Cocamidopropyl Research Articles

Contact Dermatitis Associated With Hair Care Products: A Retrospective Analysis of the North American Contact Dermatitis Group Data, 2001-2016.

Hair care products (HCPs) may cause both allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD). The aims of the study were to determine the prevalence of HCP-associated ICD/ACD and to characterize relevant allergens. This study is a retrospective analysis of North American Contact Dermatitis Group (NACDG) patch test data, 2001-2016. Of 38,775 patients tested, 3481 (9.0%) had positive patch test reactions associated with HCPs. The HCP-positive patients were significantly more likely to be female (79.9% vs 66.0%) and/or have primary sites of dermatitis on the face (32.0% vs 27.8%) or scalp (15.4% vs 2.2%) compared with the HCP-negative patients (P < 0.0001). Of 4908 HCP-associated positive patch test reactions, 86.9% (n = 4263) were due to allergens on the NACDG screening series; p-phenylenediamine (35.8%), methylisothiazolinone (9.7%), methylchloroisothiazolinone/methylisothiazolinone (8.7%), and cocamidopropyl betaine (5.9%) were the most frequent. Most reactions (87.7%, 3736/4263) were currently clinically relevant. The most common job associated with 366 occupationally related NACDG HCP-associated allergens was hairdresser/cosmetologist (71.9%). Two hundred eighty-two patients (0.7%) had ICD associated with HCPs. Shampoo/conditioners were the most frequent source of NACDG HCP-associated reactions (47.3%) and HCP-associated ICD (45.0%). Of the HCP-positive patients, 18.5% had HCP reactions to allergens not on the NACDG screening series, underscoring the importance of patch testing to expanded series in patients suspected of HCP allergy.

Mesoporous Silica Nanoparticles as a System for Ciprofloxacin Drug Delivery; Kinetic of Adsorption and Releasing

Mesoporous silica (MPS) nanoparticle was prepared as carriers for drug delivery systems by sol–gel method from sodium silicate as inexpensive precursor of silica and Cocamidopropyl betaine (CABP) as template. The silica particles were characterized by SEM, TEM, AFM, XRD, and N2adsorption–desorption isotherms. The results show that the MPS particle in the nanorange (40-80 nm ) with average diameter equal to 62.15 nm has rods particle morphology, specific surface area is 1096.122 m2/g, pore volume 0.900 cm3/g, with average pore diameter 2.902 nm, which can serve as efficient carriers for drugs. The adsorption kinetic of Ciprofloxacin (CIP) drug was studied and the data were analyzed and found to match well with pseudo-first order kinetic model. The CIP drug-loaded mesoporous silica (CIP-mSiO2) nanoparticles has capacity of about 16.3 mg drug/ mg mSiO2 were achieved, and capable of releasing 26% and 98.6% of their drug content after 90 min in water and PBS solution(pH,7.4) respectively. In-vitro controlled release studies of CIP in Simulated Body Fluid were carried out under stirring conditions. A study on release kinetics and mechanism using Koresmeyer-Pepps model, first order kinetic, and kopcha model shows that the Korsmeyer-Peppas and Kopcha models, both conform more closely to the release data.

Investigation of the interactions of cationic guar with human hair by electrokinetic analysis.

ObjectiveCationic guar is an important polysaccharide used as a hair conditioning agent in personal care products. In this article, we report streaming potential data demonstrating its behaviour as it interacts electrostatically with hair. Several cationic guar variants with different molecular weights (MWs) and charge densities (CDs) were examined.MethodsAll experiments were carried out with a custom‐designed streaming potential instrument so that in situ, real‐time data were monitored during the treatment of a hair plug with aqueous solutions of cationic guar and subsequent treatment with anionic surfactants—sodium laureth sulfate (SLES) and cocamidopropyl betaine (CAPB)—commonly found in contemporary shampoo formulations.ResultsThe MW of the cationic guar variants plays an integral role in determining the thickness of the adsorbed polymer layer on the hair surface while CD influences the zeta potential. Data were also generated for the treatment of hair with a cationic flexible polymer (polyquaternium‐28) and cationic conditioning surfactant (behentrimonium chloride) to provide a frame of reference. The deposition behaviour on hair of high MW cationic guar variants is distinct from these conventional molecules in terms of its electrokinetic properties. We also examined the electrokinetic behaviour of cationic guar on hair types from different racial backgrounds. While the cationic guar treatment yielded similar results for the different hair types, anionic surfactant treatment resulted in quicker sorption and desorption from African, European 65% grey, and Mulatto hair as compared to Chinese, European dark brown, and Indian hair.ConclusionWe introduce an in situ technique for measuring the dynamic sorption/desorption of charged molecules on the surface of human hair. Evaluation of a series of cationic guar species revealed varying behaviour depending on the MW and CD of the polysaccharide. Our data also demonstrate differences in the desorption properties of typical shampoo surfactants for hair from diverse racial backgrounds.

