of colloid titration with poly(diallyldimethylammonium) chloride has been improved to detect the endpoint with an off-vessel light reflectance sensor. The digital color sensor used measures light reflectance by means of light guides, with no immersion into the reaction solution. In such a method, the optical signal is free of disturbances caused by sticky flocs in the solution. The improved automatic titration set was applied for the determination of sodium laureth sulfate (SLES) in industrial batches and commercial personal care products. The sample color and opacity do not disturb the SLES quantification. When the SLES content lies in the range from 5% to 9%, the optimal sample weight is from 6 g to 3 g.

Topics: Colloids; Cosmetics; Image Processing, Computer-Assisted; Light; Reference Standards; Sodium Dodecyl Sulfate; Solutions; X-Ray Diffraction

Sodium laureth sulfate (SLES) and fatty acids are common ingredients in many cosmetic products. Understanding how neutral and charged fatty acid compounds partition between micellar and water phases is crucial to achieve the optimal design of the product formulation. In this paper, we first study the formation of mixed SLES and fatty acid micelles using molecular dynamics (MD) simulations. Micelle/water partition coefficients of neutral and charged fatty acids are then calculated using COSMOmic as well as a MD approach based on the potential of mean force (PMF) calculations performed using umbrella sampling (US). The combined US/PMF approach was performed with both the additive, non-polarizable CHARMM general force field (CGenFF) and the classical Drude polarizable force field. The partition coefficients for the neutral solutes are shown to be accurately calculated with the COSMOmic and additive CGenFF US/PMF approaches, while only the US/PMF approach with the Drude polarizable force field accurately calculated the experimental partition coefficient of the charged solute. These results indicate the utility of the Drude polarizable force field as a tool for the rational development of mixed micelles.

Topics: Fatty Acids; Micelles; Molecular Conformation; Molecular Dynamics Simulation; Sodium Dodecyl Sulfate; Solutions

Our surrounding environment, especially often-touched contaminated surfaces, plays an important role in the transmission of pathogens in society. The shortage of effective sanitizing fluids, however, became a global challenge quickly after the coronavirus disease-19 (COVID-19) outbreak in December 2019. In this study, we present the effect of surfactants on coronavirus (SARS-CoV-2) virucidal efficiency in sanitizing fluids. Sodium dodecylbenzenesulfonate (SDBS), sodium laureth sulfate (SLS), and two commercial dish soap and liquid hand soap were studied with the goal of evaporation rate reduction in sanitizing liquids to maximize surface contact time. Twelve fluids with different recipes composed of ethanol, isopropanol, SDBS, SLS, glycerin, and water of standardized hardness (WSH) were tested for their evaporation time and virucidal efficiency. Evaporation time increased by 17-63% when surfactant agents were added to the liquid. In addition, surfactant incorporation enhanced the virucidal efficiency between 15 and 27% according to the 4-field test in the EN 16615:2015 European Standard method. Most importantly, however, we found that surfactant addition provides a synergistic effect with alcohols to inactivate the SARS-CoV-2 virus. This study provides a simple, yet effective solution to improve the virucidal efficiency of commonly used sanitizers.

Topics: 2-Propanol; A549 Cells; Antiviral Agents; Benzenesulfonates; Betacoronavirus; Coronavirus Infections; COVID-19; Drug Synergism; Ethanol; Glycerol; Hand Sanitizers; Humans; Pandemics; Pneumonia, Viral; SARS-CoV-2; Soaps; Sodium Dodecyl Sulfate; Surface-Active Agents; Volatilization

The use of palladium (Pd) has grown in the last decades, commonly used in automotive catalytic converters, jewellery and dental restorations sectors. Both general and working population can be exposed to this metal, which may act as skin sensitizer. This study investigated in vitro palladium powders permeation through excised intact and damaged human skin using the Franz diffusion cell method and the effect of rapid skin decontamination using sodium laureth-sulphate. 1 mL of a 10 min sonicated suspension made of 2.5 g of Pd powder in 50 mL synthetic sweat at pH 4.5 and room temperature was applied to the outer surface of the skin membranes for 24 h. Pd permeation, assessed by ICP-MS, was higher when damaged skin was used (p = 0.03). Final flux permeation values and lag times were 0.02 ± 0.01 μg cm

