Effects of Liquid and Bar Soaps on the Skin of Brazilian Newborns: A Randomized Controlled Trial.

INTRODUCTION: Compared to adults, newborns' skin has a thinner epidermis and stratum corneum with decreased hydration levels, higher transepidermal water loss, and a pH variation between 5.5 and 7.5. These characteristics can predispose to the occurrence of dryness, infections, and dermatological conditions. Water and liquid soap with adequate formulation have shown to be beneficial and safe for newborns' skin. However, studies evaluating the effect of bar soap, products widely used in Brazil and Latin America, are unknown. Therefore, the objective of this study was to compare the effects of liquid and bar soaps on the term newborns' skin. METHODS: This randomized controlled, parallel, single-blind clinical trial was conducted at a public university hospital in São Paulo, Brazil. 100 healthy term newborns with no congenital anomalies, acute diseases, or dermatological conditions were randomized to use liquid soap (experimental group) or bar soap (control group). Skin pH, transepidermal water loss, stratum corneum hydration, sebum content, and skin condition were assessed before and after the first bath, at 48 h, 14 days, and 28 days after birth. These evaluations were performed on the forearm, abdomen, buttocks, and thigh. In addition, the mother's perception of soap use was also evaluated. RESULTS: Data of 100 newborns were analyzed by intention to treat. The rate of retention was 53%. Newborns exposed to the liquid soap presented significantly better skin acidification (p < 0.001) and significantly better stratum corneum hydration (p < 0.001) than the skin of newborns exposed to the bar soap, regardless of the area evaluated. There were no significant differences in transepidermal water loss, sebum content, dryness, erythema, or skin breakdown and the mother's perceptions of the use of the soaps. CONCLUSION: Newborns in the experimental group presented better skin acidification and stratum corneum hydration when compared to newborns in the control group.

HPLC-TBARS-EVSC (high-performance liquid chromatography-thiobarbituric acid reactive substances-ex vivo stratum corneum) protocol: Selection of the subjects and approach to present the results.

OBJECTIVE: Nowadays, it is recognized the need for improved safety and efficacy protocols to evaluate the human stratum corneum (SC) and its interaction with topical and cosmetic formulations by minimally or non-invasive methodologies. The aim of our research work was to streamline the HPLC-TBARS-EVSC (high-performance liquid chromatography-thiobarbituric acid reactive substances-ex vivo stratum corneum) methodology, by exploring the results of a group of 18 subjects. METHODS: The study included nine women and nine men aged between 19 and 57 years old with phototypes from II to V. Sites in the forearm of each volunteer were randomly delimited, and the SC was collected by tape stripping. HPLC was used to quantify the MDA-TBA2 (malondialdehyde-thiobarbituric acid) adduct from the tape-stripped SC, irradiated and not by an ultraviolet (UV) simulator chamber. RESULTS: Observing the findings of our present investigation, and the statistical approach applied, the use of the ratio between the treatment site and control would be an adequate strategy to better discriminate and evaluate the results. Additionally, an optimal selection of the volunteers to respond specifically to the purpose of the ex vivo assay also can be considered advantageous. CONCLUSIONS: It seemed that in future studies focusing on the impact of SC UV-induced lipid peroxidation, determined by the HPLC-TBARS-EVSC, the most suitable subjects are females aged less than 35 years old, with phototype II.

