Fabrication of matrix-structured microspheres through break-up of a flow-focused laminar water-in-oil emulsion jet

Many applications such as controlled drug release, food flavouring and cosmetic colouring require the packaging of different ingredients into a particulate form to achieve desired end-use performances. However, control or even prediction of powder performances is a well known difficult task. The difficulties are essentially caused by the heterogeneous nature of the particle assembly reflected in the broad distribution of their sizes, shapes and structures. To achieve a better predicability and ultimate control of particle performances, many research efforts have recently been directed towards the production of particles\ud with controlled attributes, i.e. structured particles with a very narrow size distribution, or structured monodisperse "designer" particles. This paper presents an innovative technology for the production of monodisperse designer microspheres. The technology uses a monodisperse water-in-oil-in-water dispersion as templates, generated through the break-up of a flow-focused laminar water-in-oil emulsion jet. The templates are then converted into solid microspheres with a matrix structure by solvent evaporation.\ud The technology is capable of producing monodisperse microspheres in the size range of 20 to 200 microns with near 100% encapsulation efficiencies. It is particularly suitable for the production of particulate systems for the delivery of water-soluble drug compounds