LAURYL GLUCOSIDE

Allergens are periodically added to the European Baseline Series (EBS) to audit their value in consecutive patch testing. To present results of audit allergens tested in consecutive patients in 54 departments in 13 European countries during 2021 and 2022. Anonymized or pseudonymized individual data, and partly aggregated data on patch test rest results and their clinical relevance were prospectively collected and centrally pooled and analyzed. In 2021 and 2022, 18 832 patients were patch tested with the EBS, and 2860 with the TRUE Test baseline series (supplemented with some missing EBS allergens). Of these patients, 17 359 were additionally tested with one or more of the 19 audit allergen preparations examined. Apart from the terpene hydroperoxides (OOH) which yielded the highest numbers of positive patch test reactions (linalool-OOH 1% pet.: 7.65 (7.09%-8.23%) [95% CI] and limonene-OOH 0.3% pet. 6.78 (6.26%-7.32%)), positive reactions were most often seen to benzisothiazolinone (3.71 (3.3%-4.15%)), sodium metabisulfite (3.49 (3.14%-3.88%)), Evernia furfuracea (tree moss, 1.79 (1.4%-2.26%)), and decyl and lauryl glucoside, at 1.49 (1.25%-1.76%) and 1.26 (1.05%-1.51%), respectively. The other allergens yielded around 1% or fewer positive patch test reactions. Clinical relevance varied, with Evernia furfuracea, 2-bromo-2-nitropropane-1,3-diol and terpene hydroperoxides considered relevant in more than 2/3 cases, while for other frequent sensitizers benzisothiazolinone and sodium metabisulfite, relevance could be confirmed in half of the cases or less often. The current results, along with other published data, will serve to inform decisions concerning possible revision of the EBS, considering frequency of positive reactions, their clinical relevance and the overall reaction profile of each of the allergens.

Alkyl glucosides are surfactants commonly found in cosmetics and household products. However, data on glucoside contact allergy in paediatric populations is limited. To determine the prevalence, relevance and clinical characteristics of contact allergy to glucosides in children. A retrospective review of the files of paediatric patients (≤ 16 years) who underwent patch testing for decyl glucoside (DG) and/or lauryl glucoside (LG) at the Antwerp University Hospital (UZA) in the period between January 2018 and December 2024. Among 241 children tested for DG, 148 (61.4%) were also tested for LG. DG reactions were observed in 47 patients (19.5%), with 27 (11.2%) considered positive. LG reactions occurred in 17/148 (13%), but only 4 (2.7%) were positive, all with concomitant DG reactions. Most positive DG reactions were weak (+) (25/27), whereas only 2 were strong (++). The median age was 7 years (range: 2-15), with 51.9% female. Culprit sources mostly included cosmetics. Patch test reactions to glucosides readily occur in children, and the positivity rate is surprisingly high. Besides many irritant and doubtful reactions, false-positive (+) reactions likely occur, particularly in young atopic children. Careful interpretation of positive results and complementary work-up may thus be necessary.