OBJECTIF: Aujourd'hui, il est nécessaire d'améliorer les protocoles de sécurité d'emploi et d'efficacité pour évaluer le stratum corneum (SC) humain et son interaction avec les formulations topiques et cosmétiques par des méthodologies peu ou pas invasives. L'objectif de notre travail de recherche était de rationaliser la méthodologie HPLC-TBARS-SCEV, à savoir chromatographie en phase liquide à haute performance (High Performance Liquid Chromatography), substances réactives à l'acide thiobarbiturique (Thiobarbituric Acid Reactive Substances), stratum corneum ex vivo (SCEV), en explorant les résultats d'un groupe de 18 sujets. MÉTHODES: L'étude incluait 9 femmes et 9 hommes âgés de 19 à 57 ans présentant des phototypes II à V. Des sites de l'avant-bras de chaque volontaire ont été délimités de manière aléatoire, et le SC a été recueilli par « tape stripping ¼. La chromatographie en phase liquide à haute performance a été utilisée pour quantifier l'adduit MDA-TBA2 (malondialdéhyde - acide thiobarbiturique) à partir du SC recueilli par « tape stripping ¼, irradié et non irradié par une chambre de simulation à ultraviolets (UV). RÉSULTATS: En observant les résultats de notre recherche actuelle et l'approche statistique appliquée, l'utilisation du rapport entre le site traité et le site contrôle serait une stratégie adéquate pour mieux discriminer et évaluer les résultats. En outre, une sélection optimale des volontaires pour répondre spécifiquement à l'objectif du test ex vivo peut également être considérée comme bénéfique. CONCLUSIONS: Il semble que dans les études futures axées sur l'impact de la peroxydation lipidique induite par UV du SC, déterminé par la méthodologie HPLC-TBARS-SCEV, les sujets les plus appropriés sont les femmes âgées de moins de 35 ans présentant un phototype II.

Analytical tools for urocanic acid determination in human samples: A review.

Urocanic acid is a chromophore found in the skin that has been identified as an important immunosuppressant and carcinogenesis mediator through its photoisomerization from trans to cis form induced by ultraviolet radiation. Research on analytical methods that explore urocanic acid isomerization is indispensable to fully understand the deleterious effects mediated by this biomarker. In this context, the current relevant analytical methods for determination of these isomers in human samples are summarized in this review. The methods presented here are applicable to human samples collected by noninvasive methods (or minimally invasive), encompassing an array of analytical techniques, including high-performance capillary electrophoresis, confocal Raman spectroscopy, gas chromatography, high-performance liquid chromatography, and mass spectrometry, among others. Developed high-performance liquid chromatography methods have proven to be advantageous, allowing noninvasive collections for in vivo analysis and the confocal Raman, specially, for real-time analysis. Among all these methods, high-performance liquid chromatography is the most investigated one with mass spectrometry or ultraviolet detector, and the mass spectrometry detector being the most studied in the last years, demonstrating high sensitivity, very low detection limits, and accurate identification, especially for clinical investigations.

Skin impacts from exposure to ultraviolet, visible, infrared, and artificial lights - a review.

Social distancing is conducive to grow the impact of artificial light in the daily life of the worldwide population with reported consequences to the skin. Sunlight is also essential for human development, indeed, solar radiation is composed of different types of wavelengths, which generate different skin effects. It can be divided into ultraviolet (UV), infrared (IR), and visible. UV radiation (UVA and UVB) has cutaneous biological effects ranging from photoaging, immunosuppression to melanoma formation, through the production of reactive oxygen species (ROS), inflammation and elevation of the energy state of organic molecules, changing the DNA structure. IR radiation reaches deeper layers of the skin and is also related to the generation of ROS, photoaging and erythema while visible light is responsible for generating ROS, pigmentation, cytokine formation, and matrix metallopeptidases (MMPs). Furthermore, artificial light could be harmful to the skin, as it can generate ROS, hyperpigmentation, and stimulate photoaging. Currently, we briefly summarized the cutaneous biological effects of sunlight, as well as artificial light on skin and remarked the opportunity of the evolution of current photoprotective formulas through new strategies with broad spectrum protection.

(Bio)Technological aspects of microalgae pigments for cosmetics.