Topics: Decontamination; Diffusion; Humans; Kinetics; Palladium; Permeability; Powders; Skin; Skin Absorption; Sodium Dodecyl Sulfate; Surface-Active Agents

Vibrational spectroscopy is a useful tool for analysis of skin properties and to confirm the penetration of drugs and other formulation compounds into the skin. In particular, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and confocal Raman spectroscopy (CRS) have been optimised for skin analysis. Despite an impressive amount of data on these techniques, a comparative methodological assessment for skin penetration monitoring of model substances is still amiss. Thus, in vitro skin penetration studies were conducted in parallel using the same porcine material and four model substances, namely sodium laureth sulfate (SLES), sodium dodecyl sulfate (SDS), sulfathiazole sodium (STZ) and dimethyl sulfoxide (DMSO). ATR-FTIR spectroscopy in combination with tape stripping and CRS were employed to evaluate the skin penetration of the applied substances. In addition, the skin hydration status or change in skin hydration after application was investigated. The results show that both methods provide valuable information on the skin penetration potential of applied substances. The penetration profiles determined by CRS or ATR-FTIR/tape stripping were comparable for all substances; a slow decrease in relative substance concentration was visible from the skin surface inwards within the stratum corneum (SC). In general, deeper penetration into the SC was observed with CRS, which may be related to the depth resolution of the employed device. However, when related to the respective total SC thickness of each experiment, the penetration depths determined by parallel CRS and ATR-FTIR analysis were in good agreement for all model substances. The observed order of the penetration depth was DMSO > SDS > SLES > STZ with both techniques. A decrease of the relative concentration to 10% of the maximum value was found approximately between 34 and 89% of total SC thickness. Summarising these findings, advantages and drawbacks of the two techniques for in vitro skin penetration studies are discussed.

Topics: Animals; Dimethyl Sulfoxide; In Vitro Techniques; Skin; Skin Absorption; Sodium Dodecyl Sulfate; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Sulfathiazole; Sulfathiazoles; Swine; Vibration

An influenza epidemic is still a problem despite the development of vaccines and anti-influenza drugs. Preventive measures such as handwashing are fundamental and important for counteracting influenza virus infection. In this study, we clarified the anti-influenza virus effects of surfactants, which are the main components of hand soaps for hand washing: potassium oleate (C18:1), sodium laureth sulfate (LES) and sodium lauryl sulfate (SDS). For a human influenza virus strain (H3N2), C18:1 reduced the infectivity by 4 logs or more, whereas LES and SDS reduced the infectivity by 1 log or less. Similar results were obtained when an avian influenza virus strain (H5N3) was used. The interaction between the surfactant and virus was then investigated by isothermal titration calorimetry. The LES-virus system showed a positive value of enthalpy changes (ΔH), meaning an exothermic interaction that indicated a hydrophobic interaction. In contrast, both the C18:1-virus system and the SDS-virus system showed negative values of ΔH, meaning an endothermic interaction that indicated an electrical interaction. The ΔH value of the C18:1-virus system was much higher than that of the SDS-virus system. A mixture of C18:1 and HA proteins similarly showed negative values of ΔH. These results indicate that influenza virus inactivation by a hydrophobic interaction of a surfactant with the viral envelope is insufficient to prevent infection, whereas inactivation by an electrical interaction of a surfactant with HA proteins is sufficient to prevent influenza virus infection.