Substantial efforts have been progressively devoted to developing innovative, safe, and effective topical anti-aging products that not only improve the appearance of aged skin but also prioritize environmental sustainability and the responsible use of natural resources. Thus, the current study targeted to evaluate novel, natural emulsion/serum comprising new glycolipid emulsifier (lauryl glucoside/myristyl glucoside/polyglyceryl-6 laurate) and Acmella oleracea plant extract as a model active. The developed serum was assessed concerning its stability (freeze-thaw test, accelerated study), safety (in vitro screening of eye irritation potential, dermal absorption study) and efficacy (randomized, active/reference-controlled, half-face, in vivo study). Changes in skin biophysical properties, microrelief, roughness, texture, surface, and volume parameters were assessed in the periocular and perioral areas of human volunteers after 2 weeks of product application, utilizing several bioengineering and topography techniques. The stability study demonstrated favourable stability profile of the developed serum, with practically unaffected stability-indicating parameters (apparent viscosity, yield, flow point, storage and loss moduli, loss factor, pH, electrical conductivity) during freeze-thaw cycling and after 3 months of storage at 45°C. The hen's egg test on the chorioallantoic membrane of fertilized chicken eggs confirmed the absence of ocular irritation potential of investigated serum; no effects of haemorrhage, lysis or coagulation were occurred. Skin permeation study using diffusion cells revealed no permeation of spilanthol from the tested A. oleracea extract-loaded serum through the pig ear skin into the receptor medium, thus suggesting no absorption into systemic circulation. In vivo efficacy study corroborated beneficial effects of evaluated serum on the condition/appearance of facial skin, at both periocular and perioral areas-significant (p < 0.05) increase in skin hydration (10%-40%) and smoothness (~15%); significant (p < 0.05) decrease in roughness (20%-30%), scaliness (~30%), and wrinkles (~15%)-implying more hydrated, smoother, visibly milder skin. The present findings confirmed the stability, preliminary safety (no ocular irritation, no dermal absorption, and good skin tolerability), and efficacy (improved skin hydration and microrelief) of the A. oleracea extract-loaded, glycolipid-based serum, supporting its potential as a safe and effective topical anti-aging product. Des efforts considérables ont été progressivement consacrés au développement de produits anti‐âge topiques innovants, sûrs et efficaces qui non seulement améliorent l’apparence de la peau âgée, mais donnent également la priorité à la durabilité environnementale et à l’utilisation responsable des ressources naturelles. L’étude actuelle visait donc à évaluer une nouvelle émulsion naturelle/un nouveau sérum naturel comprenant un nouvel émulsifiant glycolipidique (lauryl glucoside/myristyl glucoside/laurate de polyglycéryl‐6) et un extrait végétal d’Acmella oleracea en tant que modèle actif. MÉTHODES: Le sérum développé a été évalué en ce qui concerne sa stabilité (test de congélation‐décongélation, étude accélérée), sa sécurité d’emploi (dépistage in vitro du potentiel d’irritation oculaire, étude d’absorption cutanée) et son efficacité (étude in vivo randomisée, contrôlée par un traitement actif/de référence, sur un demi‐visage). Les changements dans les propriétés biophysiques de la peau, le microrelief, la rugosité, la texture, la

Rinse-off cosmetic products, primarily shampoos, are frequently implicated in the onset of allergic contact dermatitis (ACD) caused by alkyl glucosides (AGs). AGs are increasingly popular surfactants and known contact allergens. Glucoside-induced ACD was most frequently observed with shampoos and skin-cleansing products in both consumer and occupational settings. Thereby, studies have shown that atopic individuals are the most susceptible to ACD. Also, several investigations have indicated that individuals with sensitive skin might be more prone to skin allergies. This is why the presence of AGs was investigated in shampoos and body cleansers marketed as hypoallergenic or for sensitive skin. For this purpose, the website of Amazon.com was surveyed. Four groups of cosmetics were obtained by using the following keywords: "hypoallergenic shampoo for adults," "sensitive skin shampoo for adults," "hypoallergenic body cleanser for adults," and "sensitive skin body cleanser for adults." The first 30 best-selling cosmetics in each group were investigated for the presence of AGs, by analyzing the product information pages. The results showed that as much as 56.7% of hypoallergenic shampoos contained AGs, as ingredients, whereas the percentage was somewhat lower for other product categories. Even though decyl and lauryl glucoside were nearly ubiquitously used AGs in cosmetics over the past decade, the most commonly present AG in our analysis was coco-glucoside. The results of this study indicated a necessity to include coco-glucoside in the baseline series of patch testing allergens. Industry , regulators, and healthcare providers should be made aware of the frequent presence of AGs in rinse-off cosmetic products marketed as hypoallergenic or for sensitive skin to ensure the safety and well-being of consumers and patients.

Since natural-origin, sustainable ingredients are preferred by modern consumers, novel emulsifiers and emollients keep entering the market. This study hypothesizes that a combination of in silico, instrumental tools and simplified sensory studies could be used to efficiently characterize emulsions in a shorter timeframe. A total of 22 rather simple o/w emulsions were prepared by a time/energy-saving emulsification process. A natural mixed emulsifier (Lauryl Glucoside/Myristyl Glucoside/Polyglyceryl-6 Laurate) and two emollients (both with INCI name C15-19 Alkane) were used. The performed D-optimal experimental design within the response surface method (RSM) significantly narrowed down the number of samples about to enter the stage of texture, friction and sensory studies to the samples comprising 30% of a respective Emogreen emollient and 2% or 3% of the emulsifier. The sample comprising 2% emulsifier/30% Emogreen ® L15 showed significantly higher firmness (42.12 mN) when compared to the one with 2% emulsifier/30% Emogreen ® L19 (33.62 mN), which was somewhat unexpected considering the emollients' inherent viscosity values (4.5 mPa·s for L15 and 9 mPa·s for L19). The sample with 2% emulsifier/30% Emogreen ® L19 managed to maintain the lowest friction, while the one with 3% emulsifier/30% Emogreen ® L19 released its full lubricating potential in the second part of the measurement (30-60 s). The obtained results revealed the strengths and weaknesses of each formulation, narrowing down their possible applications in the early development stage.

