NI (nonionic) and LC (liquid crystal) emulsions were developed, and their rheological parameters were evaluated. Also, the hydrating effect of NI and LC emulsions was tested among women with 20 ± 2 years, as well as NI emulsions among women with 70 ± 7 years of age. The results showed that the emulsions were stable and they had a pseudoplastic behavior and apparent thixotropy. The data revealed the best rheological profile of the NI emulsion with the lowest pour point (13.57 ± 3.19 Pa) and the highest spreadability (4.99 ± 0.54 mm²/g). There was no significant difference in hydration between NI and LC emulsions (16.0 ± 5.1%; 14.2 ± 5.5%) among younger women. However, hydration among elderly women was of 13.1 ± 5.6% for NI emulsion, revealing that it was significantly lower in this group when compared to the younger one. These data revealed the importance of rheological evaluation as a factor of choice among similar cosmetic formulations. Age bracket selection also proved to be very important in the assessment of skin hydration by cosmetic products.
Emulsion; Skin aging; Skin hydration; Rheology