Topics: Animals; Chick Embryo; Chickens; Dogs; Humans; Influenza A Virus, H3N2 Subtype; Influenza A Virus, H5N8 Subtype; Influenza in Birds; Influenza, Human; Madin Darby Canine Kidney Cells; Oleic Acid; Soaps; Sodium Dodecyl Sulfate; Virus Inactivation

Topics: Dermatitis, Atopic; Filaggrin Proteins; Humans; Intermediate Filament Proteins; Mutation; Skin; Sodium Dodecyl Sulfate

Combined ATR-FTIR (attenuated total reflection-Fourier transform infrared) spectroscopy and tape-stripping experiments in vitro on porcine ear skin were used to investigate the spatial distribution of different surfactants in the stratum corneum (SC). To reveal a possible connection between the size of the formed micelles and skin penetration, dynamic light-scattering measurements of the aqueous surfactant solutions were also taken. Compared to an alkyl polyglycoside and sucrose laurate, a deeper skin penetration of the anionic surfactants sodium dodecyl sulfate (SDS) und sodium lauryl ether sulfate (SLES) could be related to a smaller size of the formed micelles. Beside the differences in spatial distribution, a link between the physical presence of anionic surfactants in the SC and a decrease of skin hydration was found. Furthermore, the incorporation of SDS and SLES into the SC, even after a brief, consumer-orientated washing procedure with commercially available hair shampoos, was confirmed.

Topics: Adhesives; Animals; Caco-2 Cells; Cell Survival; Epidermis; Glucans; Hair Preparations; Humans; Micelles; Skin Absorption; Sodium Dodecyl Sulfate; Spectroscopy, Fourier Transform Infrared; Sucrose; Surface-Active Agents; Swine

Wormlike or threadlike structures with local cylindrical geometry are abundantly found in nature and technical products. A thorough structural characterization in the bulk for a whole ensemble, however, is difficult. The inherent semiordered nature of the tortuous large-scale structure and especially the quantification of branching renders an assessment difficult. In the present work we introduce a hybrid function expressing the scattering intensities for X-rays, neutrons, or light in the small-angle regime for this system. The function is termed "hybrid" because it employs terms from different approaches. The large-scale structure is described via a Guinier term as well as a concomitant power-law expression in momentum transfer q taken from the so-called unified function. The local cylindrical shape, however, is taken into account through a form factor for cylinders from rigid-body modeling. In principle, the latter form factor can be replaced by an expression for any other regular body so that the new hybrid function is a versatile tool for studying hierarchical structures assembled from uniform subunits. The appropriateness and capability of the new function for cylindrical structures is exemplified using the example of a wormlike micellar system.

Topics: Betaine; Micelles; Sodium Dodecyl Sulfate; Surface-Active Agents

Block co-polymer surfactants have been used for cleaning hydrogel medical devices that contact the body (e.g., contact lenses) because of their biocompatibility. This work examined the relationship between concentration and detergency of two non-ionic polymeric surfactants (Pluronic F127 and Triton X-100) for cleaning protein soil, with anionic surfactants (sodium dodecyl sulfate and sodium laureth sulfate) as positive controls. Surface plasmon resonance was used to quantify removal of simulated tear soil from self-assembled monolayer surfaces, and a microplate format was used to study the removal of fluorescently labeled soil proteins from contact lenses. While detergency increased as a function of concentration for anionic surfactants, it decreased with concentration for the two polymeric surfactants. The fact that the protein detergency of some non-ionic polymeric surfactants did not increase with concentration above the critical micelle concentration could have implications for optimizing the tradeoff between detergency and biocompatibility.

Topics: Biofouling; Contact Lenses; Detergents; Hydrogels; Lubricant Eye Drops; Octoxynol; Poloxamer; Sodium Dodecyl Sulfate; Solutions; Surface Plasmon Resonance; Surface-Active Agents

