Development and Efficacy Evaluation of Innovative Cosmetic Formulations with Caryocar brasiliense Fruit Pulp Oil Encapsulated in Freeze-Dried Liposomes.

Encapsulation and drying technologies allow the engineering of innovative raw materials from plant biodiversity, with potential applications in pharmaceutical and cosmetic fields. Lipid-based nanoencapsulation stands out for its efficiency, ease of production, and versatility in encapsulating substances, whether hydrophilic or lipophilic. This work aimed at encapsulating pequi oil in liposomes and freeze-dried liposomes to enhance its stability and functional benefits, such as skin hydration and anti-aging effects, for use in innovative cosmetic formulations. Pequi oil-extracted from the Caryocar brasiliense fruit pulp, a plant species from Brazilian plant biodiversity-is rich in secondary metabolites and fatty acids. Liposomes and dried liposomes offer controlled production processes and seamless integration into cosmetic formulations. The physicochemical analysis of the developed liposomes confirmed that the formulations are homogeneous and electrokinetically stable, as evidenced by consistent particle size distribution and zeta potential values, respectively. The gel-type formulations loaded with the dried liposomes exhibit enhanced skin hydration, improved barrier function, and refined microrelief, indicating improvements in skin conditions. These results highlight the potential of dried liposomes containing pequi oil for the development of innovative cosmeceutical products. This research contributes to the valorization of Brazilian biodiversity by presenting an innovative approach to leveraging the dermatological benefits of pequi oil in cosmetic applications.

Film-Forming, Moisturizing, and Sensory Properties of a Cosmetic Formulation Containing Tara Gum and Brazilian Berry Extracts.

The development of cosmetic formulations with moisturizing and film-forming properties has been very important to help keep skin physiology and protection. In this context, this study aimed to develop a cosmetic formulation containing Tara gum and Brazilian berry extract and evaluate its physical-mechanical, film-forming, and sensory properties. A gel formulation was developed based on Tara gum added to Plinia cauliflora extract and was characterized by its spreadability profile and sensory properties. A clinical study was carried out with ten participants to evaluate the skin microrelief, stratum corneum water content, transepidermal water loss (TEWL), and skin morphological characteristics by reflectance confocal microscopy (RCM) before and after 2 h of application of the formulations. The formulation with Brazilian berry significantly decreased the work of shear parameter, which can be correlated with improved spreadability in the sensory analysis. The clinical study showed that both formulations improved skin hydration and reduced the TEWL. The RCM imaging analysis showed the visible film on the skin surface, a decrease in the size of furrows, an increase in the reflectance of the interkeratinocytes, and reflectance of the stratum corneum for both formulations. These results were more pronounced for the formulation containing Brazilian berry. The Tara gum in the gel formulation promoted the formation and visualization of a polymeric net on the stratum corneum surface, demonstrated by the images obtained from RCM. However, the formulation added with the Brazilian berry extract improved the skin microrelief, honeycomb pattern of the epidermis, and skin hydration in deeper layers of the epidermis.

Evaluation of Morphological and Structural Skin Alterations on Diabetic Subjects by Biophysical and Imaging Techniques.

Diabetes causes increased production of advanced glycation end products (AGEs), which may lead to irreversible damage to collagen fibers, and early and more accentuated signs of skin aging. Thus, the objective of this study was to evaluate diabetic skin's mechanical and morphological characteristics and compare these to healthy skin. Twenty-eight female participants aged between 39 and 55 years were enrolled: half had type 2 diabetes, and the others were healthy. Wrinkles, transepidermal water loss (TEWL), stratum corneum water content, skin color, elasticity, morphological and structural characteristics of epidermis and dermis echogenicity were evaluated using biophysical and skin imaging techniques. Higher TEWL values were observed in participants with diabetes, who also showed lower skin elasticity and wrinkles with greater volume, area, and depth. In addition, the Reflectance Confocal Microscopy (RCM) imaging analysis showed that all participants with diabetes presented polycyclic papillae and deformed and amorphous collagen fibers. The obtained data showed significant differences between healthy and diabetic skin and could help develop more specific topical treatments to improve the treatment of skin conditions in people with diabetes. Finally, RCM is an advanced imaging technique that allows for a more profound analysis of diabetic skin, which could assist in the evaluation of dermocosmetic treatments to improve the skin alterations caused by this disease.

