Abstract

Background: The search for treatments of cutaneous alterations caused by the aging process has
motivated the cosmetic area to develop innovative products, which led to intense research for new
active ingredients with the potential to bring unique benefits to the skin. Using natural active substances to develop cosmetic products with proven stability and clinical efficacy is an essential topic for the cosmetic area today. The objective of this study was to develop and evaluate the stability, sensorial properties, and clinical efficacy of photoprotective cosmetic formulations containing Spirulina dry extract using advanced biophysical and skin imaging techniques.

Materials and Methods: After developing photoprotective formulations added or not 0.1% of Spirulina, the rheological behavior, sensory properties, and short and long term clinical studies were carried out. The efficacy studies evaluated transepidermal water loss (TEWL), stratum corneum water content, sebum content, skin micro-relief, dermis echogenicity and thickness, and structural and morphological analysis of the epidermis parameters in the face region before and after the application of the formulations.

Results: The rheological behavior and sensory properties were adequate to the objective of the study. Furthermore, there was an increase in hydration and control of sebum content after the short time of clinical evaluation. Improvements in skin hydration, barrier function, microrelief, dermis thickness, and depth of papillae were noted in the long-term clinical studies.

Conclusions: The present study highlights the importance of stable development, with proper sensory properties and clinically proven efficacy photoprotective cosmetic formulations containing natural ingredients, like Spirulina, which can bring multiple benefits to the skin, being a complete treatment to the consumer.