Sodium laureth sulphate (SLES) is an anionic detergent, which has been used globally for personal care products because of its mildness and good foaming ability. However, SLES is somewhat invasive and stimulatory to the skin, and many consumers with sensitive skin desire milder detergents for daily use skin cleansers. We enhanced the mildness of SLES by formulating it with sodium laureth carboxylate (AEC) and lauryl glucoside (LG).. In skin soak tests, 5% detergent solutions were applied to the forearms of 10 Japanese healthy volunteers for 30 min followed by washing with tap water once a day for 4 days. Twenty-four hours after the last treatment, cutaneous capacitance measurements and visual analyses were performed. In a controlled usage study, 16 Japanese healthy volunteers used the test body cleanser for 4 weeks. Assessment of efficacy and mildness was conducted prior to the start of the study and at the end of week 4 by cutaneous conductance, dermoscopic evaluation of the stratum corneum and visual assessment by a dermatologist.. In soak tests, cutaneous capacitance was significantly decreased on the soap-treated region and on the SLES-treated region. No significant decrease was identified on the SLES/AEC/LG-treated region with less induction of erythema or dryness. In the controlled usage study, no significant changes in cutaneous conductance or texture or damage of corneocytes on the forearm and lower thigh were found. However, visual assessment revealed a significant decrease in scaling and erythema on the lower thigh after 4 weeks of usage with an improvement of the discomfort of the consumer. The favourability rating of this formulated detergent in several questionnaire items was very good.. The newly formulated skin cleanser with the combination of anionic surfactants SLES and AEC and the non-ionic surfactant LG provides a mild surfactant with a satisfactory cleansing activity for body washing.

Topics: Carboxylic Acids; Erythema; Galvanic Skin Response; Glucosides; Humans; Japan; Male; Skin; Soaps; Sodium Dodecyl Sulfate; Statistics, Nonparametric; Surveys and Questionnaires; Water Loss, Insensible

The physical presence of surfactants in the skin is linked to their skin irritation potential. Combined ATR-FTIR spectroscopy and tape stripping experiments in vitro on porcine ear skin were used to investigate the spatial distribution of sodium lauryl ether sulfate (SLES) in the stratum corneum and to assess its effects on conformational order of stratum corneum intercellular lipids, secondary structure of keratin and skin hydration. It was possible to monitor the spatial distribution of SLES in the stratum corneum for the first time by subtracting spectra of untreated from treated skin samples and without the need of a perdeuterated form. This method of analysis was evaluated by addressing potential error sources such as differences in removed amounts of corneocytes and intra-individual changes in stratum corneum composition as a function of depth. The obtained results indicate a penetration of SLES into deep layers of the stratum corneum. Furthermore, SLES treatment led to significantly decreased skin hydration levels, whereas the secondary structure of keratin remained nearly unaffected. The reliability of this semi-quantitative method of analysis was confirmed by receiving a coefficient of determination of 0.9963 after making a correlation of deep depended absorbances of two different characteristic bands with different absorption coefficients.

Topics: Animals; Epidermis; In Vitro Techniques; Keratins; Lipids; Reproducibility of Results; Skin Absorption; Sodium Dodecyl Sulfate; Spectroscopy, Fourier Transform Infrared; Surface-Active Agents; Surgical Tape; Swine

Prion diseases are diagnosed by the detection of their proteinase K-resistant prion protein fragment (PrP(Sc)). Various biochemical protocols use different detergents for the tissue preparation. We found that the resistance of PrP(Sc) against proteinase K may vary strongly with the detergent used. In our study, we investigated the influence of the most commonly used detergents on eight different TSE agents derived from different species and distinct prion disease forms. For a high throughput we used a membrane adsorption assay to detect small amounts of prion aggregates, as well as Western blotting. Tissue lysates were prepared using DOC, SLS, SDS or Triton X-100 in different concentrations and these were digested with various amounts of proteinase K. Detergents are able to enhance or diminish the detectability of PrP(Sc) after proteinase K digestion. Depending on the kind of detergent, its concentration - but also on the host species that developed the TSE and the disease form or prion type - the detectability of PrP(Sc) can be very different. The results obtained here may be helpful during the development or improvement of a PrP(Sc) detection method and they point towards a detergent effect that can be additionally used for decontamination purposes. A plausible explanation for the detergent effects described in this article could be an interaction with the lipids associated with PrP(Sc) that may stabilize the aggregates.