Photosynthetic microorganisms convert carbon dioxide and solar radiation into interesting bioactive compounds not yet entirely explored. Several species of microalgae are known to be rich in colored high-valuable components that, although remarkable, are poorly explored as natural sources of pigments for cosmetics. Pigments associated to photosynthetic activity include chlorophyll, ß-carotene, astaxanthin, xanthophylls, and phycobiliproteins, many of which have shown high potential as cosmetic actives due to their antioxidant, immune-enhancing, and anti-inflammatory properties. In the last decade, concern with a young and beautiful appearance has emerged, encouraging many consumers to use anti-aging cosmetics daily. As a result, the cosmetic market has been growing and evolving rapidly to meet consumer expectations. However, due to regular use and the sensitive nature of facial skin, local adverse reactions may often occur, such as irritation, sensitization, or photoreactions, and safety evaluation is mandatory prior to marketing. It is, therefore, understandable that new actives from natural sources, such as microalgae, are perceived as attractive alternatives for consumers who seek ingredients without allergenic potential. Thus, the cosmetic industry has recently started to explore the inclusion of compounds extracted from microalgae and cyanobacteria in innovative formulations. Herein, we revised nontraditional microalgae species for pigment production with cosmetic applications, indicating those that could also be considered potential ingredients for innovative cosmetics. KEY POINTS: • Extraction methods for pigments from photosynthetic microorganisms were compiled. • Innovative cosmeceuticals could be developed with natural pigments. • Safety features of such natural pigments were also described.

Safety and Antioxidant Efficacy Profiles of Rutin-Loaded Ethosomes for Topical Application.

Topical application of dermocosmetics containing antioxidant and/or the intake of antioxidants through diet or supplementation are remarkable tools in an attempt to slow down some of the harmful effects of free radicals. Rutin is a strong antioxidant compound used in food and pharmaceutical industries. It was established that rutin presents a low skin permeation rate, a property that could be considered an inconvenience to the satisfactory action for a dermocosmetic formulation to perform its antioxidant activity onto the skin. Therefore, it is indispensable to improve its delivery, aiming at increasing its antioxidant capacity in deeper layers of the epidermis, being a possibility to associate the rutin to liposomal vesicles, such as ethosomes. Thus, in this work, the pre-clinical safety of rutin-loaded ethosomes was investigated employing an in vitro method, and the clinical safety and efficacy were also assessed. Rutin-loaded ethosomes were efficaciously obtained in a nanoscale dimension with a relevant bioactive compound loading (80.2%) and provided antioxidant in vitro activity in comparison with the blank sample. Pre-clinical and clinical safety assays assured the innocuous profile of the rutin-loaded ethosomes. The ethosomes containing the bioactive compound accomplished a more functional delivery system profile, since in the tape stripping assay, the deeper layers presented higher rutin amounts than the active delivered in its free state. However, the ex vivo antioxidant efficacy test detected no positive antioxidant activity from the rutin-loaded ethosomes, even though the in vitro assay demonstrated an affirmative antioxidant action.

Quality by design (QbD), Process Analytical Technology (PAT), and design of experiment applied to the development of multifunctional sunscreens.

Multifunctional formulations are of great importance to ensure better skin protection from harm caused by ultraviolet radiation (UV). Despite the advantages of Quality by Design and Process Analytical Technology approaches to the development and optimization of new products, we found in the literature only a few studies concerning their applications in cosmetic product industry. Thus, in this research work, we applied the QbD and PAT approaches to the development of multifunctional sunscreens containing bemotrizinol, ethylhexyl triazone, and ferulic acid. In addition, UV transmittance method was applied to assess qualitative and quantitative critical quality attributes of sunscreens using chemometrics analyses. Linear discriminant analysis allowed classifying unknown formulations, which is useful for investigation of counterfeit and adulteration. Simultaneous quantification of ethylhexyl triazone, bemotrizinol, and ferulic acid presented at the formulations was performed using PLS regression. This design allowed us to verify the compounds in isolation and in combination and to prove that the antioxidant action of ferulic acid as well as the sunscreen actions, since the presence of this component increased 90% of antioxidant activity in vitro.

Optical coherence tomography to evaluate the effects of oxidative hair dye on the fiber.

