Cosmetic attributes (oiliness reduction and firmness) from face masks composed of red, green and black clays / Atributos cosméticos (redução de oleosidade e melhora de firmeza) de máscaras faciais compostas por argilas vermelha, verde e preta

The appearance of skin strongly influences people´s self-esteem and well-being. Among the characteristics that affect the most, we can cite acne and wrinkles. Therefore, minimizing those characteristics by using cosmetics has important value for the consumer. Nowadays, there is a demand for natural ingredients, mainly concerning cosmetic products. The use of clays in beauty care is old, with therapeutic uses since Prehistory. There is an essential advantage in using clays for cosmetic purposes, as it is a low-cost, environmentally friendly, natural, and abundant ingredient, which is chemically inert with a low level of toxicity (when in adequate conditions), easy to apply and remove, dries, and hardens fast. In this research work, we aimed at developing and investigating the effect of formulations containing red, green, and black clays as active components in oiliness reduction, and firmness and elasticity improvement in vivo, as well as characterizing clays mineralogically. All clays presented different compositions. Black clay was the one with the simplest mineralogic content, lowest density, and smallest particle size. It was the richest in Si and Al. Green clay presented expandable smectite and the highest density. Red clay presented the largest particle average size and was the richest in iron content. By thermal analysis, clays presented two characteristic events: the water loss (dehydration) and the dihydroxylation of kaolinite, turning into meta kaolinite. In Sebumetry, clays showed a significant reduction of skin oiliness on the forehead in both concentrations after 2h of contact compared to control, baseline, and placebo. However, after 4h (2h after removal), no significant difference was observed with the control. In the Cutometry, clays did not present significant efficacy in skin firmness and elasticity improvement when compared to control and placebo sites, thus, further studies should be performed comparing the efficacy of different vehicles with dispersed clays. Finally, clay mask formulations were developed with black, red, and green clay dispersed in an oil-free gel vehicle, which proved to be adequate for oily skin

A aparência da pele influencia fortemente autoestima e o bem-estar das pessoas. Dentre as características que mais afetam podemos citar acne e rugas. Portanto, minimizar estas características com o uso de cosméticos tem um valor importante para o consumidor. Atualmente existe uma procura por ingredientes naturais, principalmente no que diz respeito a produtos cosméticos. O uso das argilas nos cuidados de beleza é antigo, com usos terapêuticos desde a Pré-História. Há uma vantagem essencial na utilização de argilas para fins cosméticos, pois é um ingrediente de baixo custo, ecologicamente correto, natural, e abundante, que é quimicamente inerte e tem baixo nível de toxicidade (quando usado em condições adequadas), fácil de aplicar e remover, seca, e endurece rapidamente. Neste trabalho de pesquisa, objetivamos desenvolver e investigar o efeito de formulações contendo argilas vermelha, verde e preta como componentes ativos na redução da oleosidade e na melhoria da firmeza e elasticidade in vivo, bem como caracterizar mineralogicamente as argilas. Todas as argilas apresentaram diferentes composições. A argila preta foi a de conteúdo mineralógico mais simples, mais baixa densidade, e menor tamanho de partícula. Foi a mais rica em Si e Al. A argila verde apresentou esmectita expansível e mais alta densidade. A argila vermelha apresentou o maior tamanho médio de partícula e foi a mais rica em ferro. Segundo a análise térmica, as argilas apresentaram dois eventos característicos: a perda de água (desidratação) e a desidroxilação da caulinita, transformando-se em meta-caulinita. Na Sebumetria, as argilas demonstraram significativa redução na oleosidade da pele na testa em ambas as concentrações após 2h de contato comparada ao controle, basal e placebo. Porém, após 4h (2h após remoção), nenhuma diferença significativa foi observada com o controle. Na Cutometria, as argilas não apresentaram Eficácia significativa na melhora da firmeza e elasticidade quando comparadas aos sítios controle e placebo, portanto, mais estudos devem ser realizados comparando a eficácia de diferentes veículos com argilas dispersas. Finalmente, as formulações de máscaras de argilas foram desenvolvidas com argilas preta, vermelha e verde dispersas em um veículo em gel livre de oleosidade, o qual provou ser adequado para pele oleosa

Solid-state properties of pink clay from Jequitinhonha Valley in Brazil for pre-formulation study

Abstract Clay minerals are still widely used in pharmaceutical products for human health and cosmetic purposes. Pre-formulation studies were conducted to identify solid-state properties of pink clay, a sample from Diamantina, Brazil. Among the solid properties to be analyzed, we have selected type identification, iron phases, crystallinity, powder flow characteristics, thermal behavior, and non-isothermal phase transition kinetics. The pink clay is composed of (1:1) clay type and kaolinite as the main component. The Mössbauer spectrum of pink clay shows Fe3+(α-Fe2O3) Clay minerals are still widely used in pharmaceutical products for human health and cosmetic purposes. Pre-formulation studies were conducted to identify solid-state properties of pink clay, a sample from Diamantina, Brazil. Among the solid properties to be analyzed, we have selected type identification, iron phases, crystallinity, powder flow characteristics, thermal behavior, and non-isothermal phase transition kinetics. The pink clay is composed of (1:1) clay type and kaolinite as the main component. The Mössbauer spectrum of pink clay shows Fe3+(α-Fe2O3) hematite, Fe2+, and Fe3+ with large Δ/2ξq of about 2.80 and 2.69 mm.s-1 respectively, related to iron silicates, most likely pyroxene, and a superparamagnetic Fe3+. Pink clay exhibits poor flow properties. The thermal behavior indicates a phase-transition between 400 - 600 ºC associated with the dehydroxylation of the pink clay system requiring ~300 kJ mol-1, being constant until the process reaches a conversion of ~50% when the energy is enhanced to ~530 kJ mol-1, concluding the whole dehydroxylation process (α=80%). Solid-state properties and characteristics found for the pink clay must be considered for the proper design of formulations. This type of clay shows unique pharmaceutical properties that can be favorably exploited by the cosmetic industry