Occurrence of alkyl glucosides in rinse-off cosmetics marketed as hypoallergenic or for sensitive skin.

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.

Physicochemical properties and stability of oil-in-water emulsions stabilized by soy protein isolate and xanthan gum.

The aim of this work was to determine rheological and disperse characteristics and stability of oil-in-water emulsions stabilized by soy protein isolate (SPI) and xanthan gum (XG), as natural components. The effects of their combination on emulsion stabilization have not been investigated yet. The existence of interactions between the two macromolecules were indicated by the influence of XG on SPI surface hydrophobicity and surface tension values. Increase in SPI concentration from 1 to 3 % shift of distribution curves towards smaller particle size, while the opposite effects of further increase of SPI was obtained. The emulsions stabilized by SPI showed shear-thinning flow behavior, which changed to thixotropic at 5 % of SPI concentration. The presence of XG in emulsions at low concentrations did not affect the size distribution of the droplets, while at 0.1 % of XG Sauter mean diameter value raised and distribution curves were shifted towards a higher particle size. The presence of XG at higher concentration resulted in thixotropic flow behavior of emulsions. Also, increase in XG concentration led to the increase in consistency index and extent of non-Newtonian behavior of emulsions and enhanced the influence of the elastic modulus and creaming stability of the systems.

Assessment of Soy Protein Acid Hydrolysate-Xanthan Gum Mixtures on the Stability, Disperse and Rheological Properties of Oil-in-Water Emulsions.

There is a growing need for natural ingredients that could be utilized for the production of food, pharmaceutical, and cosmetic emulsions. Soy protein acid hydrolysate (SPAH) is a plant-based additive used in the food industry mainly as a flavor enhancer. For the purpose of this work, however, it was mixed with a well-known natural polysaccharide, xanthan gum (XG), to produce stable 30% (w/w) sunflower oil-in-water emulsions using a rotor-stator homogenizer. In order to assess the emulsifying properties of the SPAH and its mixtures with XG, the surface tension properties of their water solutions, particle size, creaming stability, and rheological properties of the emulsions were investigated. Since the emulsions prepared using only SPAH, in various concentrations, were not stable, systems containing 5% of SPAH and 0.1, 0.2, 0.3, 0.4, or 0.5% of XG were then studied. The increase in concentration of the macromolecule led to an increase in creaming stability. The emulsions with 5% SPAH and 0.5% XG were stable for at least 14 days. The increase in XG concentration led to a decrease in d4,3, while consistency index and non-Newtonian behavior increased. The systems containing SPAH, in the absence of XG, showed shear-thinning flow behavior, which was changed to thixotropic with the addition of XG. Viscoelastic properties of emulsions containing over 0.2% of XG were confirmed by oscillatory rheological tests, demonstrating the dominance of elastic (G') over viscous (G") modulus.

Emulgels: Promising Carrier Systems for Food Ingredients and Drugs.

Novel delivery systems for cosmetics, drugs, and food ingredients are of great scientific and industrial interest due to their ability to incorporate and protect active substances, thus improving their selectivity, bioavailability, and efficacy. Emulgels are emerging carrier systems that represent a mixture of emulsion and gel, which are particularly significant for the delivery of hydrophobic substances. However, the proper selection of main constituents determines the stability and efficacy of emulgels. Emulgels are dual-controlled release systems, where the oil phase is utilized as a carrier for hydrophobic substances and it determines the occlusive and sensory properties of the product. The emulsifiers are used to promote emulsification during production and to ensure emulsion stability. The choice of emulsifying agents is based on their capacity to emulsify, their toxicity, and their route of administration. Generally, gelling agents are used to increase the consistency of formulation and improve sensory properties by making these systems thixotropic. The gelling agents also impact the release of active substances from the formulation and stability of the system. Therefore, the aim of this review is to gain new insights into emulgel formulations, including the components selection, methods of preparation, and characterization, which are based on recent advances in research studies.

Are cosmetics based on alpha hydroxy acids safe to use when purchased over the internet?

Alpha hydroxy acids (AHAs) are used in dermatology for topical treatment of skin disorders. Some regulatory bodies, including Food and Drug Administration (FDA), recommended labeling cosmetic products with sunburn alerts and proposed limitations regarding concentrations of AHAs in cosmetic products. In addition, The Cosmetic Ingredient Review (CIR) Expert Panel recommended 10% of AHAs in products as the maximal safe concentration. With a rapidly increasing trend of online purchasing of cosmetic products, it is important that their labels convey the necessary warnings and that they be harmonized with regulatory bodies regarding the recommended concentrations of AHAs. The aim of this report was to investigate whether or not the sunburn alert, as well as AHA recommendations mostly used for exfoliating cosmetic products, was visible to consumers during the online purchasing. The compliance with FDA and CIR Expert Panel standards was analyzed in the first 50 cosmetic products obtained after the conducted investigation on the Amazon.com e-commerce company website using the search term "AHA anti-aging." It was found that exfoliating cosmetic products contained AHAs in a broad range of concentrations, from 2.5 up to 70%. Nineteen out of 50 products contained a concentration of AHAs greater than recommended. Twelve products did not contain any data at all regarding the concentration of AHAs. Sunburn alerts were present in 16 out of 50 analyzed product pages. In conclusion, more efforts should be made in providing users with information and the necessity of protection from potential complications after topical AHAs product treatments.

Interactions between selected bile salts and Triton X-100 or sodium lauryl ether sulfate.

BACKGROUND: In order to develop colloidal drug carriers with desired properties, it is important to determine physico-chemical characteristics of these systems. Bile salt mixed micelles are extensively studied as novel drug delivery systems. The objective of the present investigation is to develop and characterize mixed micelles of nonionic (Triton X-100) or anionic (sodium lauryl ether sulfate) surfactant having oxyethylene groups in the polar head and following bile salts: cholate, deoxycholate and 7-oxodeoxycholate. RESULTS: The micellization behaviour of binary anionic-nonionic and anionic-anionic surfactant mixtures was investigated by conductivity and surface tension measurements. The results of the study have been analyzed using Clint's, Rubingh's, and Motomura's theories for mixed binary systems. The negative values of the interaction parameter indicate synergism between micelle building units. It was noticed that Triton X-100 and sodium lauryl ether sulfate generate the weakest synergistic interactions with sodium deoxycholate, while 7-oxodeoxycholate creates the strongest attractive interaction with investigated co-surfactants. CONCLUSION: It was concluded that increased synergistic interactions can be attributed to the larger number of hydrophilic groups at α side of the bile salts. Additionally, 7-oxo group of 7-oxodeoxycholate enhance attractive interactions with selected co-surfactants more than 7-hydroxyl group of sodium cholate.