Cosmetic formulations containing high amount of powders are a big
challenge to the formulator and represent one of the most difficult
compounding tasks in the cosmetic field. The problems posed by powders
are due to the difficulty in handling them in the production run and in
matching the selected shades during their production. More than in other
cosmetic emulsions, production technology and the energy provided in
the mixing steps strongly influence the final results in terms of colour
and stability. In this respect things have been improved with silicone-
or amino-acids coated oxides but production difficulties, concerning
the addition or the side predispersion of powders remain to be solved.
We describe the basic evaluations and the development work carried out
with the aim of obtaining stable concentrated dispersions of pigments by
employing a new polymeric dispersant. Such dispersant is a newly
developed surfactant, whose good potential of wetting pigments, that was
already known in other technological fields, was applied to foundations
formulation and to pigment dispersion. Dispersions were prepared with
several coated and uncoated pigments, both iron oxides and titanium
dioxide, with various oils, at variable percentages of the emulsifier,
in order to obtain the most stable suspensions using the lowest amount
of emulsifier. The selected suspensions were used to prepare finished
formulations.