Topics: Animals; Cattle; Deer; Deoxycholic Acid; Detergents; Endopeptidase K; Humans; Octoxynol; Prion Diseases; PrPSc Proteins; Sheep; Sodium Dodecyl Sulfate

Foam delivery technology (FDT) uses surfactant based foam to immobilize subsurface contaminants in situ. Where traditional approaches are impractical, FDT has the potential to overcome many of the technical challenges facing the remediation of contaminated deep vadose zone environments. However, little is known about the effects these reactive chemicals may have on microorganisms inhabiting the contaminated subsurface. In addition, there are currently no standard assays to assess microbial responses to subsurface remedial treatments while these agents are under development. The objective of this study was to develop a rapid laboratory assay to assess the potential growth inhibition and/or stimulation of microorganisms following exposure to candidate FDT components. Calcium polysulfide (CPS) and several surfactants (i.e. sodium laureth sulfate (SLES), sodium dodecyl sulfate (SDS), cocamidopropyl betaine (CAPB) and NINOL40-CO) have diverse chemistries and are candidate components of FDT. Shewanella oneidensis MR-1 cultures were exposed to a range of concentrations of these chemicals to determine the minimum bactericidal concentration (MBC) and the growth and viability potential of these components. Concentrations of SDS higher than 700 μM were toxic to S. oneidensis MR-1 growth over the course of four days of exposure. The relative acute toxicity order for these compounds was SDS >> CPS >> NINOL 40-CO>SLES≥CAPB. Dose dependent growth decreases (20-100mM) were observed in the CAPB and SLES treated cultures and both CPS and NINOL 40-CO were toxic at all concentrations tested (1.45-7.25 mM CPS). Both SLES (20-100mM) and SDS at lower concentrations (20-500 μM) were stimulatory to S. oneidensis MR-1 indicating a capacity to be used as a carbon source. These studies also identified potentially key component characteristics, such as precipitate formation and oxygen availability, which may prove valuable in assessing the response of subsurface microorganisms. This benchtop system provides a capability to assess adverse microbial-remediation responses and contributes to the development of in situ remedial chemistries before they are deployed in the field.

Topics: Calcium Compounds; Environmental Restoration and Remediation; Oxygen; Shewanella; Sodium Dodecyl Sulfate; Sulfides; Surface-Active Agents; Thiosulfates

The aim of this study was to evaluate the compaction behavior of a model two-component amorphous spray-dried dispersion system compared with the unprocessed excipients, using simulated rotary tablet press production conditions.. In this study, the stabilizing polymer, hypromellose acetate succinate (HPMCAS), was solubilized and spray dried with and without sodium lauryl sulfate (SLS). The impact of compression force and speed on the tabletting process was quantified by means of tablet tensile strength, compaction energy, and Heckel analysis.. Addition of the surfactant SLS, spray dried or as a physical mix, reduced the tablet strength. However, a lesser impact on the unprocessed excipients was observed in comparison with the spray-dried excipients. In the presence of 1% (w/w) SLS, tablets displayed a tendency to cap when compressed at higher speeds, supported by high elastic energy values indicating high uniaxial stress upon decompression. In the presence of 3% (w/w) SLS, tablets could not be produced at high speeds. Heckel analysis revealed a greater strain rate sensitivity of HPMCAS when spray dried in the presence of surfactant. Exposure of samples to a range of relative humidities before compaction had no effect on tablet strength.. This study has shown that spray drying of HPMCAS in the presence of a surfactant affects the compressibility of the material, resulting in decreased tablet strength, increased elastic deformation, and capping.

