Conclusions
In a highly competitive market, end-user involvement has become an important factor in the product design process, as the sensory interactions heavily affect their perception and the assessment of the product. We have proposed an optimization-based methodology for the design of formulated products, which incorporates the assessment of consumer preferences along with available property models and heuristic rules to generate alternative formulations. The methodology was illustrated with two skin moisturizer products and using a commercial product as a reference for each case. A series of alternative solutions with minimum ingredient costs were generated and then manufactured and evaluated. The alternatives generated taking into account the full set of information, including the heuristics update from the consumer assessment data, were shown to be more similar to the reference products. The comparison was made through optical microscopy observations, evaluation of rheological and textural properties, and the measurement of the white residues left during rub-out.
As this methodology involves the participation of untrained consumers, it is possible to reduce the time and resources spent in cosmetic emulsions design compared with sensorial panels, as there is no panel training involved. The methodology permits us to interpret the answer to the products according to how they are perceived and calculate the importance and the interaction of the evaluated attributes, which makes it valuable to the formulator. This suggests that this is a useful methodology not only to formalize the information about consumers’ perception of cosmetic products but also to guide the generation of alternatives for other formulated products.