Study on Interaction of Carboxylic Acid Gemini Surfactant with Cocamidopropyl Betaine in Aqueous Solution

Abstract The interaction of carboxylic acid gemini surfactant 4,8-didodecyl-3,9-dioxo-6-hydroxy-4,8-diaza-1,11-undecanedicarboxylic acid (CGS12) with amphoteric surfactant cocamidopropyl betaine (CAPB) at 258C and pH 7.0 has been investigated using pH titration, surface tension, dynamic light scattering (DLS) and cryogenic transmission electron microscopy (Cryo-TEM) measurements. The pH titration results show that CGS12 exhibits anionic surfactant properties and CAPB exists as a zwitterionic form at pH 7.0. The surface tension results show that the critical micelle concentration (CMC) values of the CAPB/CGS12 mixture are low, and basically exhibit a decreasing trend with decreasing molar ratio of CAPB (XCAPB). The variation of the CMC of the mixture reveals that the mixing is close to ideal. The DLS results indicate that the CAPB/ CGS12 mixture mainly forms the larger aggregates with the hydrate radii approximately 70-145 nm at various XCAPB. The Cryo-TEM images further demonstrate the CAPB/CGS12 mixtures mainly form vesicles. The results indicate that the aggregate size and microstructure of the mixture change little with the variation of XCAPB.

Drag Reduction in the Flow of Aqueous Solutions of a Mixture of Cocamidopropyl Betaine and Cocamide DEA

The study presents results of rheological tests and measurements of pressure drops occurring during the flow of aqueous solutions of a mixture of drag reducing surfactants: cocamidopropyl betaine (CAPB, zwitterionic surfactant) and cocamide DEA (nonionic surfactant) through straight pipes. Tests were carried out at different CAPB/DEA weight ratios and different total concentrations of surfactants in the solution. Rheological measurements demonstrate the formation of a shear-induced structure (SIS) in the temperature range below 10 °C, which provides evidence for the presence of wormlike micelles in CAPB/DEA solutions. Drag reduction was observed during the flow of CAPB/DEA solutions in the temperature range from 3 to 45 °C, however, above 25 °C the degree of drag reduction was markedly decreased. The lower temperature limit at which drag reduction occurs depends on the CAPB and DEA weight ratio in the solution. In the range of higher temperatures, during the flow of CAPB/DEA solutions (similarly to flexible-chain polymer solutions) the onset of drag reduction is noted above a certain critical value of the Rec,0 number, whose value depends on the temperature of the solution, diameter of the pipe and the weight ratio of surfactants. At the same time, the critical value of wall shear stress τw,c0 corresponding to the critical value of Rec,0 is approximately independent of pipe diameter. The critical value of the Rec,0 number has been linked to the clouding of CAPB/DEA solutions.

Enzymatic biofilm destabilisation to support mechanical cleansing of inserted dental implant surfaces: an in-vitro pilot study

Peri-implantitis is caused by microbial contamination and biofilm formation on the implant surface. To achieve re-osseointegration, the microbes must be completely removed from the surface. Adjunctive to mechanical cleaning, chemical treatment with enzymes or other substances could optimise the treatment outcome. Therefore, we investigated the efficacy of different enzymes, a surfactant, and a chelator in destabilising dental polymicrobial biofilm. The biofilm destabilising effect of the glycosidases α-amylase, dextranase, DispersinB®, and lysozyme, as well as the proteinase subtilisin A, and the nuclease Benzonase®, the chelator EDTA, and the surfactant cocamidopropyl betaine were investigated on biofilms, inoculated with plaque on rough titanium discs. The test and the control solutions were incubated for 15 min at 36 °C on biofilms, and loosened biofilm mass was removed by shear stress with a shaker. Fluorescence-stained biofilms were microscopically analysed. Acceptable cell tolerability concentrations of test substances were determined by the MTT (tetrazolium dye) assay on the MG-63 cell line. A statistically significant biofilm destabilising effect of 10% was shown with lysozyme (2500 µg/ml).

