In this optimization study a mixture experimental design in a
constrained region of interest was used to estimate the model coefficients
in Eq. (1) in order to represent and analyze the response
surfaces obtained on the basis of the experimental trials on the formulations.
The experimental results (two replications plus check
points) are reported in Table 2.
The special cubic models fitted to the experimental data (checkpoints
included after model validation) along with the adjusted R2