Research Summary
In this study, three cream formulations were compared to assess the influence of different excipients on the skin barrier and stratum corneum hydration. The first cream was formulated with lipophilic emollients: petrolatum, paraffin oil, cetylstearyl alcohol, cetyl palmitate, and paraffin. The second cream was formulated with both emollients (cetylstearyl alcohol, cetyl palmitate) and humectants (urea and glycerin), as an oil-in-water emulsion. The third cream contained emollients (paraffin oil, cetyl palmitate, cetylstearyl alcohol) and humectants (urea and glycerin) in a multiple emulsion system, water1-oil-water2 type (W1/O/W2), of second order and three components.
The formulations were tested on the forearm of 10 healthy volunteers. The measurements were performed at room temperature (22°C ± 2°C) and 45% ± 2% relative humidity. Skin conditions, in terms of water content of the stratum corneum and transepidermal water loss (TEWL), were analyzed before cream application and at several time intervals after application, over a period of 4 hours.
The results showed that the best hydration was achieved when the multiple emulsions were used, and the duration of hydration was also the longest. However, the TEWL values were not significantly influenced by the studied formulations.
Keywords: moisturizers, skin hydration, transepidermal water loss (TEWL)
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