Fabrication of matrix–structured monodisperse microspheres through the break–up of a flow–focused laminar water–in–oil emulsion jet
Many applications such controlled drug release, food flavouring, 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 with controlled attributes, i.e. structured particles with a very narrow size distribution, or structured monodisperse “designer” particles.
This study 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. The technology is capable of producing monodisperse microspheres in the size range of 10 to 200 microns with near 100% encapsulation efficiencies. It is particularly suitable for the production of particulate systems of the delivery of water-soluble drug compounds.