Clay-Based Cosmetic Formulations: Mineralogical Properties and Short-Term Effects on Sebum Regulation and Skin Biomechanics

• 發表在: Cosmetics
• Main Authors: Fernanda Daud Sarruf, Michele Georges Issa, Maria Valéria Robles Velasco, Catarina Rosado, André Rolim Baby
• 格式: Article
• 語言: 英语
• 出版: MDPI AG 2025-10-01
• 主題: clays; sebumetry; cutometry; thermal analysis; mineralogical analysis
• 在線閱讀: https://www.mdpi.com/2079-9284/12/5/219

The growing demand for dermocosmetics with ingredients of natural origin reflects the pivotal role of cutaneous health and appearance in consumer self-esteem. Under this context, clays have attracted attention for their potential applications in dermatological care. Our research work aimed to increase knowledge on the short-term impact of cosmetic formulations containing a blend of red, green, and black clays, assessing their effects on sebum regulation and in cutaneous biomechanical behavior (firmness/elasticity). Unlike daily skincare products, clay masks are used infrequently and for short durations; thus, an in vivo assessment was conducted after a 2-h application to reflect typical consumer use. The mineralogical and physicochemical properties of the different clays were characterized. Mineralogical analysis revealed distinct compositions among the clays: black clay exhibited a simpler mineral profile, lower density, and smaller particle size; green clay contained expandable smectite and was the densest; and red clay displayed the largest average particle size and highest iron content. Thermal analysis identified two major transitions: dehydration and kaolinite dehydroxylation. In vivo studies conducted in participants showed a significant reduction in skin oiliness across all clay-based formulations compared to baseline, control, and placebo following a 2-h application, and the rebound sebum production was dependent on clay concentration. Cutometry measurements did not reveal statistically significant improvements in skin firmness or elasticity compared to the control and placebo. The findings suggested that while clay-based formulations effectively reduced skin oiliness in the short term, their impact on sebum regulation and on skin biomechanical properties was limited after such a short product application period. Additional studies are warranted to elucidate the distinct effects of each clay, assess their behavior in different formulation bases, and evaluate their efficacy after repeated use.