Using Mixture Design approach to understand interactions of natural oils and waxes in a lipstick base

The aim of this study was to assess the applicability of the Mixture Design approach to understanding the interactions between different raw materials of natural origin in the lipstick base, with the view of reaching an optimal formulation. The Mixture Design experimental approach (with a commercial software package) was used to assess the effects of different compositions of oil and wax phases on the final characteristics of the lipstick, i.e. break point, softening point and glide. An optimal lipstick formula obtained using this approach was then tested against a commercial benchmark (marketed as natural lipstick), in order to establish its practical relevance in the formulation work.

The use of Mixture Design approach has proven to be very efficient in reducing the number of experiments required to determine the optimal ratio of each ingredient, as well as their mixtures. The accompanying software was able to calculate and predict the responses of experiments that were not carried out, providing an efficient way to detect interactions among ingredients and formulate products to required specifications