Ethylhexylglycerin Research Articles

Evaluation of the antioxidant and antityrosinase activities of Prosopis juliflora fruit extract as a novel multifunctional bioactive ingredient and its potential applicability in pro-ageing and skin colour harmonization cosmetic products.

Prosopis juliflora, commonly known as algaroba or mesquite, was introduced and has since proliferated throughout the semi-arid region of the Caatinga biome. Various studies have documented its properties, including antimicrobial, antioxidant, and antitumor activities, attributed to the presence of diverse secondary metabolites such as alkaloids, terpenoids, tannins, and flavonoids. The objective of this study was to evaluate the antioxidant and antityrosinase activities of P. juliflora fruit extract as a multifunctional active ingredient, and to develop cosmetic formulations containing this vegetal extract for potential applications in skincare products targeting pro-ageing and skin colour homogenization properties. The extraction process followed established protocols. Chemical characterization of the extract involved quantification of total flavonoids and phenolic compounds, along with Liquid Chromatography-Mass Spectrometry (LC-MS) analysis. Invitro antioxidant activity was assessed using different methods. Antityrosinase activity was determined by employing enzymatic assays. Cosmetic formulations containing Disodium EDTA, Phenoxyethanol (and) Ethylhexyl Glycerin, Distilled Water, Sodium Acrylates Copolymer Lecithin, Polyacrylamide (and) C13-14 Isoparaffin (and) Laureth-7, and 3.0% of the investigated plant extract were subjected to preliminary and accelerated stability tests. The extract demonstrated a concentration of total flavonoids (1.71 ± 0.26 μg EQ/mg) and exhibited concentrations of phenolic compounds at 0.21 ± 0.01 mg EAG/g. Metabolites such as flavonoids and saponins were annotated, as well as some of their respective glycosidic derivatives. The extract showed antioxidant potential and the ability to inhibit the oxidation cascade in both the initiation and propagation phases. Moreover, the extract exhibited noteworthy inhibition of antityrosinase activity, presenting 62.48 ± 2.09 at a concentration of 30.00 mg/mL. The formulations were stable in accelerated stability tests over a 60-day period. This research not only demonstrates scientifically by demonstrating the potential of a plant from the Caatinga biome with antioxidant and antityrosinase properties in the development of cosmetic products aimed at pro-ageing effects and skin colour harmonization, but also adds value to the P. juliflora production chain. This valorization encompasses various aspects which include environmental, social, and biodiversity responsibilities.

Patch Testing to Ethylhexylglycerin: The North American Contact Dermatitis Group Experience, 2013-2018.

Ethylhexylglycerin (EHG) is a recently recognized contact allergen. The aims of the study were to characterize individuals with positive patch test reactions to EHG and to analyze reaction strength, clinical relevance, and allergen sources. This study was a retrospective analysis of the patients patch tested to EHG (5% petrolatum) by the North American Contact Dermatitis Group (2013-2018). Of 15,560 patients tested to EHG, 39 (0.25%) had positive (final interpretation of "allergic") reactions. Most were female (71.8%) and/or older than 40 years (76.9%). There were no statistically significant differences between age, sex, or atopic history when compared with EHG-negative patients. The most common anatomic sites of dermatitis were the face (28.2%) and scattered generalized distribution (25.6%). Most EHG-positive reactions were + (35.9%) or ++ (33.3%). Current clinical relevance was high (79.5%); none, however, were related to occupation. Personal care products were the most common source of exposure to EHG (59.0%). Ethylhexylglycerin is a rare contact allergen; the positive frequency of 0.25% is similar to other low allergenic preservatives including parabens, benzyl alcohol, and phenoxyethanol. The patch test concentration of 5.0% seems to be nonirritating. Although relatively uncommon, EHG reactions were usually clinically relevant (79.5%), often because of moisturizers/lotions/creams.

Integrated approaches to testing and assessment as a tool for the hazard assessment and risk characterization of cosmetic preservatives.

