Water in Oil W/O Pickering Emulsion Encapsulated in Oil in Water O/W Emulsion: A Double Emulsion for Poorly Soluble Drugs

Abstract

There are two problems that hinder the use of double emulsions in pharmacies: large-scale equipment not available for one-step emulsification and obtaining a double emulsion and limited ingredients available to replace the tensionactive agents as primary emulsifier because these surfactants are toxic. To overcome these difficulties, a two-stage emulsification strategy has been developed, first generating a water-in-oil Pickering emulsion stabilized by magnesium oxide particles and then the double W/O/W emulsion, thereby reducing significantly the amount of voltage-active. 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". The Bancroft rule served as a model for the formulation. The emulsification was carried out using a rotor stator mixer. The stability of these emulsions has been studied using several parameters (pH, conductivity, droplet size, dye test). The dye test and the conductivity measurement confirmed the W/O nature of the emulsion and W/O/W nature of the double emulsion. This study showed that we were able to develop a saturated double W/O/W emulsion.