Fotoestabilização de protectores solares por incorporação de chás como fase externa
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Data
2015
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Edições Universitárias Lusófonas
Resumo
A utilização de filtros ultravioleta (UV) isolados em formulações fotoprotetoras origina produtos com proteção limitada contra
as radiações, evidenciando a necessidade de desenvolver formulações contendo a associação de filtros UVA e UVB. No entanto,
a maioria das formulações desenvolvidas por combinação destes filtros é instável como consequência desta combinação, bem
como pela exposição à radiação UV. Assim, é fundamental associar activos que permitam a sua fotoestabilização. O chá é a
segunda bebida mais consumida em todo mundo e representa uma fonte nutritiva de compostos bioactivos, nomeadamente
polifenóis, que fornecem actividade antioxidante. No presente trabalho pretendeu-se desenvolver e avaliar formulações
contendo chá verde ou chá preto e contendo os filtros solares avobenzona (filtro solar UVA) e octilmetoxinamato (filtro solar
UVB), no sentido de as tornar fotoestáveis e eficazes, proporcionando amplo espectro de fotoprotecção. Estas formulações
foram desenvolvidas com substituição total da fase externa da emulsão óleo/água (O/A) por estes chás. Os resultados obtidos
permitiram concluir que ambos os chás apresentaram capacidade fotostabilizadora, com especial foco para o chá verde nas
condições de armazenamento à temperatura ambiente e a 5 °C, e para o chá preto nas amostras armazenadas a 40 °C.
The use of isolated ultraviolet (UV) filters in photoprotective formulations creates products with limited protection against radiation, emphasising the need to develop formulations containing UVA and UVB filter combinations. However, most of the formulations developed to include both filters are unstable as a result of this combination, as well as by exposure to UV radiation. It is, therefore, crucial to include additives that enable photostabilization. Tea is the second most widely consumed beverage in the world and represents a good source of bioactive compounds, particularly polyphenols, which provide antioxidant activity. In the present work formulations containing green tea or black tea, as well as the sunscreens avobenzone (UVA sunscreen) and octilmetoxinamato (UVB sunscreen), were developed and evaluated in order to develop new and effective photostable formulations providing broad spectrum photoprotection. These formulations have been developed with complete replacement of the external phase of the oil in water (O/W) emulsion by these teas. The results showed that both teas presented photostabilizing capacity, particularly for green tea in the storage conditions at room temperature and at 5 °C, and black tea for the samples stored at 40 °C.
The use of isolated ultraviolet (UV) filters in photoprotective formulations creates products with limited protection against radiation, emphasising the need to develop formulations containing UVA and UVB filter combinations. However, most of the formulations developed to include both filters are unstable as a result of this combination, as well as by exposure to UV radiation. It is, therefore, crucial to include additives that enable photostabilization. Tea is the second most widely consumed beverage in the world and represents a good source of bioactive compounds, particularly polyphenols, which provide antioxidant activity. In the present work formulations containing green tea or black tea, as well as the sunscreens avobenzone (UVA sunscreen) and octilmetoxinamato (UVB sunscreen), were developed and evaluated in order to develop new and effective photostable formulations providing broad spectrum photoprotection. These formulations have been developed with complete replacement of the external phase of the oil in water (O/W) emulsion by these teas. The results showed that both teas presented photostabilizing capacity, particularly for green tea in the storage conditions at room temperature and at 5 °C, and black tea for the samples stored at 40 °C.
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PELE, SKIN, PRODUTOS COSMÉTICOS, COSMETICS, RADIAÇÃO ULTRAVIOLETA, ULTRAVIOLET RADIATION, CIÊNCIAS FARMACÊUTICAS, PHARMACEUTICAL SCIENCES, PROTETORES SOLARES, SUNSCREENING AGENTS, ESTUDOS DE CASO, CASE STUDIES, CHÁ, TEA