Table 1 Lower and Upper Constraint for each ingredient in oil phase
Oil Lower Constraint (%) Upper Constraint (%)
Rapeseed oil 20 80
Miglyol 20 80
Salmon oil 2 10
Data from the physico-chemical properties were used to calculate the special cubic equation for the three components:
Y=b 1X1 +b 2X2 +b 3X3 +b12X1X2 +b 13X1X3 +b 23X2X3 +b123X1X2X3 (1)
in which Y is the measured response, b(i) are para- meters estimated for each linear and cross-product term in the model, and X1, X2 and X3 represent level consti- tuents of rapeseed oil, miglyol and salmon oil. Table 2 presents the mixture design used for the cos- metic matrix.