Topics: Compressive Strength; Excipients; Hypromellose Derivatives; Methylcellulose; Pressure; Sodium Dodecyl Sulfate; Succinic Acid; Tablets; Tensile Strength

Surfactants are commonly used as cleansing agents and yet there are concerns that they may also have a role in skin irritation. The lack of suitable methods for the quantitative and qualitative analysis of surfactant deposition on skin has hindered the in-depth investigation of such effects. Here, we report the application of reversed-phase liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) assays for two surfactants commonly used in consumer products, namely sodium lauryl ether sulfate (SLES) and laurylamidopropyl betaine (LAPB), to a baseline study aiming to assess deposition levels on human skin. The linearity of the assays was established at 3-20 ng, with coefficient of variation below 5%. The detection limits were 100 pg for LAPB and 1 ng for SLES; quantitation limits were 500 pg for LAPB and 2.5 ng for SLES. The baseline study was conducted using a panel of 40 healthy volunteers. Skin extract samples were taken in triplicate from forearms, using ethanol. SLES was detected on most volunteers, with 75% of them having SLES deposits in the range of 100-600 ng/cm(2). LAPB was detected on the skin of all volunteers with 85% of them having deposit levels within the concentration range of 1-100 ng/cm(2). These results demonstrate the extent to which commonly used surfactants remain on the skin during the day. The analytical methods reported here can be applied to the investigation of surfactants in relation to general skin condition and to the development and optimisation of new consumer wash products.

Topics: Adult; Betaine; Chromatography, Reverse-Phase; Drug Stability; Female; Forearm; Humans; Male; Sensitivity and Specificity; Skin; Skin Tests; Sodium Dodecyl Sulfate; Spectrometry, Mass, Electrospray Ionization; Statistics, Nonparametric; Surface-Active Agents; Tandem Mass Spectrometry

Sodium laureth sulfate is a member of a group of salts of sulfated ethoxylated alcohols, the safety of which was evaluated by the Cosmetic Ingredient Review (CIR) Expert Panel for use in cosmetics. Sodium and ammonium laureth sulfate have not evoked adverse responses in any toxicological testing. Sodium laureth sulfate was demonstrated to be a dermal and ocular irritant but not a sensitizer. The Expert Panel recognized that there are data gaps regarding use and concentration of these ingredients. However, the overall information available on the types of products in which these ingredients are used and at what concentrations indicates a pattern of use. The potential to produce irritation exists with these salts of sulfated ethoxylated alcohols, but in practice they are not regularly seen to be irritating because of the formulations in which they are used. These ingredients should be used only when they can be formulated to be nonirritating.

Topics: Alcohols; Cosmetics; Humans; Sodium Dodecyl Sulfate; Sulfates

A direct and effective method utilizing reversed-phase liquid chromatography combined with evaporative light scattering detection was developed to determine the relative ratio of different alkyl chain lengths, to quantify the average ethylene oxide (EO) level and to identify EO distribution in the presence of sodium laureth sulfates. A C8 bonded silica gel column and an acetonitrile-water gradient mobile phase containing ammonium acetate were used as the best stationary and mobile phase, respectively. The results were confirmed by nuclear magnetic resonance spectroscopy. The detection limit was 80 microg/mL and the calibration curve, i.e., the log-log plots (peak area vs. concentration), was linear in the working range of 80-4200 microg/mL with R(2) values of above 0.999 (in the case of 3 mol sodium laureth sulfates). Furthermore, the application of the chromatographic method to a commercial product without pretreatment was presented. The raw material was identified by fast atom bombardment mass spectrometry.

Topics: Chromatography, Liquid; Light; Mass Spectrometry; Nuclear Magnetic Resonance, Biomolecular; Scattering, Radiation; Sensitivity and Specificity; Sodium Dodecyl Sulfate

Biological processors are typically used in liquid- and gas-phase remediation as separately staged systems. This research presents a novel application of a biotrickling filter operated for simultaneous treatment of contaminants present in graywater and waste gas (ammonia and hydrogen sulfide). Liquid- and gas-phase contaminants were monitored via bioreactor influent/effluent samples over the course of a 300-day study. An oxygen-based bioassay was used to determine spatial location of the functional groups involved in the biodegradation of surfactants, dissolved hydrogen sulfide, and ammonium. Results indicated that a biotrickling filter is able to support the wide range of microbial species required to degrade the compounds found in graywater and waste gas, maintaining conversion efficiencies greater than 90% for parent surfactant compounds and waste gas constituents. These results provide evidence of an operational scheme that potentially reduces footprint size and cost of graywater/waste gas biotreatment.

