A mathematical modeling strategy to predict the spreading behavior on skin of sustainable alternatives to personal care emollients.

Spreadability is one of the most important physicochemical properties of cosmetic products, according to the consumer. Thus, it is fundamental to develop strategies with the aim to improve the knowledge and predict the behavior of alternatives to synthetic emollients. The main goal of this research article was to correlate different physicochemical attributes, namely spreading value, apparent viscosity, density, saponification value, iodine value, peroxide value, acid value and melting range, with the spreading behavior of sustainable alternatives for petrolatum and dimethicone. The sensitivity and adequacy of each parameter were statistically analyzed, and the models were built by forward selection. The two adjusted and optimized models include viscosity and density as parameters and, in the petrolatum case, the model further includes the melting range, which was also validated as a significant predictor. Furthermore, it was also possible to compare the data obtained with the consumer's perception of the spreading behavior of the studied raw materials. A strong correlation was observed, suggesting that these tools mirror the consumer opinion. The application of these mathematical models is a valuable tool to assist the entire replacement process, which usually is a time-consuming procedure.