Film-Forming Properties of Topical Formulations for Skin and Hair: In Vivo and In Vitro Studies Using Biophysical and Imaging Techniques.

The film-forming effect is an important property of formulations for skin improvement and hair protection. Reflectance confocal microscopy, an advanced imaging technique, is an important tool for its evaluation. Thus, the aim of this study was to evaluate the film-forming properties of cosmetic formulations based on starches and containing a Spirulina maxima extract after their application to skin and hair, using sensorial analysis and instrumental measurements, with emphasis on reflectance confocal microscopy. Two formulations based on starches and PEG-75 lanolin containing or not (Vehicle) a Spirulina maxima dry extract were developed. The rheological behavior and sensorial properties of both formulations were evaluated. The film-forming property on the skin was evaluated in terms of skin hydration by RCM imaging analysis and transepidermal water loss (TEWL). The hair tresses were evaluated in terms of mechanical properties and RCM imaging analysis. The formulations showed pseudoplastic behavior and a low hysteresis area. In addition, the presence of Spirulina in the formulation did not interfere in the rheological parameters. Both formulations reduced TEWL and maintained the stratum corneum water content. The protective effect was also observed in the hair, since the application of the formulation with Spirulina showed a better performance in the tensile test when compared to vehicle. Thus, the proposed formulation showed film formation on the skin and hair surface that brought immediate benefits such as a reduction of TEWL. Finally, the formulations were shown to have film-forming effects and their use can be suggested for skin and hair protection against daily damage.

Impacts of sun protection and skin care habits in the biophysical and morphological properties of young men skin.

BACKGROUND: Previous studies have demonstrated that UVB radiation may cause changes in the epidermal permeability barrier and in the stratum corneum hydration. It is also well known that sun exposure causes erythema, skin cancer, and other physiologic alterations. Furthermore, because of the cultural barrier, men usually apply less sunscreen. AIMS: The objective of this study was to evaluate the cosmetic use and sun protection habits of young men, correlating their lifestyle with the biophysical and morphological skin characteristics, as well as to study how skin unprotected sun exposure can affect these features even in young people. PATIENTS/METHODS: 60 participants between 18 and 28 years old were divided into two groups: with photoprotection habits (PP habits) and without photoprotection habits (No PP habits). They were questioned about their sunscreen and cosmetic products use. The skin parameters were evaluated using biophysical and skin imaging techniques. RESULTS AND CONCLUSION: 60% of the participants did not apply sunscreen often, and 80% did not consume other skin care products. No PP habits group presented an increase in the transepidermal water loss-TEWL and sebum level, as well as a reduction in the stratum corneum water content and dermis echogenicity. The skin characteristics evaluated in this study were correlated with the sun protection habits and skin care behavior showing that men face some sociocultural barrier to start the use of cosmetic products. Thus, it is important to consider this information for the dermatological clinical and development of cosmetic products for men's skin.

Safety and efficacy of combined essential oils for the skin barrier properties: In vitro, ex vivo and clinical studies.