Impact of polyelectrolyte-surfactant interactions on the rheology and wet lubrication performance of conditioning shampoo.

The purpose of this study is to understand the impact of the cationic polymer merquat on the rheological behavior of the mixed surfactant system of sodium lauryl ether sulfate (SLES) and cocamidopropyl betaine (CapB) as well as the impact of varying formulation conditions on the wet lubrication performance of the SLES-CapB-Merquat system. Rotation mechanical Rheometry was used to study the rheological response of the SLES-CapB-Merquat systems. Frequency sweeps were conducted to analyze the rheological properties of the system at low frequency ranges and bulk viscosity of the system was studied at high shear rates at varying salt and polymer concentrations. Wet combing tests and hair friction tests were run on the Dia-stron MTT175 flexible miniature tensile tester in order to evaluate the conditioning effects of the different formulations. The SLES-CapB system on its own exhibits very little viscosity. The bulk rheology results show that the addition of Merquat enhances the viscosity and viscoelastic properties of the SLES-CapB-Merquat system indicating the presence of electrostatic interactions between the surfactant and polyelectrolyte. Addition of salt had a significant impact on the system's rheological response due to the charge screening effect of salt. Wet combing force data indicate that the charged polyelectrolyte binds to the hair substrate resulting in reduced combing force values after the product was applied. The addition of silicone oil to the formulation seemed to greatly enhance the conditioning effect of the formulation. The charge interactions between SLES, CapB and Merquat results in the formation of an integrated gel like network, thus building the viscosity of the system. Variation of parameters like polymer and salt concentration has the potential to modify the bulk rheological properties and consequently the wet lubrication properties of the system.

Antibacterial and antibiofilm activities of cinnamon essential oil nanoemulsion against multi-species oral biofilms

Cinnamon essential oil (CEO) has antibacterial properties, but its ability to suppress the formation of multi-species oral biofilms has not been fully elucidated. This study evaluated the antibacterial and antibiofilm activities of cinnamon essential oil nanoemulsion (CEON) against oral biofilms formed using a microcosm biofilm model. The biofilms were formed on bovine enamel specimens over a 7-day period, during which all specimens were treated with one of three solutions: 5% CEON (n = 35), 0.5% cocamidopropyl betaine (n = 35), or 0.12% chlorhexidine gluconate (CHX; n = 35). Antibacterial and antibiofilm activities were determined by the red/green ratios (R/G values) of 7-day-old mature biofilms photographed with quantitative light-induced fluorescence-digital, the number of aciduric bacterial colony-forming units (CFUs) within each biofilm, and the absorbance of bacterial suspensions. One-way and repeated-measures analysis of variance were performed to compare differences among the three solutions. R/G values were lowest in the 0.12% CHX group, but not significantly differ from the 5% CEON group. The number of CFUs and absorbance were lowest in the 5% CEON group. This study showed that nanoemulsified CEO inhibited the maturation of multi-species oral biofilms and the growth of oral microorganisms in biofilms, including aciduric bacteria that cause dental caries.

Application of Newly Synthesized Sulfobetaine Based on Sweet Almond Oil in Bath Liquids for Sensitive Skin

Abstract Three formulations for bath liquids were developed, differing in the type of amphoteric surfactant applied. The formulations used Cocamidopropyl Betaine, Cocamidpropyl Hydroxide and newly synthesized sulfobetaine based on sweet almond oil (Oleicamidopropyl Sultaine). The molecular structure of the surfactant used in the manufactured formulations has a negatively charged sulfonate group and a positively charged quaternary nitrogen atom. Such molecular structures suggest that the functional properties of this substance are mild. Based on the research, it was found that the bath fluid containing the newly synthesized sulfobetaine based on sweet almond oil had the lowest zein number, the lowest pH increase of bovine albumin solution and the lowest ability to emulsify fatty dirt. This indicates a very low irritant effect of the tested bath liquid.

