Desenvolvimento e avaliação clínica dos efeitos de formulações dermocosméticas contendo dimetilaminoetanol ou acetil hexapeptídeo-3 / Development and clinical evaluation of the effects of dermocosmetic formulations containing dimethylaminoetanol or acetyl hexapeptide-3.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Dimethylaminoethanol (DMAE) and acetyl hexapeptide-3 (AHP) have been used in dermocosmetic formulations for anti-aging purposes. However, few scientific papers are concerned about the effects of these active substances on cutaneous tissue. Thus, the aim of the present study is the development, evaluation of physical stability, safety and clinical efficacy of dermocosmetic formulations containing DMAE and/or AHP. Four formulations based on self emulsifying wax containing batyl alcohol and lecithin or polyethyleneglycol ester, stabilized by hydrophilic polymers (hydroxyethylcellulose or acrylate polymer) were prepared as vehicles. They were supplemented or not with acetyl hexapeptide-3 solution (0.05%) and DMAE acetamidobenzoate to final concentrations of 10% and 9%, respectively, and submitted to preliminary stability tests, followed by the determination of rheological behavior, as well as, sensorial analysis. The formulation containing polyethyleneglycol ester and acrylate polymer (F4), chosen as vehicle for the clinical trials, showed the best stability and sensorial. In these trials, skin compatibility was evaluated after a single product application on the backs of volunteers, as well as, the short (immediate effects) and long term efficacy. To evaluate the immediate effects, skin hydration, viscoelastic properties and skin microrelief were tested in the ventral forearm region, 2 hours after application of the formulations: vehicle (F4), vehicle + DMAE (F4D), vehicle + AHP (F4A) and vehicle + DMAE + AHP (F4AD). Long term effects of the same formulations were evaluated in volunteers by daily applications on the forearm and face. After 2 and 4 weeks of treatment, the same parameters were measured in addition to the determination of skin mechanical properties by its anisotropic characteristics. The results obtained in the clinical study showed that all formulations tested had a very good skin compatibility besides an immediate effect of increasing the stratum corneum water content. On the other hand, only formulations containing the active substances produced a significant decrease in transepidermal water loss (TEWL), in other words, these formulations improved the skin barrier function. Long term studies demonstrated that all formulations promoted an enhancement of the stratum corneum water content when applied on the face but not in the forearm. However, only formulations containing AHP reduced skin anisotropy in the face, ie, there was a significant improvement of the skin mechanical properties due to the use of these formulations. In summary, according to the results obtained, it can be concluded that the developed formulations were stable, safe and effective, since they did not present alterations in their physicochemical properties and did not cause skin irritation. Moreover, the formulations containing AHP or DMAE presented immediate effects by reducing the TEWL and the ones supplemented with AHP reduced the skin anisotropy after 4 weeks of application, significantly improving the skin tone and firmness. Thus, it is suggested that AHP may be considered an effective substance to be used in cosmetic formulations with anti-aging purposes.

ASSUNTO(S)

estabilidade clinical efficacy compatibilidade cutânea dimethylaminoethanol eficácia clínica. acetil hexapeptídeo-3 stability acetyl hexapeptide-3 dermocosmetics dimetilaminoetanol dermocosméticos skin compatibility

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