Adaptations in the simulated annealing algorithm to generate D-optimal mixing experiments both in the absence and presence of biases in the specification of the proportions.

The mixture designs are represented in terms of variables (xi, i = 1 , · , q ) called by components. The components display an experimental region described in a simplex space, where each variable has values between 0 and 1, portraying the specification of proportions. With these characteristics, the practice of the designs both in several industrial and in pharmaceutical sectors becomes justifiable. The issue is that defining a structure with N experimental points becomes complex since we can generate infinite configurations. Therefore, we used D-optimal mixture designs, which, in summary, guarantee more accurate confidence regions for parameter estimates as we develop these designs conditioned to a statistical criterion. For this reason, we have undertaken this approach to fulfill the aim of this study. We propose a modification in the simulated annealing algorithm combined with the Monte Carlo procedure in the generation of D-optimal mixture designs classified both by the presence and by the absence of bias in the proportion specifications. We conclude that the proposed modification in the simulated annealing algorithm provides the search with generation of D-optimal designs, supporting the control of the distribution of experimental points either near or far from the edges of the observed region limited by the simplex space. The optimal strategies generated in a biased way are less sensitive in relation to the number of components. [ABSTRACT FROM AUTHOR]