Randomised study of intra-oral kinetics of fluoride-containing toothpastes

ObjectivesThis randomised, controlled, analyst blind, crossover study aimed to evaluate and compare salivary fluoride and calcium ion concentration over 60 min following brushing with an assigned treatment and following an orange juice (OJ) or deionised (DI) water rinse 60 min post-brushing. MethodsStudy treatments, both containing 1150 ppm fluoride as NaF and 5% w/w KNO3, were the Test (including 1.2 % w/w cocamidopropyl betaine) and Comparator (including tetrasodium pyrophosphate and sodium lauryl sulphate) toothpastes. Twenty nine participants were randomised to treatment. ResultsA sharp increase in salivary fluoride ion concentration immediately post-brushing with either toothpaste decreased over time. Fluoride concentration following Test toothpaste use was numerically higher than the Comparator at all timepoints, with a significant difference from 10 min post-brushing (p < .05). Following the 60 min rinse, there were no significant differences between the Test or Comparator + OJ groups in salivary fluoride concentration but the Test + DI water group was significantly lower than Test (p < .001) or Comparator (p < .001) + OJ groups. A reduction in salivary calcium ion concentration was seen immediately post-brushing and after the OJ rinse with both toothpastes. Significant differences were observed in favour of the Test toothpaste at all timepoints (p < .05) and for Test and Comparator + OJ group (p < .001) compared with Test + DI water rinse. Both treatments were generally well-tolerated. ConclusionsThis study demonstrated that toothpaste formulations with identical declared fluoride concentrations and the same fluoride source give rise to differing intraoral fluoride concentrations over time, which are potentially related to different formulation excipient effects. Clinical significanceBy understanding the interaction of toothpaste formulation excipients in the oral environment, formulations can be developed that maximise retention of fluoride in the oral environment.

Study on preparation and properties of mineral surfactant – microbial dust suppressant

In order to solve the problem of coal dust pollution and further improve the dust suppression performance of microbial dust suppressant, a surfactant-microbial dust suppressant is prepared through the addition of surfactant to microbial dust suppressant. The optimal formula is as follows: mineralized bacteria (OD600 ≈ 1.6) cultivated for 48 h, 0.5 mol/L of cementing fluid and 0.08% cocamidopropyl betaine (CAB). Compared with microbial dust suppressant, surfactant (CAB)-microbial dust suppressant has better anti-evaporation and wind erosion resistance. Molecular dynamic simulations and contact angle experiments verified the improvement of the wettability of microbial dust suppressants by surfactants. XRD and SEM-EDS results show that calcium carbonate precipitates in coal dust treated with CAB-microbial dust suppressant, which can consolidate the coal dust particles into a whole. In summary, the addition of surfactants improves the dust suppression efficiency of microbial dust suppressants.

Investigating the effect of a simplified perfume accord and dilution on the formation of mixed-surfactant microemulsions.

The phase analysis of a mixed surfactant system is much more complex than that for a single surfactant system. The addition of fragrance further enhances the complexity of such colloidal systems. The wide variation in structure and log P values of perfume raw materials influence its partitioning into the micellar phase. Herein, we have created a simplified perfume accord consisting of three perfume raw materials (3-PRM) and investigated its loading within a mixed-surfactant system consisting of sodium trideceth-2 sulfate/ST2S and cocamidopropyl betaine/CAPB, along with citric acid and dipropylene glycol. We performed a systematic phase diagram analysis and identified the isotropic phases and compositions of interest. Select compositions from the phase diagram were further investigated to learn how the geometry of the surfactant self-assembly and the localization of the PRMs within the surfactant self-assembly changed when water or perfume is added. A combined small-angle neutron scattering/SANS and NMR methodology was used to identify variation in colloidal domains and positioning of perfume molecules at varying dilutions/rinse off scenarios. The results obtained were utilized to better distinguish distorted micelles from true microemulsions. The systematic investigation here provides a fundamental understanding about the self-assembly, encapsulation and perfume release from a commercially relevant mixed surfactant system.

Optimizing interactions between soluble silk fibroin and capryl glucoside for design of a natural and high-performance co-surfactant system.