OBJECTIVE: To evaluate the safety and the synergistic effects of tea tree, lavender, eucalyptus and tangerine essential oils in combination on the skin using in vitro, ex vivo and clinical studies. METHODS: The phototoxicity was predicted using 3T3 neutral red uptake phototoxicity test (OECD TG 432). Skin penetration was evaluated by confocal Raman microspectroscopy using direct application of essential oils to pig ears. For the clinical studies, 40 participants were enrolled and randomized in three groups: (1) lavender, eucalyptus and tangerine, (2) the same essential oils plus melaleuca and (3) placebo group. The skin was evaluated by noninvasive techniques before and after a 90-day period of topical use. RESULTS: The essential oils were non-phototoxic, but the tangerine oil showed dose-dependent cytotoxicity (IC50: 33.1 µg/ml), presenting 35% of penetration in the viable epidermis. On the contrary, 17.7 µg/ml in combination was applied per day in the clinical study and the penetration rate for the combinations (10%, 1.77 µg/ml achieving the viable epidermis) guaranteed the safety, since in the clinical study, the application of the four essential oils improved skin barrier and morphologic skin characteristics, as well as increased skin hydration and decreased sebum levels, with no unwanted effects reported. CONCLUSIONS: All essential oils studied were considered non-cytotoxic or non-phototoxic separately except tangerine, which present a dose-dependent cytotoxicity. Finally, the essential oils in combination in an appropriate amount were safe and effective in the improvement of the hydrolipidic balance and morphological properties of the skin.

OBJECTIF: évaluer la sécurité d'emploi et les effets synergiques des associations d'huiles essentielles d'arbre à thé, de lavande, d'eucalyptus et de mandarine sur la peau à l'aide d'études in vitro, ex vivo et cliniques. MÉTHODES: la phototoxicité a été prédite avec le test de phototoxicité de fixation du rouge neutre 3T3 (OCDE TG 432). La pénétration cutanée a été évaluée par microspectroscopie confocale de Raman grâce à l'application directe d'huiles essentielles sur les oreilles de cochons. Pour les études cliniques, 40 participants ont été inclus et randomisés dans trois groupes : (1) lavande, eucalyptus et mandarine, (2) les mêmes huiles essentielles plus melaleuca et (3) un groupe placebo. La peau a été évaluée par des techniques non invasives avant et après une période d'utilisation topique de 90 jours. RÉSULTATS: les huiles essentielles se sont avérées non phototoxiques, mais l'huile de mandarine a montré une cytotoxicité dose-dépendante (CI 50 : 33,1 µg/ml), représentant 35 % de pénétration dans l'épiderme viable. À l'inverse, dans l'étude clinique, une quantité de 17,7 µg/ml par jour en association a été appliquée, et le taux de pénétration des associations (10 %, soit 1,77 µg/ml atteignant l'épiderme viable) a garanti la sécurité d'emploi, puisque dans l'étude clinique, l'application des quatre huiles essentielles a amélioré la barrière cutanée et les caractéristiques morphologiques de la peau, et a entraîné une augmentation de l'hydratation cutanée et une diminution des taux de sébum, sans signalement d'effets indésirables. CONCLUSIONS: chacune des huiles essentielles étudiées a été considérée comme non cytotoxique ou non phototoxique, à l'exception de la mandarine, qui présente une cytotoxicité dose-dépendante. Enfin, l'association d'huiles essentielles en quantité appropriée a démontré sa sécurité d'emploi et son efficacité dans l'amélioration de l'équilibre hydrolipidique et des propriétés morphologiques de la peau.

Skin photoaging in young men: A clinical study by skin imaging techniques.

OBJECTIVE: Differences in skin physiology and lifestyle among people can influence the skin damage caused by solar radiation. Photoprotection habits play an important role to prevent skin photoaging. Thus, the objective of the present study was to evaluate the skin changes resulting from solar exposure in young men by skin imaging techniques. METHODS: Twenty-three male, aged 18-28 years, with and without photoprotection habits participated in the study. Instrumental measurements in terms of dermis thickness and echogenicity (20 mHz ultrasound - DermaScanC® ), morphological and structural skin characterization (Reflectance Confocal Microscopy - VivaScope® 1500) and high-resolution imaging (Visioface® ) were performed in the malar region of the face. RESULTS: Pigmentation disorders, telangiectasia, wrinkles and lower dermis echogenicity were observed in the skin of subjects without photoprotection habits. Reflectance Confocal Microscopy images showed an irregular honeycomb pattern (35%), polycyclic papillae (40%) and coarse collagen fibres (35%), which are related to photoaging. CONCLUSION: Sun exposure without photoprotection results in a loss of dermal echogenicity and changes in the epidermis structure and collagen fibres regardless of chronological age. Thus, the study adds data for a discussion about correct photoprotection habits among young people and can help to increase the use of sunscreens for male public.