BACKGROUND/PURPOSE: Oxidative hair dyes can damage the hair, since these chemical procedures are involved to change the fiber structure and therefore changes in their mechanical and surface properties. Evaluate and compare the effect of the two colors of oxidative hair dye emulsions on Caucasian hair. This research analyzed the Dark brown hair untreated (I); Dark brown hair treated with light brown dye (II); Dark brown hair treated with light blond dye (III); Light blond hair untreated (IV); Light blond hair treated with light brown dye (V); Light blond hair treated with light blond dye (VI) on Caucasian hair. METHODS: The hair samples were submitted to breaking strength, color, and optical coherence tomography (OCT) analysis. RESULTS: For the breaking strength assay no presented statistically significant differences between treatments. The parameters of color and brightness can differ in some hair dye formulations, but also the hair type can respond differently. The OCT images of the sample I and IV was possible observed, clearly Medulla and Cortex, which was not observed clearly after treatment with both oxidative hair dye colors. CONCLUSION: Based on the results, the oxidative hair dyes increased alteration in color and ultrastructure of hair.

Development of ciclopirox olamine topical formulations: evaluation of drug release, penetration and cutaneous retention.

With the aim of reducing system absorption and consequently, the side effects, and simultaneously select a penetration enhancing, three topical formulations with 0.5% ciclopirox olamine (CO) and 15% of propylene glycol (PG), ethoxydiglycol or oleic acid were developed and evaluated regarding the skin penetration and cutaneous retention of the drug using Franz diffusion cells. Release experiments were performed through synthetic membrane while dermatomed pig ear skin was used to evaluate CO skin penetration and skin retention. Retention studies were carried out applying tape stripping method and dosing CO in stratum corneum and in epidermis and dermis. A HPLC method was validated for quantifying CO. All formulations tested with synthetic membrane presented no retention of the drug. Permeation data suggested that there was no systemic absorption of ciclopirox olamine from the studied formulations, even when the skin penetration enhancers were applied. Higher concentrations of the drug were found in the stratum corneum (SC) and also in epidermis and dermis, for all of the developed formulations. The addition of enhancers improved the penetration and cutaneous retention of CO, and propylene glycol promoted higher concentrations in epidermis and dermis, probably because its cumulative effect on the skin and by an efficient solvent power.

Optimization of primaquine diphosphate tablet formulation for controlled drug release using the mixture experimental design.

A tablet formulation based on hydrophilic matrix with a controlled drug release was developed, and the effect of polymer concentrations on the release of primaquine diphosphate was evaluated. To achieve this purpose, a 20-run, four-factor with multiple constraints on the proportions of the components was employed to obtain tablet compositions. Drug release was determined by an in vitro dissolution study in phosphate buffer solution at pH 6.8. The polynomial fitted functions described the behavior of the mixture on simplex coordinate systems to study the effects of each factor (polymer) on tablet characteristics. Based on the response surface methodology, a tablet composition was optimized with the purpose of obtaining a primaquine diphosphate release closer to a zero order kinetic. This formulation released 85.22% of the drug for 8 h and its kinetic was studied regarding to Korsmeyer-Peppas model, (Adj-R(2) = 0.99295) which has confirmed that both diffusion and erosion were related to the mechanism of the drug release. The data from the optimized formulation were very close to the predictions from statistical analysis, demonstrating that mixture experimental design could be used to optimize primaquine diphosphate dissolution from hidroxypropylmethyl cellulose and polyethylene glycol matrix tablets.

Influence of the Mixtures of Vegetable Oil and Vitamin E over the Microstructure and Rheology of Organogels.

Candelilla wax (CW) and 12-hydroxystearic acid (12HSA) are classic solid-fiber-matrix organogelators. Despite the high number of studies using those ingredients in oily systems, there is scarce literature using a mixture of oil and antioxidants. Vitamin E (VE) is an important candidate for its lipophilicity and several applications on pharmaceutical, cosmetics, and food industries. In this work, we investigated the influences of mixtures between vegetable oil (VO) and VE on the microstructures and rheological properties of CW and 12HSA organogels. A weak gel (G''/G' > 0.1) with a shear-thinning behavior was observed for all samples. The presence of VE impacted the gel strength and the phase transition temperatures in a dose-dependent pattern. Larger and denser packed crystals were seen for 12HSA samples, while smaller and more dispersed structures were obtained for CW organogels. The results obtained in this work allowed the correlation of the structural and mechanical properties of the organogels, which plays an important role in the physical-chemical characteristics of these materials.

