A method of producing microparticles using an emulsion based synthesis route including: (i) Providing a first fluid phase and a second fluid phase, wherein the first fluid phase is a continuous phase and the second fluid phase is a dispersed phase comprising a dispersed material, wherein the continuous phase is immiscible with the dispersed phase wherein the continuous phase comprises a surfactant; (ii) Providing a shear device having separate first and second inlets for the first continuous phase and the second dispersed phase, the shear device having a rotor configured to rotate at a rotation speed inside a stationary stator and an annular gap provided between the rotor and stator in which emulsification occurs, the shear device comprising first and second inlet ports wherein the first continuous phase and the second dispersed phase are provided to the shear device via separate inlet ports; (iii) Mixing the first continuous phase and the second dispersed phase in the presence of the surfactant in the shear device to form an emulsion of droplets., the mixing step comprising an emulsifying step wherein the second dispersed phase is emulsified into the first continuous fluid phase in the shear device, wherein droplet diameter and variance of droplet diameter are controllable to produce microparticles of desired diameter by variation of one or more of (a) size of the annular gap provided between the rotor and stator (b) speed of rotation of the rotor (c) dispersed phase volume fraction, (d) a viscosity ratio between phases, (e) continuous phase viscosity; and (f) surfactant concentration; (iv) Controlling the dispersed phase volume fraction during the mixing step by the control of the flow rate at the separate inlet ports to the shear device for the continuous phase and the dispersed phase; (v) Drying the emulsion comprised of droplets to form microparticles the microparticles having one of a spherical, crumpled, dimpled, porous or hollow morphology, and having a coefficient of variance of microparticle diameter of 25% or less, and wherein microparticle diameter size is in the range of 100nm - 1 micron, most preferably 200nm - 1 micron. (i) Providing a first fluid phase and a second fluid phase, wherein the first fluid phase is a continuous phase and the second fluid phase is a dispersed phase comprising a dispersed material, wherein the continuous phase is immiscible with the dispersed phase wherein the continuous phase comprises a surfactant; (ii) Providing a shear device having separate first and second inlets for the first continuous phase and the second dispersed phase, the shear device having a rotor configured to rotate at a rotation speed inside a stationary stator and an annular gap provided between the rotor and stator in which emulsification occurs, the shear device comprising first and second inlet ports wherein the first continuous phase and the second dispersed phase are provided to the shear device via separate inlet ports; (iii) Mixing the first continuous phase and the second dispersed phase in the presence of the surfactant in the shear device to form an emulsion of droplets., the mixing step comprising an emulsifying step wherein the second dispersed phase is emulsified into the first continuous fluid phase in the shear device, wherein droplet diameter and variance of droplet diameter are controllable to produce microparticles of desired diameter by variation of one or more of (a) size of the annular gap provided between the rotor and stator (b) speed of rotation of the rotor (c) dispersed phase volume fraction, (d) a viscosity ratio between phases, (e) continuous phase viscosity; and (f) surfactant concentration; (iv) Controlling the dispersed phase volume fraction during the mixing step by the control of the flow rate at the separate inlet ports to the shear device for the continuous phase and the dispersed phase; (v) Drying the emulsion comprised of droplets to form microparticles the microparticles having one of a spherical, crumpled, dimpled, porous or hollow morphology, and having a coefficient of variance of microparticle diameter of 25% or less, and wherein microparticle diameter size is in the range of 100nm - 1 micron, most preferably 200nm - 1 micron.