OBJECTIFS: Les différences de physiologie cutanée et de mode de vie peuvent influer sur les lésions cutanées causées par le rayonnement solaire. Les habitudes de photoprotection jouent un rôle important dans la prévention du photovieillissement cutané. Dans ce contexte, l'objectif de l'étude était d'évaluer les changements cutanés résultants de l'exposition au soleil chez les jeunes hommes à l'aide de techniques d'imagerie cutanée. MÉTHODES: L'étude a inclus 23 hommes, âgés de 18 à 28 ans, avec et sans habitudes de photoprotection. Des mesures instrumentales d'épaisseur et d'échogénicité du derme (échographie 20 mHz - DermaScanC®), de caractérisation morphologique et structurale de la peau (Reflectance Confocal Microscopy - VivaScope® 1500) et des images haute résolution (Visioface®) ont été réalisées dans la région malaire du visage. RÉSULTATS: Des troubles de la pigmentation, des télangiectasies, des rides et une moindre échogénicité du derme ont été observés sur la peau d'individus sans habitudes de photoprotection. Les images de microscopie confocale à réflectance ont montré un motif en nid d'abeille irrégulier (35%), des papilles polycycliques (40%) et des fibres de collagène épaisses (35%), qui sont liés au photovieillissement. CONCLUSION: L'exposition au soleil sans photoprotection entraîne une perte d'échogénicité cutanée et des modifications de la structure de l'épiderme et des fibres de collagène, quel que soit l'âge chronologique. Enfin, l'étude agrège les données pour une discussion sur les bonnes habitudes de photoprotection chez les jeunes et peut aider à augmenter l'utilisation des écrans solaires par le public masculin.

Corrigendum: Use of Advanced Imaging Techniques for the Characterization of Oily Skin.

[This corrects the article DOI: 10.3389/fphys.2019.00254.].

Influence of vegetable oils in the rheology, texture profile and sensory properties of cosmetic formulations based on organogel.

OBJECTIVE: The knowledge about how ingredients in formulation can influence the texture profile is an important factor on the development of a cosmetic product. In this context, the aim of this work was to evaluate the effect of vegetable oils in the texture profile, rheological and sensorial properties of cosmetic formulations based on organogel. METHODS: Four organogel-based emulsions were developed and supplemented or not with sunflower, macadamia or olive oils. Analyses of rheological behaviour, texture profile and sensory properties were performed. RESULTS: The vegetable oils added to formulation did not alter the pseudoplastic rheological behaviour, but increased the area of hysteresis and reduced the work of shear of the formulations. In addition, the sunflower seed oil increased the consistency index and all texture parameters while the macadamia oil reduced firmness and consistency. The cosmetic formulation based on organogel containing the sunflower seed oil showed the highest score on sensory evaluation. CONCLUSION: The vegetable oils affected the rheology behaviour, texture profile and sensory properties of the formulations under study. However, the influence of sunflower oil in organogel-based cosmetic formulation was more pronounced considering texture profile and the response perceived by subjects in the sensorial analysis.

OBJECTIF: Les connaissances sur la manière dont les ingrédients d'une formulation peuvent influencer la texture constituent un facteur important dans la conception d'un produit cosmétique. Dans ce contexte, l'objectif de ce travail était d'évaluer l'effet des huiles végétales sur la texture, les propriétés rhéologiques et sensorielles des formulations cosmétiques à base d'organogel. MÉTHODES: Quatre émulsions à base d'organogels ont été préparées et enrichies ou non d'huiles de tournesol, de macadamia ou d'olive. Le comportement rhéologique, la texture et les propriétés sensorielles ont été analysés. RÉSULTATS: Les huiles végétales ajoutées à la formulation n'ont pas altéré le comportement rhéologique pseudoplastique, mais ont augmenté la surface du cycle d'hystérésis et réduit l'effet lissant des formulations. En outre, l'huile de tournesol a augmenté l'indice d'onctuosité et tous les paramètres de la texture, tandis que l'huile de macadamia a réduit la fermeté et l'onctuosité. La formulation cosmétique à base d'organogel contenant l'huile de tournesol a obtenu le meilleur score lors de l'évaluation sensorielle. CONCLUSION: Les huiles végétales ont affecté le comportement rhéologique, la texture et les propriétés sensorielles des formulations étudiées. Cependant, l'influence de l'huile de tournesol dans la formulation des cosmétiques à base d'organogel était plus prononcée compte tenu de la texture et de la réaction perçue par les sujets lors de l'analyse sensorielle.