Alkyl glucosides are nonionic surfactants that are increasingly used in personal care products. To characterize positive patch test reactions to decyl glucoside (5% petrolatum, tested 2009-2018) and lauryl glucoside (3% petrolatum, tested 2017-2018). Retrospective analysis of patients tested by the North American Contact Dermatitis Group. Of 24,097 patients patch tested to decyl and/or lauryl glucoside, 470 (2.0%) had positive reactions. Compared with glucoside-negative patients, glucoside-positive patients had higher odds of occupational skin disease (13.4% vs 10.1%; P = .0207), history of hay fever (38.5% vs 31.6%; P = .0014), atopic dermatitis (39.0% vs 28.6%; P < .0001), and/or asthma (21.8% vs 16.5%; P = .0023). Most glucoside reactions (83.9%) were currently relevant. The most common source was personal care products (63.0%), especially hair products (16.5%) and skin cleansers (15.2%). Of 4933 patients tested to decyl and lauryl glucoside, 134 (2.7%) were positive to 1 or both; 43.4% (43 of 99) of decyl-positive patients were also positive to lauryl glucoside and 55.1% (43/78) of lauryl glucoside patients were also positive to decyl glucoside. The cohort predominantly reflects a referral population, and follow-up after testing was not captured. Glucoside positivity occurred in 2.0% of the tested patients. Reactions were often clinically relevant and linked to personal care products. Cross-reactivity was >40%.

In 2019, a number of allergens (haptens), henceforth, "the audit allergens," were considered as potential additions to the European Baseline Series (EBS), namely, sodium metabisulfite, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5% or 5% pet), linalool hydroperoxides (lin-OOH), limonene hydroperoxides (lim-OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, and lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments as well. To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe. Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the European Surveillance System on Contact Allergies testing these, as well as further collaborators from the EBS working group of the European Society of Contact Dermatitis (ESCD), and the Spanish Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea. As patch test outcome, reactions between day (D) 3 and D5 were considered. Altogether n = 12 403 patients were tested with any of the audit allergen. Positive reactions were most common to lin-OOH 1% pet. (8.74% [95%CI: 8.14-9.37%]), followed by lin-OOH 0.5% pet., and lim-OOH 0.3% pet (5.41% [95% CI: 4.95-5.89%]). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72% (95% CI: 4.2-5.28%), followed by sodium metabisulfite 1% pet. (3.75% [95%CI: 3.32-4.23%]) and Compositae mix 5% pet. (2.31% [95% CI: 1.84-2.87%]). For some allergens, clinical relevance was frequently difficult to ascertain. Despite many positive patch test reactions, it remains controversial whether lin- and lim-OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion and ultimately decision on their implementation into routine testing among the ESCD members.

The growing consumers' preferences and concerns regarding healthy ageing, youthful skin appearance, environmental protection and sustainability have triggered an ever-increasing trend towards natural, eco-friendly and ethically sourced anti-ageing products. Accordingly, this paper describes design and evaluation of novel, safe, effective and high-quality emulsion serums, completely based on ingredients of natural origin, intended for improving facial fine lines and wrinkles. Model formulations, stabilized by an innovative glycolipid mixed emulsifier (lauryl glucoside/myristyl glucoside/polyglyceryl-6 laurate) and containing Acmella oleracea extract as a model anti-ageing active, were prepared by cold process and fully assessed regarding their rheological behaviour (continuous rotational and oscillatory tests) and physical stability (dynamic-mechanical thermoanalysis - DMTA test). To study and optimize the simultaneous influence of varied formulation factors (emollients and emulsifier concentrations) on critical rheological attributes of the developed serums, a central composite design within 'design of experiments' approach was employed. The general skin performance - preliminary safety and anti-wrinkle efficacy of selected model serum, was evaluated in human volunteers, by employing several objective, non-invasive bioengineering techniques. Rheological characterization revealed favourable shear-thinning flow behaviour with yield point, and dominating elastic character (storage modulus G' > loss modulus G") in both amplitude and frequency sweeps, which together with relatively small structural change obtained in DMTA test indicated overall satisfying rheological and stability properties of formulated serums. From the established design space, and taking into account formulation cost and carbon footprint, promising model serum (desired/optimal apparent viscosity, yield point and loss factor, rather small and constant structural change), containing 15% of emollients and 1% of emulsifier, was chosen for in vivo evaluations. Screening of skin irritation effects revealed the absence of potential irritancy of investigated serum, suggesting overall satisfying skin tolerability/preliminary safety. Silicone skin replica image analysis demonstrated noticeable reduction/improvement in all measured skin wrinkle parameters after only 2 weeks of test serum application in periorbital and perioral areas, indicating its rapid and beneficial effects on the facial expression lines and wrinkles. Altogether, the results corroborate the promising potential of the developed Acmella oleracea extract-loaded emulsion serum as safe, effective and non-invasive natural anti-wrinkle product. Les préférences et les préoccupations croissantes des consommateurs concernant le vieillissement sain, l’apparence jeune de la peau, la protection de l’environnement et la durabilité ont déclenché une tendance toujours croissante vers des produits anti-âge naturels, respectueux de l’environnement et éthiques. En conséquence, ce document décrit le plan et l’évaluation de nouveaux sérums d’émulsion sûrs, efficaces et de haute qualité, entièrement basés sur des ingrédients d’origine naturelle, destinés à améliorer les ridules et rides du visage. MÉTHODES: Des formulations modèles stabilisées par un émulsifiant mixte glycolipide innovant (lauryl glucoside/myristyl glucoside/polyglycéryl-6 laurate) et contenant de l’extrait d’Acmella oleracea comme anti-vieillissement actif de modèle, ont été préparées par un procédé à froid et ont été pleinement évaluées en ce qui concerne leur comportement rhéologique (tests de rotation continue et examens oscillatoires) et stabilité physique (analyse thermomécanique dynamiq