Because of the strong consumer driver towards more natural or higher sustainability cosmetic products, silk fibroin was evaluated to help develop a formulation with natural and effective ingredients for personal care. In order to exploit the physical properties of silk fibroin, it was evaluated to maximize the surfactant properties of other commercial ingredients to lower surface tension and build up viscosity. A synergistic effect was seen between silk fibroin and capryl glucoside, a sugar surfactant which exhibited a natural and effective co-surfactant system. This system demonstrated better surface tension properties than sodium laureth sulphate (SLES), cocamidopropyl betaine (CAPB), rhamnolipids and sophorolipids, which led to greater foamability and cleansing properties. This system proved to also be compatible with polysaccharide viscosity modifiers to enhance the viscosity of the system. The present study comprises a systematic exploration of natural formulation development of silk proteins and other natural ingredients, which result in high performance such as enhanced foam quality, foam stability and enhanced sebum removal. All of these properties are desirable and may utilized when formulating cleaners and shampoos. A force tensiometer, Attension Sigma 701, was used to measure the surface tension of the silk protein and its various combinations with biosurfactants and biopolymers. To measure bulk rheology, a traditional mechanical rheometer TA DHR-3 was utilized. Foaming tests and sebum removal assays were also carried out to evaluate the performance of the samples. Silk fibroin was evaluated to maximize the surfactant properties of other commercial systems to develop a formulation containing natural and effective ingredients for personal care. The surface activity of silk proteins was seen to be synergistically enhanced in the presence of sugar surfactants such as capryl glucoside, resulting in a surface tension at the air-water interface which is lower than either that of pure silk fibroin or pure capryl glucoside. This surface tension value is additionally lower than that obtained from currently utilized synthetic surfactants like sodium laureth sulphate (SLES) and cocamidopropyl betaine (CAPB). This reduction in surface tension demonstrated greater foamability and cleansing properties than that of the commercial systems. The very low surface tension values obtained through combinations of silk proteins and glucoside resulted in a natural and effective co-surfactant system by forming high-quality stable foams and enhancing sebum removal. The rheological performance of the silk proteins was impacted through microstructure modifications as a result of interactions with biopolymers like carrageenan. This shows that this system is compatible with polysaccharide viscosity modifiers. It was observed that both the flow curve and the absolute viscosity values were significantly impacted in the presence of carrageenan, with higher viscosity generation and significant non-Newtonian/shear thinning behaviour evolution. These results indicate that the silk fibroin can be utilized to build a high-performance natural product and significantly enhance the performance of other natural/sustainable cosmetic formulations through building synergistic interactions with other natural ingredients such as sugar surfactants and biopolymers. These properties exhibited by this system are all desirable for cleansers and shampoos within the cosmetic industry. Silk fibroin in combination with capryl glucoside outperforms other commercial surfactants that are commonly used in the industry because of its surface-active behaviour and synergy. This system is then enhanced further with polysaccharide rheological modifiers, carrageen and xanthan gum to help build up viscosity. The complex mixture of silk fibroin, sugar surfactant and biopolymer results in a formulation that is all natural, while still having high performance by achieving great foamability and enhanced sebum removal. The mixture can further be used to formulate a fully natural product such as a cleanser or shampoo while still having the same or greater effectiveness as synthetic surfactants and ingredients typically used in cosmetic formulations.

Determining threadlike micelle lengths from rheometry

We show that the average length ⟨L⟩ of threadlike micelles in surfactant solutions predicted by fitting results of a mesoscopic simulation, the “pointer algorithm,” to experimental G′(ω), G″(ω) data, is longer than, and more accurate than, that from a scaling law that equates ⟨L⟩/le to the modulus ratio G0/Gmin′′. Here, G0 is the plateau modulus, Gmin′′ is obtained at the local minimum in G″, and le is the entanglement length. The accuracy of the pointer algorithm is supported by the agreement of its predictions with results from a recent application of the slip-spring simulation method to threadlike micelles. Improved fits of the pointer algorithm to the slip-spring results are obtained for weakly entangled micelles (with an average number of entanglements of Z &amp;lt; 15) if the full spectrum of Rouse modes is included in the description rather than just the high-frequency modes included in an earlier version. For sodium laureth-1 sulfate and cocamidopropyl betaine in NaCl solutions, we find scaling relations for micelle length, the plateau modulus, and the persistence length that are in rough agreement with the predictions of mean field theory and with the modified scaling relation in which ⟨L⟩/le is raised to the 0.82 power, rather than unity, that we recommend as an improvement to the original scaling law.