Correlations between sebaceous glands activity and porphyrins in the oily skin and hair and immediate effects of dermocosmetic formulations.

BACKGROUND: Oily skin and hair not only contain a large amount of sebum, but also exhibit other changes that compromise their physiology. The immediate effects of dermocosmetics are very important for adhesion to treatment. AIM: The aim of the present study was to characterize oily skin and scalp, to evaluate the correlation of sebum production with porphyrin counts and the immediate effects of topical formulations for sebum control. PATIENTS/METHODS: A total of 100 women aged 18-49 years were recruited. Sebaceous gland activity, sebum amount, stratum corneum water content (SCWC) transepidermal water loss (TEWL), skin gloss, amount of porphyrins and pores were determined in the face and SCWC, sebum amount, porphyrin count, and TEWL were also determined in the scalp. The immediate effects of formulations containing a guarana extract were determined after 2 hours of application. RESULTS: A correlation between sebaceous gland activity and presence of porphyrins in the frontal region of the face was detected. Low gloss values and large amounts of pores in the malar region were related to lower skin uniformity. High sebum values and low SCWC and porphyrin count were also observed in the vertex region. The studied formulations reduced the sebum content of face and scalp after 2 hours of application. CONCLUSION: Oily skin and hair showed high sebum values, which were correlated with porphyrin count and with the activity of sebaceous glands. Finally, the studied formulations had immediate reducing effects on sebum amounts on the skin and scalp.

Brazilian and French sensory perception of complex cosmetic formulations: a cross-cultural study.

OBJECTIVE: Brazil and France are two major beauty markets worldwide. Despite this, there is not much cross-information on sensory analysis of cosmetic products between both population of these countries. The objective of this study was to compare the sensory perception of cosmetic formulations between Brazilian and French assessors and establish cross-culturally preferences. METHODS: For this, a total panel of 100 consumers of cosmetics evaluated four different products. The same protocol for the sensory analysis was followed in both countries. RESULTS: The panellists were able to perceive differences in the products and the method proved to be repeatable in both countries. The presence of UV filters in the formulation was noticed and displeased both populations. Brazilians, although dissatisfied with the sensory aspect of the sunscreen, are willing to use it for its UV protection. CONCLUSION: This work delivers important information on the sensory perception of cosmetics by people from different countries and brings important knowledge to develop products with textural properties that will be appreciated worldwide.

OBJECTIFS: Le Brésil et la France sont deux pays majeurs pour le marché de la beauté. Malgré cela, il y a peu d'étude interculturelle sur la perception sensorielle des produits cosmétiques entre ces deux populations. L'objectif de cette étude était donc de comparer l'analyse de formules cosmétiques par deux jurys, l'un brésilien et l'autre français, et d'établir leur préférence. METHODES: Pour cela, nous avons demandé à 100 consommateurs au total d'évaluer 4 produits cosmétiques différents. Le même protocole d'analyse sensorielle a été scrupuleusement suivi dans les deux pays. RESULTATS: Les évaluateurs ont été capables de percevoir des différences significatives entre les produits, et de façon répétable dans chaque pays. Chaque jury a noté la présence de filtres UV dans les formules et ces dernières ont été peu appréciées. Cependant, le jury brésilien était favorable à leur utilisation pour se protéger des UV, et ce malgré leurs propriétés sensorielles insatisfaisantes. CONCLUSION: Ce travail fournit des informations indispensables sur la perception sensorielle des produits cosmétiques par des populations différentes, ainsi que de nouvelles connaissances pour développer des formules avec des textures qui pourront être appréciées à travers le monde.

