Pickering emulsions are surfactant-free emulsions, stabilized by colloidal particles. These systems are experiencing renewed interest on the one hand, because it is preferable to limit the use of synthetic surfactants for ecological reasons, and on the other hand, because the functionalization of particles has undergone recent advances.

It is possible to make very simple calibrated emulsions of controlled size, exploiting a phenomenon called "limited coalescence".

We have formulated and characterized Pickering water type emulsions in oil stabilized by magnesium oxide particles and containing paracetamol in the internal phase. Bancroft's rules served as a model for the formulation. The emulsification was done by progressive addition of a dispersed aqueous phase in a dispersing oily phase using a turbo rotor-stator mixer. The stability of these emulsions has been studied using several parameters (droplet size, pH, viscosity, conductivity...) and quantitative analysis of active principles by UVvisible spectrophotometry.

The dye test and conductivity measurement confirmed the E/H nature of these emulsions. Droplet size, PH, andviscosity were influenced by the quantities of magnesium oxide particles and the active ingredients used.

The quantitative analysis of paracetamol confirmed its presence in the aqueous phase.

The results showed that we were able to develop a stable Pickering type E/H emulsion with magnesium oxide particles. In addition, we were able to incorporate paracetamol into the dispersed phase.