Surfactant-silica nanoparticle stabilized N2-foam flooding: A mechanistic study on the effect of surfactant type and temperature

The application of nitrogen foam for enhanced oil recovery (EOR) purposes has grabbed the attention of many researchers. With this in view, the main objective of this paper is to design a promising foaming agent by evaluating the influence of silica (SiO2) nanoparticles in combination with three different surfactant-stabilized N2-foams at various salinities and temperatures. Therefore, precise experiments were conducted to investigate the stability of produced foam in the presence of cocamido propyl betaine (CAPB), linear alkylbenzene sulphonic acid (LABSA), and cetyltrimethylammonium bromide (CTAB) as amphoteric, anionic, and cationic surfactants, respectively, and N2 as the gaseous phase. Firstly, foam stability tests were performed, and the results revealed that using the CAPB solution as the aqueous phase for N2-foam generation leads to higher foam stability compared to the LABSA and CTAB surfactants. Secondly, the effects of SiO2 nanoparticles and NaCl on the stability of the generated foams were investigated through the foam half-life time measurements. The outcomes demonstrated that a combination of CAPB (0.05 wt%) + SiO2 (0.1 wt%) + NaCl (5.0 wt%) could form almost 2.28 and 3.15 times more stable foams, as compared to the similar conditions in the presence of CTAB and LABSA surfactants, respectively. Investigations on the effects of temperature on foam revealed that the superiority of the CAPB in generating more stable foams (compared to LABSA and CTAB) continues to 50 °C, and then, as the temperature increases to 70 °C, CTAB surfactant surpasses the CAPB and LABSA surfactants in stabilizing the N2-foams. Furthermore, bulk foam stability tests in the presence of oil was conducted and the results showed that the CAPB surfactant -with the lowest hydrophilic-lipophilic balance (HLB)- was more damaged, as compared to the other used surfactants. The results of foam flooding experiments into three sister carbonate core samples showed an increase of 28.6, 32.1, and 41.0% in ultimate oil recovery by using LABSA, CTAB, and CAPB in combination with SiO2 as the aqueous phase.

In Situ Nanostructural Analysis of Concentrated Wormlike Micellar Fluids Comprising Sodium Laureth Sulfate and Cocamidopropyl Betaine Using Small-Angle Neutron Scattering.

Concentrated wormlike micellar fluids form the basis for a vast array of formulated products, from liquid soaps and shampoos to drag reduction and drilling fluids. Typically, these systems are analyzed using bulk rheological measurements to determine their flow properties and cryo-microscopy to detect their nanostructure. Small-angle neutron scattering provides an opportunity to directly and nonperturbatively analyze nanostructure in situ but is complicated for concentrated systems by correlations from interparticle volume exclusion. Here, we use small-angle and ultra-small-angle neutron scattering to probe directly for the first time the nanostructure of concentrated wormlike micellar fluids composed of the widely used surfactant pair sodium laureth sulfate and cocamidopropyl betaine in aqueous electrolytes. Obtained data are analyzed using different approaches to determine scattering contributions from the wormlike particles themselves and interactions between them. It is found that approximating worms as locally rigid cylinders offers some insight into their aggregation dimensions at short length scales, and both volume exclusion and screened Coulombic interaction potentials describe interactions reasonably well. Using the semi-empirical polymer reference interaction site model (PRISM) gives excellent agreement with observed scattering, and physical insight obtained using this approach is discussed in detail. A drawback of this method is the significant complexity in coding the model in order to fit data, so to facilitate this for future researchers, we provide with this paper a fully operational, open-source code to utilize this model.

Is there a role of toothpastes in the development of recurrent aphthous stomatitis? A prospective controlled clinical trial with skin patch testing

The oral mucosa is exposed to a large number of antigenic agents contained in toothpastes. These agents are reported to stimulate recurrent aphthous stomatitis (RAS) pathogenesis, and toothpastes that do not contain probable allergenic substances reduced the number and frequency of aphthous ulcers. We aimed to determine whether the skin patch test (SPT) can be used to determine if toothpaste allergens play a role in the etiology of RAS. Sixty-three patients with RAS and 47 healthy volunteers were skin patch tested with sodium lauryl sulfate, cocamidopropyl betaine, propylene glycol, aluminum chloride hexahydrate, menthol, triclosan, and titanium dioxide, which are present in most of the toothpastes. Fisher's exact test and the Yates chi-square test were used to compare categorical variables and patch test results between 2 groups. The SPT was positive in 8 (22.2%) patients with RAS and 11 (23.4%) control subjects, and the difference between the groups was not statistically significant (P < .05). Sodium lauryl sulfate, titanium dioxide, and menthol were the most common positive allergens in both groups. Allergens in toothpastes did not appear to stimulate the formation of RAS. However, in order to determine a clearer relationship, a study in a larger patient series employing intraoral patch testing with more toothpaste ingredients is suggested.