Use of Advanced Imaging Techniques for the Characterization of Oily Skin.

Excessively oily skin leads to clinical signs that cause discomfort to patients, such as excessive shine, enlarged pores, acne, and an imbalance of the hydrolipidic layer. In this context, a constant demand for the research and development of products that prevent these features, has been noted in the field of cosmetics and dermatology. Thus, the objective of this study is to evaluate the cutaneous characteristics of oily skin due an excessive production of sebum through biophysical and skin imaging techniques. 19 participants with different skin types were selected and the following parameters were evaluated: pore count, determination of the number of sebaceous glands and amount of sebum in infundibulum, determination of cutaneous microrelief, count of comedones, evaluation of epidermis thickness, characterization of the cellular, and comedone size and its characteristics. These evaluations were done through biophysical and skin imaging techniques. The obtained results showed that different regions of the face presented different characteristics related to oiliness, quantity, and the appearance of pores and comedones. The malar region had a lower epidermis thickness and a larger number of large pores. Moreover, in this region excessive sebum production, which can be related to pores, not comedones, was noted. The nose region presented higher sebum content in the infundibulum and lower active sebaceous glands, showing a higher activity of sebaceous production in this region. The chin region presented a positive correlation between the sebum content, roughness parameter and the number of pores and comedones. As different skin properties are related and influence the appearance of undesirable clinical signs, we identified the need for a multifactorial approach for the effective treatment of oily skin. The rational development of multifunctional cosmetic products that promote the control of oily skin, that regulate the keratinization process, improve the microrelief and leads to a better epidermis and dermis structure, will not only improve oily skin conditions but will also allow for the reduction or disappearance of clinical signs that result from excessive oiliness, all of which causes concern and results in a relentless search for cosmetic and dermatological products that address the unaesthetic nature of these conditions.

Topical application and oral supplementation of peptides in the improvement of skin viscoelasticity and density.

BACKGROUND: The combination of oral supplementation and topical formulations to the improvement of skin conditions has been proposed as an innovative approach to obtain effective treatments. However, studies comparing the effectiveness of each type of treatments are still in lack. This way, the objective of this work was to evaluate the clinical efficacy of a dermocosmetic formulation with di- and tripeptides, as well the effects of an oral supplementation based on hydrolyzed collagen through biophysical and skin imaging techniques. METHODS: Sixty healthy female subjects, aged between 40 and 50 years, were enrolled, being separated in 3 groups: topical formulation, oral supplementation, and oral placebo. The stratum corneum water content, skin viscoelasticity, dermis echogenicity, and skin pores parameters were evaluated. RESULTS: The group with the topical formulation showed a significant increase in the stratum corneum water content and skin elasticity after 28-day period and also acted in the dermis echogenicity after 90 days with the formulation with peptides. The oral supplementation acted on skin elasticity and presented a more pronounced effect on dermis echogenicity, reducing skin pores after 90-day period. CONCLUSION: The obtained results with oral supplementation and topical application of hydrolyzed proteins were considered complementary in the improvement of general skin conditions, acting in different mechanisms.

Interactions between UV filters and active substances in emulsion: Effect on microstructure, physicochemical and in-vivo properties.

The objective of the present study was to develop, characterize and evaluate the clinical efficacy of topical formulations containing or not active substances and UV-filters, separate and in combination. To this end a stable formulation was developed to which four aqueous active substances and four lipophilic UV-filters were added. The formulations were then submitted to microscopic characterization by light microscopy, to particle size measurement, and to macroscopic characterization by rheology and texture analysis. Finally, a clinical efficacy study was conducted to determine the effect of the formulations on the skin after application for 1 h. The formulation containing UV-filters showed a high polydisperse microstructure and a large amount of liquid crystals. The formulations containing active substances showed higher resistance to deformation, compression and penetration tests. Regarding spreadability, formulations containing UV filters alone or in combination with active substances showed higher resistance to spreading. This behavior was associated with greater clinical efficacy in terms of stratum corneum water content, protection of the skin barrier function and skin surface brightness. It was demonstrated that the efficacy of the formulation is mainly associated with its structure and the way it interacts with the skin surface. Finally, this study showed that the mixture of these ingredients for the development of multifunctional sunscreens improves the performance of the formulations.