Lauryl glucoside, a non-ionic surfactant used in various cosmetic products, is valued for its biodegradability and gentleness on the skin. However, its current production through chemical synthesis is considered unsustainable, necessitating the search for alternative methods. In this work, we engineered Escherichia coli BL21(DE3) with a novel lauryl glucoside biosynthetic pathway. Optimisation of 1-dodecanol, a lauryl glucoside precursor, was first implemented. Under optimised conditions, the strain produced 1-dodecanol at a titre of 185.39 ​± ​3.62 ​mg/L and a yield of 11.60 ​± ​0.29 ​mg/g glucose. These conditions were subsequently used to identify UDP-glycosyltransferases capable of converting 1-dodecanol to lauryl glucoside. Among six UDP-glycosyltransferases, MtH2 from Medicago truncatula showed the highest activity, with a titre and a yield of 0.72 ​± ​0.07 ​mg/L and 0.06 ​± ​0.004 ​mg/g glucose, respectively. The lauryl glucoside biosynthesis by MtH2 was confirmed using HPLC and targeted LC-MS. Moreover, the limited availability of 1-dodecanol was primarily identified as the bottleneck in this pathway. Supplementing the cells with twice the amount of 1-dodecanol led to an increase in lauryl glucoside production, achieving a titre of 13.44 ​± ​0.21 ​mg/L and a yield of 1.35 ​± ​0.04 ​mg/g glucose. Fermentation products of all strains were also monitored and suggested the redirection of carbon flux from acetate to the desired products. These findings demonstrate the successful characterisation of a newly designed lauryl glucoside biosynthetic pathway in engineered E. coli and highlight substrate limitation as a bottleneck in the pathway offering a sustainable alternative to traditional production methods.

Natural biopolymers become increasingly attractive as bio-based alternatives to petrol-based rheological modifiers, especially in personal care applications. However, many polysaccharides exhibit undesired properties in cosmetic applications such as limited viscosifying characteristics, unpleasant sensory properties, or incompatibility with certain formulation compounds. Here, a comprehensive rheological analysis of non-decorated acetan-like heteroexopolysaccharides derived from two Kozakia baliensis strains was performed in selected surfactant formulations. The results were compared to native xanthan gum and a genetically engineered xanthan variant, Xan∆gumFGL, which lacks any acetyl- and pyruvyl moieties and whose rheological properties are unaffected by saline environments. All four polysaccharides displayed a highly similar rheological performance in the non-ionic surfactant lauryl glucoside, while the rheological properties differed in amphoteric and anionic surfactants cocamidopropyl betaine and sodium laureth sulfate due to minor changes in side chain composition. Polysaccharide precipitation was observed in the presence of the cationic surfactant. Nevertheless, the native heteroexopolysaccharide derived from K. baliensis LMG 27018 shows significant potential as a salt-independent rheological modifier compared to the genetically engineered Xan∆gumFGL variant. In addition, blends of heteroexopolysaccharides from K. baliensis and several galactomannans displayed synergistic effects which were comparable to native xanthan gum-galactomannan blends. This study shows that heteroexopolysaccharides of K. baliensis are capable of further extending the portfolio of bio-based rheological modifiers.