Assessment of skin barrier function using mathematical modeling of TEWL-desorption curves: age related differences
Palavras-chave: barrier function, POST, TEWL, ageing.
ResumoThe study aimed to investigate changes in the cutaneous barrier function caused by ageing using the POST (plastic occlusion stress test) methodology followed by mathematical modeling of the TEWL data obtained after removal of the occlusion. 32 healthy volunteers participated in the study. They were separated into two groups: one of volunteers under and the other of subjects over 30 years old. An occlusive patch was applied to the ventral forearm of each volunteer for 2 hours. After removal of the patch, the TEWL was measured for 30 minutes. A bi-compartmental mathematical model was fitted to the data and t1/2evap – evaporation half-life- and DWM – dynamic water mass- were calculated. Discrete differences were found between the kinetic parameters obtained for the two groups, which seems to indicate that the water balance and skin barrier were not severely altered in the age ranges included in the study. Nevertheless, the desorption curves of the under 30 volunteers presented a sharp decay, whereas in senile skin the decay occurred at a much slower pace. It can be concluded that the dynamic methodology was able to establish a mild differences in the water dynamics of aged skin, which can potentially be applied to the efficacy and safety testing of skin products.
Ciências Biofarmacêuticas / Biopharmaceutical Sciences