Photoprotective Effects of a Multifunctional Hair Care Formulation Containing Botanical Extracts, Vitamins, and UV Filters.

The aim of this study was to develop and evaluate the efficacy of a multifunctional hair care formulation-Hair BB Cream-containing botanical extracts of Camellia sinensis, Vitis vinifera, and Euterpe orleacea, vitamins, amino acids, UV filters, and silicones for hair treatment and prevention of UV damages. The in vitro antioxidant activity of the botanical extracts was evaluated using the DPPH and chemiluminescence methods. A tensile test, combability, shine, and image analysis were performed to evaluate the efficacy of the formulation. To evaluate protection against UV damage, the hair strands were submitted to UV radiation without and with the application of the Hair BB Cream. The results showed that the application of the Hair BB Cream promoted a reduction in combability values and an increase in break stress and gloss values. After exposure to UV radiation, the hair treated with the BB Cream formulation showed no difference in the mechanical properties test, indicating protection against UV damage. In conclusion, the multifunctional formulation showed several benefits of single product acting in the prevention of UV damage and the treatment of hair damage. Thus, the Hair BB Cream proposed can be suggested as an effective multifunctional hair care product.

Design and Characterization of Topical Formulations: Correlations Between Instrumental and Sensorial Measurements.

The interaction between cosmetic emulsions and the skin's surface is an important factor to consider in the development of topical formulations. Two important ingredients in cosmetic formulations are waxes and polymers. The physical and mechanical properties of formulations directly impact the interface skin-formulation. To evaluate this interaction, it is important to study the rheology, texture, and sensory properties. In this context, the aim of the study was to evaluate the influence of waxes and polymers on the rheological behavior, texture profile, and sensorial properties of topical formulations and the correlation between these parameters. The best combination of a wax and a polymer was determined by full factorial design of experiments and applied to develop eight formulations that were tested in relation to rheological, mechanical, and sensorial properties. The polymer helps with the spreadability of the formulation, and the wax had a strong influence on the parameters related to the structure of emulsions. A correlation between these parameters was observed. This way, it was possible to compare theoretical and practical data, except between the flow index and the work of shear. Finally, it was possible to predict sensorial aspects from rheological and texture parameters, making the formulation process easier and more integrated with all stages of the development of new topical formulations. Thus, the present study introduces a new proposal in the development of cosmetics.

Influence of visible light on cutaneous hyperchromias: Clinical efficacy of broad-spectrum sunscreens.

INTRODUCTION: Cutaneous hyperchromias are disorders of skin pigmentation involving increased melanin production and its irregular accumulation in skin cells. The use of sunscreens is fundamental for the control of hyperchromias by reducing the stimulation of pigmentation, as melanin synthesis is mainly stimulated by solar radiation. Many studies have demonstrated that visible light can induce significant skin damage. Considering the effects of visible light, effective photoprotection should not be limited only to UV protection but should also involve visible and infrared protection. OBJECTIVE: The aim of this study was to evaluate the efficacy of UV-VIS sunscreens in protecting skin against damages caused by solar radiation and the influence of visible light on the appearance of cutaneous hyperchromias. METHODS: Forty volunteers aged 18 to 39 years with skin hyperpigmentation participated in the study. To evaluate the efficacy of the formulations developed, the percentage of hyperpigmented area was evaluated using high-resolution images-Visioface® Quick (Courage-Khazaka, Germany) and the analysis of epidermal pigmentation was performed by RCM-Vivascope® 1500 (Lucid, USA). Also, the melanin index was determined using the Mexameter® M X16 colorimeter (Courage-Khazaka, Germany). RESULTS: The developed formulations were effective in the reduction in melanin index, epidermal pigmentation, and percentage of hyperpigmented area. CONCLUSION: Finally, this study discusses how the combination of UV filters and pigments can protect the skin from solar radiation and reduces skin hyperpigmentations.

