Stimulable, stable and biocompatible W/O/W emulsions for encapsulation and controlled delivery of drugs

Abstract : Foams and emulsions Water-in-oil-in-water (w/o/w) emulsions are promising systems for encapsulation and controlled delivery of drugs. A new amphiphilic copolymer (PDMS-$b$-PDMAEMA) was developed as an emulsifier for preventing the notorious instability of those emulsions and was capable of stabilizing multiple emulsions for more than a year. This polymer is stimuli responsive, allowing the formation in a single mixing step, of direct, inverse and w/o/w emulsions, depending on the pH and ionic strength of the aqueous phase. Consequently, by changing pH, w/o/w emulsions can be destabilized and a compound encapsulated in the internal water phase is released in a controlled way. The use of microfluidic PDMS chips for a better control of the size and the morphology of the emulsions was also studied. The aim is to use this promising system to coencapsulate and protect two molecules of interest for health: catechin, an hydrophilic molecule from green tea, and curcumin, an hydrophobic molecule from turmeric. These two antioxidants have lots of potential health benefits but are very fragile and difficult to deliver: formulating them in a double emulsion will allow to preserve them during storage and should improve the absorption.