Development and evaluation of shampoo products based on coconut oil source from Ben Tre Province (Vietnam)

In order to enhance the use of coconut oil through its application in personal care products, shampoos formulated with simple soap act as the leading detergent with a 20% content and ingredients other commercial components such as Sodium Lauryl Ether Sulfate, Plantacare 2000, Glycerin, Cocamidopropyl Betaine, etc. A combination of 20% crude soap and a synthetic active substance synthesizing sodium lauryl ether sulfate (SLES) 5% make up the excellent shampoo recipe with cleansing feature. Ingredients of complementary detergents, moisturizers, and smoothing softeners are supplemented with appropriate levels to improve raw soap’s disadvantages. Foamability and foam durability are selected targets to examine the influence of ingredients in the formula. The sensory elements of the product reach the set goals with an average evaluation score of about 4/5. Thereby, shampoo products penetrate the cosmetic market and attract many consumers in the future.

The Relationship between Wormlike Micelle Scission Free Energy and Micellar Composition: The Case of Sodium Lauryl Ether Sulfate and Cocamidopropyl Betaine

The scission energy is the difference in free energy between two hemispherical caps and the cylindrical region of a wormlike micelle. This energy difference determines the logarithm of the average micelle length, which affects several macroscopic properties such as the viscosity of viscoelastic fluids. Here we use a recently published method by Wang et al (Langmuir 2018 34 1564-1573) to directly calculate the scission energy of micelles composed of monodisperse sodium laurylethersulphate (SLESnEO), an anionic surfactant. Utilising dissipative particle dynamics (DPD), we perform a systematic study varying the number of ethoxyl groups (n) and salt concentration. The scission energy increases with increasing salt concentration, indicating that the formation of longer micelles is favoured. We attribute this to the increased charge screening that reduces the repulsion between head groups. However, the scission energy decreases with increasing number of ethoxyl groups as the flexibility of the head group increases and the sodium ion becomes less tightly bound to the head group. We then extend the analysis to look at the effect of a common co-surfactant, cocamidopropyl betaine (CAPB) and find that its addition stabilises wormlike micelles at a lower salt concentration.

Suspension Culture of Erythrocytes in the Assessment of the Detergent Functional Component Toxicity Level

Background. The study is devoted to the assessment of the cytotoxic properties of various surfactants by a method that is highly sensitive to identification of their negative effect on living mammalian cells.Objective. The aim of the work is to carry out a comparative assessment of modern surfactants in terms of the degree of manifestation of cytotoxic properties.Methods. The study of 10 surfactants was carried out with a new method for assessing the cytotoxic effect of agents based on surfactants, which is a modification of The RBC Hemolysis Test and Hemoglobin Denaturation Test. This method calculates the integral cytotoxicity index, which takes into account the data obtained by two tests. The following indicators were determined in the work: the percentage of hemoglobin denaturation in a 1% surfactant solution (D, %), the concentration of the surfactant solution at which hemolysis of 50% erythrocytes occurs (H50,%), and the cytotoxicity coefficient (Cc, conv. un.) of surfactants which is calculated by the formula Cc = H50/D×10000.Results. According to the integral Cc indicator, the studied surfactants can be ranked according to the degree of toxicity reduction in the following order: sodium lauryl sulfate (0.09) – sodium laurate sulfate (0.13) – cocamidopropyl betaine (0.27) – sodium salt of polyethoxysulfosuccinate (0.27) – alkyldimethyl betaine (1.07) – disodium cocoamphodiacetate (1.99) – sodium salt n-palmethylglutamic acid (3.22) – cocoglucoside (27.86). Diethanolamides of coconut oil fatty acids and polyquaternium 7 in the studied concentration range (up to 1%) did not show denaturation properties.Conclusions. Studies have shown that surfactants significantly differ from each other by the level of the damaging effect, the most aggressive components were anionic and amphoteric surfactants, nonionic surfactants have a significantly lower cytotoxic effect (10 times). The results obtained should be taken into account when creating soft agents based on surfactants.