LAUSR

Abstract We discuss the production of microcapsules with hydrogel-based shells by ionotropic gelation of gellan gum from monodispersed oil-in-water-in-oil (O/W/O) double emulsion templates obtained using glass-capillary microfluidic devices. An oil extraction step was added after the shell gelation process to enable the dispersion of the microcapsules in an aqueous medium. The proposed approach for producing biopolymer-based microcapsules for hydrophobic agents dispersed in a water phase has a broad range of applications in delivery of hydrophobic compounds dispersed in an aqueous medium. We report the operability window for the production of monodispersed microcapsules as a function of the flow rate of each fluid phase and the dimensions of the device. Microcapsules with mean diameters ranging from 95 to 260 µm and a maximum coefficient of variation of 5% were formed. The results show how to independently control the capsule diameter and shell thickness by varying the outer and middle phase flow rates.