Vaccinium myrtillus L. extract associated with octocrylene, bisoctrizole, and titanium dioxide: in vitro and in vivo tests to evaluate safety and efficacy.

OBJECTIVE: The harmful effects induced by ultraviolet exposition and the significant increment in skin cancer diagnosis confirm the necessity to develop effective and safe sunscreens. Limited efficacy and cutaneous adverse reactions of traditional formulations drove the incorporation of natural extracts into multifunctional sunscreens. Vaccinium myrtillus L. extract (VME), that contains anthocyanins and flavonoids, is a potential candidate for such systems. METHODS: Considering that, we performed in vitro and in vivo tests to evaluate the sun protection factor (SPF), photostability, and safety of sunscreen samples containing VME. RESULTS: As main results, the SPF was reduced in both in vitro and in vivo evaluation in the presence of VME; nonetheless, the samples were photostable and safe. CONCLUSION: Further investigation is required to better understand the unexpected effects of VME over photoprotection, decreasing the SPF value. As a conclusion, even with interesting findings, we highlight the importance of case-by-case investigations to develop multifunctional bioactive sunscreens.

Impact of Acid ("Progressive Brush") and Alkaline Straightening on the Hair Fiber: Differential Effects on the Cuticle and Cortex Properties.

Background: Glyoxylic acid has emerged as a safe alternative to formol (formaldehyde) use as a hair straightener/relaxer. However, the possible damage to the hair fiber after its application is low known and/or published in the literature. Aims: This work aims to characterize hair locks treated with glyoxylic acid compared to traditional alkaline straighteners such as sodium and guanidine hydroxide and ammonium thioglycolate. Materials and Methods: The morphology of the hair cuticles was observed by scanning electron microscopy. Protein loss was assessed by the Lowry method modified by Peterson and as mechanical properties that were expressed in terms of tensile strength. Results: All products (sodium and guanidine hydroxides and ammonium thioglycolate) caused protein loss of about 2.5 µg/g, except glyoxylic acid that caused the worst damage (3.5 µg/g), in relation to the untreated (virgin) hair (1.12 µg/g), indicating that the chemical treatments can cause hair damage in both cuticles and cortex. The force to break the fibers treated with traditional straighteners based on sodium hydroxide, guanidine hydroxide, and ammonium thioglycolate was statistically the same. Conclusion: The treatment with glyoxylic acid showed rupture tensile statistically equivalent to the alkaline straighteners. The mechanism of action of glyoxylic acid does not appear to be based on breaking and rearrangement of disulfide bridges, but altered them, that influenced the hair strength. However, it is also essential to consider other factors relevant: technical application technique, reaction time, and interval of reapplication of the product, as this can change the pattern of the results obtained.

Potential use of essential oils in cosmetic and dermatological hair products: A review.

BACKGROUND: Essential oils have great interest among the increasing demand for herbal cosmetics in the market. They are natural sources of biologically active ingredients due to the wide application of such compounds as well as their particular chemical composition. Several researches have evaluated the effectiveness of these bioactive ingredients for use in cosmeceuticals, mainly in both hair scalp and shaft hair damage repair. Thus, the amounts and their associations define the properties of these compositions with interest for hair cosmetic use, such as antioxidant, inflammatory, and antimicrobial activities. Because they are complex compounds, their actions on the skin, hair scalp, and shaft are not yet fully understood. AIMS: The purpose of this review is to highlight the relevant researches and findings on essential oils in hair care. METHODS: In order to achieve this objective, the present work comprises an updated bibliographic review related to essential oils used in hair care. RESULTS: It was possible to observe that cosmeceuticals containing essential oils applied to the scalp are preferable for topical activity. Also, it was noticed that there are few reports regarding their use in hair shaft. However, it was found that some oils are used to intensify the brightness and fix the hair color. CONCLUSIONS: This work demonstrated that the use of essential oils in both cosmetic products (industrial application) and those associated with oils carriers (as individual protocols) may lead to satisfactory results in the treatment of some scalp dysfunctions.