The safety assessment of cosmetic products is based on the safety of the ingredients, which requires information on chemical structures, toxicological profiles, and exposure data. Approximately 6% of the population is sensitized to cosmetic ingredients, especially preservatives and fragrances. In this context, the aim of this study was to perform a hazard assessment and risk characterization of benzalkonium chloride (BAC), benzyl alcohol (BA), caprylyl glycol (CG), ethylhexylglycerin (EG), chlorphenesin (CP), dehydroacetic acid (DHA), sodium dehydroacetate (SDH), iodopropynyl butylcarbamate (IPBC), methylchloroisothiazolinone and methylisothiazolinone (MCI/MIT), methylisothiazolinone (MIT), phenoxyethanol (PE), potassium sorbate (PS), and sodium benzoate (SB). Considering the integrated approaches to testing and assessment (IATA) and weight of evidence (WoE) as a decision tree, based on published safety reports. The hazard assessment was composed of a toxicological matrix correlating the toxicity level, defined as low (L), moderate (M), or high (H) and local or systemic exposure, considering the endpoints of skin sensitization, skin irritation, eye irritation, phototoxicity, acute oral toxicity, carcinogenicity, mutagenicity/genotoxicity, and endocrine activity. In a risk assessment approach, most preservatives had a margin of safety (MoS) above 100, except for DHA, SDH, and EG, considering the worst-case scenario (100% dermal absorption). However, isolated data do not set up a safety assessment. It is necessary to carry out a rational risk characterization considering hazard and exposure assessment to estimate the level of risk of an adverse health outcome, based on the concentration in a product, frequency of use, type of product, route of exposure, body surface location, and target population.

Effect of cosmetic chemical preservatives on resident flora isolated from healthy facial skin.

Healthy skin harbors numerous microbes known to maintain its health and prevent attacks from external pathogens. The influence of chemical preservatives commonly used in cosmetic products on facial resident flora remains poorly characterized. In this study, we aimed to investigate the antibacterial activity of five such preservatives on in vitro cultivated skin-resident bacteria. Both Gram-positive and Gram-negative bacteria were isolated on blood agar, tryptic soy agar, and nutrient agar; Gram-negative bacteria were then selected on Hank's balanced salt solution containing antibiotics and Reasoner's 2A. The minimum inhibitory concentrations (MICs) of methylisothiazolinone (MTI), iodopropynyl butylcarbamate (IPBC), ethylhexylglycerin (EHG), methylparaben (MP), and phenoxyethanol (PE) were estimated for nine facial resident bacteria, Escherichia coli, and Staphylococcus aureus using serial broth dilution in vitro. The maximum test concentrations coincided with the upper limits set by the "Cosmetic Safety and Technical Specification" (2015 edition, China). Nine facial resident bacteria were isolated from 14 healthy adults: Staphylococcus epidermidis, Staphylococcus capitis, Kocuria, Micrococcus luteus, Bacillus, Acinetobacter, Pseudomonas parafulva, Pseudomonas oleovorans, and Roseomonas cervicalis. MTI and IPBC displayed the strongest effect on all tested strains (MICs ≤0.01%), followed by EHG and MP (MICs ≤0.3%), and finally PE with the weakest effect (MIC ≤1%). The five chemical preservatives assayed inhibited survival of the nine facial resident bacteria isolates, when tested at the maximum allowed limit. The corresponding MICs will provide a reference for the effective utilization of these compounds in product formulations.

Ethylhexylglycerin Impairs Membrane Integrity and Enhances the Lethal Effect of Phenoxyethanol.

Preservatives are added to cosmetics to protect the consumers from infections and prevent product spoilage. The concentration of preservatives should be kept as low as possible and this can be achieved by adding potentiating agents. The aim of the study was to investigate the mechanisms behind potentiation of the bactericidal effect of a commonly used preservative, 2-phenoxyethanol (PE), by the potentiating agent ethylhexylglycerin (EHG). Sub-lethal concentrations of EHG (0.075%) and PE (0.675%) in combination led to rapid killing of E. coli (> 5 log reduction of cfu after 30 min), leakage of cellular constituents, disruption of the energy metabolism, morphological deformities of cells and condensation of DNA. Used alone, EHG disrupted the membrane integrity even at low concentrations. In conclusion, sub-lethal concentrations of EHG potentiate the effect of PE through damage of the cell membrane integrity. Thus, adding EHG to PE in a 1:9 ratio has a similar effect on membrane damage and bacterial viability as doubling the concentration of PE. This study provides insight about the mechanism of action of a strong potentiating agent, EHG, which is commonly used in cosmetics together with PE.