The composition of samples in this mixture DoE is shown in Table . The design was a simplex lattice, with two replicates and one block. The range of concentration was 50.00 -90.00 (% w/w), 10.00 -50.00 (% w/w) and 0.00 -40.00 (% w/w) for cetyl palmitate, Capryol® 90 and butamben, respectively. Raman images acquisition was made in a random order as indicated in Table to avoid bias in the results. The distributional homogeneity index (DHI) and standard deviation of histograms (STD) from Raman images were used as outputs (responses) for the mixture DoE. DHI is a parameter developed in 2014 that is employed to evaluate the homogeneity in images by a macropixels and continuous-level moving block approach . Mixture DoE was created, and results analyzed using Design Expert version 11 (Stat-Ease Inc., Minneapolis, MN, USA).