Rubus rosaefolius extract as a natural preservative candidate in topical formulations.

Even though the synthetic preservatives may offer a high antimicrobial efficacy, they are commonly related to adverse reactions and regarded as having potentially harmful effects caused by chronic consumption. The development of natural preservatives provides a way of reducing the amount of synthetic preservatives normally used in pharmaceutical and cosmetic preparations. In addition, these agents have less toxic effects and represent a possible natural and safer alternative of the preservatives. The purpose of this research was to evaluate the Rubus rosaefolius Smith extract efficiency as a natural preservative in base formulations. Of the extract, 0.2% (w/w) was assayed for its effectiveness of antimicrobial protection in two different base formulations (emulsion and gel). The microbial challenge test was performed following the standard procedures proposed by The United States Pharmacopoeia 33nd, European Pharmacopoeia 6th, Japanese Pharmacopoeia 15th, and the Cosmetics, Toiletries, and Fragrance Association using standardized microorganisms. The results demonstrated that R. rosaefolius extract at the studied concentration reduced the bacterial inocula, satisfying the criterion in all formulations, even though it was not able to present an effective preservative behavior against fungi. Thus, the investigation of new natural substances with preservative properties that could be applied in pharmaceutical and cosmetic products is relevant due to the possibility of substituting or decreasing the concentration of synthetic preservatives, providing a way for the development of safer formulas for the use of consumers.

A short review of alternative ingredients and technologies of inorganic UV filters.

BACKGROUND: The growing need to use sunscreens is a concrete reality, and it is associated with the increase in the population's awareness of the ultraviolet (UV) radiation damage. Inorganic UV filters promote the formation of particles/pigments film over the skin surface, reflecting, dispersing, and absorbing the radiation. Investigations of this class of filters demonstrate the emergence of alternative ingredients and new technologies. AIMS AND METHODS: In this review, we presented potential candidates for alternative UV inorganic filters, such as hydroxyapatite, cerium dioxide, and hydrotalcite. RESULTS: Specialized literature identified hydroxyapatite and cerium dioxide as actives with good performances, with a broad spectrum of absorption against UV radiation. Both of them were considered safe against degradation and skin erythema formation. Inorganic compounds as an alternative to circumvent degradation problems of organic UV filters containing PABA were also analyzed, with hydrotalcite having a good performance in improving the performance of classic ingredients, bypassing photoinstability, and improving safety, in addition to preventing skin irritability. CONCLUSION: Further investigations of these ingredients and interactions with sunscreen formulations are necessary to overall explore their safety and efficacy, encouraging future researches for more inorganic UV filters.

An Overview on Topical Administration of Carotenoids and Coenzyme Q10 Loaded in Lipid Nanoparticles.

Carotenoids and coenzyme Q10 are naturally occurring antioxidant compounds that are also found in human skin. These bioactive compounds have been the focus of considerable research due to their antioxidant, anti-inflammatory, and photoprotective properties. In this review, the current state of the art in the encapsulation of carotenoids and coenzyme Q10 in lipid nanoparticles to improve their bioavailability, chemical stability, and skin absorption is discussed. Additionally, the main findings are highlighted on the cytotoxic and photoprotective effects of these systems in the skin.

Preclinical and clinical studies to evaluate cutaneous biodistribution, safety and efficacy of UV filters encapsulated in mesoporous silica SBA-15.