Topics: Air Pollutants; Ammonia; Biodegradation, Environmental; Biological Assay; Filtration; Gases; Hydrogen Sulfide; Odorants; Sodium Dodecyl Sulfate; Surface-Active Agents; Time Factors; Waste Disposal, Fluid; Water Pollutants, Chemical

Oral drug delivery offers an attractive method of needle-free drug administration. Unfortunately, oral delivery is often hampered by the poor permeability of drugs across the intestinal epithelium. Although several single chemical permeation enhancers have been shown to alleviate permeability difficulties, this often occurs at the expense of safety. This in vitro study demonstrates the use of binary and ternary combinations of permeation enhancers to create synergistic enhancer formulations (SEFs) that offer a high level of potency while inducing very little toxicity in Caco-2 cells. Although relatively rare in the explored formulation space, SEFs were abundant enough to significantly increase the repertoire of permeation enhancers that are safe and effective in vitro. The most promising enhancers from the binary study led to easily identifiable ternary SEFs, thus increasing the efficiency of the discovery process. Some of the best performers of the study included binary combinations of hexylamine and chembetaine and ternary combinations of sodium laureth sulfate, decyltrimethyl ammonium bromide, and chembetaine, all at a total concentration of 0.1% (w/v). Furthermore, several SEFs were shown to be capable of increasing mannitol and 70 kDa dextran permeability across Caco-2 monolayers 15- and 8-fold, respectively. These results encourage further exploration of several leading formulations for in vivo applications in oral drug delivery.

Topics: Adjuvants, Pharmaceutic; Administration, Oral; Amines; Bicyclic Monoterpenes; Caco-2 Cells; Cell Membrane Permeability; Cell Survival; Cholic Acids; Decanoic Acids; Dextrans; Drug Combinations; Drug Synergism; Electric Impedance; Epithelial Cells; Humans; Intestinal Absorption; Intestinal Mucosa; Mannitol; Pyrrolidinones; Quaternary Ammonium Compounds; Sarcosine; Sodium Dodecyl Sulfate; Surface-Active Agents; Terpenes

Topics: Anti-HIV Agents; Drug Combinations; Hydrogen-Ion Concentration; Sodium Dodecyl Sulfate; Solubility

The cutaneous reaction to detergents follows distinct kinetic rules: the duration of application and the irritant concentration are of major importance. The aim of this study was to evaluate the differences in kinetics of skin reaction between the standard irritant sodium lauryl sulfate (SLS), and 2 modern detergents: sodium laureth sulfate (SLES) and alkyl polyglucoside (APG). We performed patch testing with SLS and SLES (or APG) at different concentrations (0.125, 0.25, 0.5, 1.0 and 2.0%) and with different exposure times (6, 12 and 24 h). Evaluation was conducted by measurement of transepidermal water loss (TEWL) and laser Doppler flowmetry (LD) 24 h, 7 and 10 days after patch removal. We found a pronounced reaction to SLS, and a far milder one to SLES. Even at the highest concentration the skin reaction to APG was hard to detect. During the regeneration period (day 3-10) SLS showed even at day 10 an increased TEWL at all concentrations tested. The irritation due to SLES was convincingly detectable only up to day 7, whereas the APG-tested skin areas showed no significant reaction even at day 3. These results demonstrate the improvement in reduction of skin irritation achieved by development of novel detergents.

Topics: Adolescent; Adult; Dermatitis, Allergic Contact; Detergents; Dose-Response Relationship, Drug; Female; Glucosides; Humans; Irritants; Laser-Doppler Flowmetry; Male; Middle Aged; Patch Tests; Reference Values; Sodium Dodecyl Sulfate; Water Loss, Insensible