Efficacy Evaluation of Different Cream Formulations on Healthy Skin Properties

In this study three cream formulations were compared in order to assess the influence of different kind of excipients on the skin barrier and stratum corneum hydration. The first cream was formulated based on lipophilic emollients: petrolatum, paraffin oil, cetylstearilic alcohol, cetyl palmitate and paraffin, the second cream was formulated based on emollients (cetylstearilic alcohol, cetyl palmitate) and humectants (urea and glycerin), both as oil-in-water emulsions, and the third cream contained emollients (paraffin oil, cetyl palmitate, cetylstearilic 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 ± 2C) and 45% ± 2% relative humidity. Skin conditions in terms of water content of the stratum corneum and transepidermal water loss (TEWL) were analyzed before creams application and at several time-intervals after cream application, during 4 hours. The best hydration was obtained when the multiple emulsions were used and also the duration of hydration was the greatest. The TEWL values are not significantly influenced by the studied formulations. Rezumat În acest studiu s-au comparat trei formulări de creme pentru a evalua influenţa diferiţilor excipienţi asupra barierei pielii şi asupra hidratării stratului cornos. Prima cremă s-a formulat pe bază de emolienţi lipofili: vaselină, ulei de parafină, alcool cetilstearilic, palmitat de cetil şi parafină; în a doua formulare s-au asociat emolienţi alcool cetilstearilic, palmitat de cetil – şi umectanţi – uree şi glicerol. Ambele formulări sunt emulsii de tip ulei în apă. A treia cremă s-a formulat ca emulsie multiplă, asociind emolienţi – ulei de parafină, alcool cetilstearilic, palmitat de cetil şi umectanţi – uree şi glicerol. Cele trei formulări au fost testate pe 10 voluntari sănătoşi. S-a înregistat hidratarea stratului cornos şi pierderea de apă transepidermică, măsurătorile fiind efectuate la temperatura camerei (22 ± 2C) şi la o umiditate relativă de 45% ± 2%, înainte de aplicarea cremelor şi la diferite perioade de timp după aplicare. Emulsia multiplă a determinat cea mai bună hidratare a stratului cornos, la toţi timpii evaluaţi. Valorile pierderii de apă transcutanate nu au fost influenţate semnificativ de cele trei formulări studiate.