Innovative technologies have been designed to improve efficacy and safety of chemical UV filters. Encapsulation can enhance efficacy and reduce transdermal permeation and systemic exposure. The aims of this work were (i) to determine the cutaneous biodistribution of avobenzone (AVO), oxybenzone (OXY), and octyl methoxycinnamate (OMC) incorporated in mesoporous silica SBA-15 and (ii) to perform preclinical (in vitro) and (iii) clinical safety studies to demonstrate their innocuity and to evaluate sun protection factor (SPF) in humans. Skin penetration studies showed that deposition of OXY and AVO in porcine and human skin after application of stick formulation with incorporated filters (stick incorporated filters) was significantly lower than from a marketed (non-encapsulated) stick. Cutaneous deposition and transdermal permeation of OXY in and across human skin were 3.8-and 13.4- fold lower, respectively, after application of stick entrapped filters. Biodistribution results showed that encapsulation in SBA-15 decreased AVO and OXY penetration reaching porcine and human dermis. Greater deposition (and permeation) of OXY in porcine skin than in human skin, pointed to the role of follicular transport. Stick incorporated filters had good biocompatibility in vivo and safety profiles, even under sun-exposed conditions. Entrapment of UV filters improved the SPF by 26% and produced the same SPF profile as a marketed stick. Overall, the results showed that SBA-15 enabled safety and efficacy of UV filters to be increased.

Ex vivo penetration analysis and anti-inflammatory efficacy of the association of ferulic acid and UV filters.

BACKGROUND: Unprotected chronic exposure to ultraviolet (UV) radiation generates many harmful effects to human skin and sunscreens are essential to health, however, traditional products do not provide enough protection against cutaneous oxidative stress, a process amplified by UV radiation. Therefore, the development of multifunctional photoprotective formulations seems to be a more efficacious approach, since these enable the absorption/reflection of UV radiation and maintain the cutaneous homeostasis. OBJECTIVES: In the present study, ferulic acid (FA), a well-known antioxidant, has been combined with two UV filters, bemotrizinol and ethylhexyl triazone, and the safety and efficacy of this formulation has been assessed combining ex vivo and in vivo methods. METHODS: Skin permeation assays were performed by applying the formulation in the volar forearm of participants, after which consecutive samples of the stratum corneum were collected by tape stripping, and the quantification of FA, bemotrizinol and ethylhexyl triazone was performed by high-performance liquid chromatography (HPLC). Also, the FA anti-inflammatory action in combination with the UV filters was probed through a method employing Laser Doppler flowmetry to measure the vasodilatory response to methyl nicotinate topical application. RESULTS: Skin permeation assay was able to characterize the penetration depth of each substance. It should also be noted that a specific HPLC analytical method was developed in this study to enable the rapid simultaneous quantification of the three substances. Results from Laser Doppler flowmetry showed that the FA was able to mitigate the vasodilatory response. CONCLUSIONS: FA proved to be a valuable resource in a multifunction sunscreen, not only providing an increase in the SPF of sunscreens, previously published, but also decreasing the extent of inflammation.

Vitamin E-loaded bigels and emulsions: Physicochemical characterization and potential biological application.

Bigels have been studied as topical formulations for its benefits over sensory and drug delivery parameters. However, there is still few evidences about the properties of the combination of organogelators, oily phases and bioactive molecules into rheological and stability behavior. We investigated the use of classical organogelators (candelilla wax and 12-hydroxystearic acid) and oily phases (sunflower and mineral oil) in 5/95 organogel/polymeric hydrogel ratio to compare vitamin E bigels with its corresponding emulsions. The rheological measurements, microstructure, physical and oxidative stability properties and biological behavior were evaluated. The obtained oil-in-water bigels and emulsions showed crystallization pattern at the interface with high thermal and centrifuge-stress stability. Viscoelastic weak gels were obtained with higher thixotropy and consistency of 12-hydroxystearic bigels. The diameter of the inner phase was increased by vitamin E, despite its little influence over physical and oxidative stability of bigels and emulsions. Those findings indicated that sensory attributes may be regulated by the organogel composition.