Development of a HPLC method for determination of four UV filters in sunscreen and its application to skin penetration studies.

This study describes the development, validation and application of a high-performance liquid chromatography (HPLC) method for the simultaneous determination of the in vitro skin penetration profile of four UV filters on porcine skin. Experiments were carried out on a gel-cream formulation containing the following UV filters: diethylamino hydroxybenzoyl hexyl benzoate (DHHB), bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) and ethylhexyl triazone (EHT). The HPLC method demonstrated suitable selectivity, linearity (10.0-50.0 µg/mL), precision, accuracy and recovery from porcine skin and sunscreen formulation. The in vitro skin penetration profile was evaluated using Franz vertical diffusion cells for 24 h after application on porcine ear skin. None of the UV filters penetrated the porcine skin. Most of them stayed on the skin surface (>90%) and only BEMT, EHT and DHHB reached the dermis plus epidermis layer. These results are in agreement with previous results in the literature. Therefore, the analytical method was useful to evaluate the in vitro skin penetration of the UV filters and may help the development of safer and effective sunscreen products.

Antioxidant-based topical formulations influence on the inflammatory response of Japanese skin: A clinical study using non-invasive techniques.

Cutaneous irritants exposure induces an excess of ROS in the skin and can ensue an inflammatory response. Topical antioxidant-based formulations can help to counteract ROS generation. This study evaluated the influence of antioxidant-based topical formulations on the inflammatory response of skin, using a combination of in vivo real-time non-invasive techniques. Nine test areas were defined on each volar forearm of the 25 Japanese volunteers. Measurements were performed before and after treatment with 15µL of a 5% sodium dodecyl sulfate solution and 15µL of the same based formulation or the vehicle with 1% of the antioxidants. Volunteers without antioxidant treatment showed more pronounced erythematous areas. Transepidermal water loss of areas treated with green tea polyphenol (GTP)-based formulation showed fully recovered skin. Skin barrier damage caused by repeated applications of SDS showed characteristic alterations, detectable by in vivo confocal microscopy such as desquamation, spongiosis and inflammatory infiltrates. The majority of confocal microscopy inflammation signs were found in skin without treatment followed by the vehicle. Ascorbyl tetraisopalmitate, Coenzyme Q10, GTP- and Resveratrol-based formulations reduced the anti-inflammatory cytokines release and attenuated inflammatory signs. The combination of techniques provides results that highlight the importance of antioxidant-based formulations for rapid skin recovery.

Assessment of skin pigmentation by confocal microscopy: Influence of solar exposure and protection habits on cutaneous hyperchromias.

BACKGROUND: Cutaneous hyperchromias are disorders of skin pigmentation involving an increase of melanin production and its irregular accumulation in skin cells. It is known that the use of sunscreens helps to prevent changes in the skin pigmentation pattern, but the structural and morphological alterations that occur in the different types of hyperpigmentations need better elucidation. OBJECTIVE: To assess the influence of solar exposure and protection habits on the pattern of skin pigmentation using reflectance confocal microscopy (RCM). METHODS: Forty volunteers aged 18-39 years with skin hyperpigmentation participated in the study. Skin characterization was performed by imaging techniques and by assessing the habits of solar exposure and protection by applying questionnaires to the volunteers. RCM was used to record sequences of confocal sections at areas of interest and to examine cell shape and brightness in the basal cell layer of the lesion and in normal perilesional skin. Furthermore, high-resolution images were obtained for analysis of the spots. RESULTS: Sunlight influences the number and location of spots as the face of volunteers with higher solar exposure was covered with spots, whereas volunteers with less exposure had fewer spots located in the nose and cheeks region due to greater exposure of these areas to the sun. CONCLUSION: The data showed the importance of sun protection for preventing changes in the pattern of skin pigmentation, and RCM proved to be an important tool for skin characterization.