Coating solution droplet size should be selected relative to the size of particles to be coated. Atomizing air volume and pressure determine droplet size; the higher these values, the smaller the droplets. For small particles (250 μm or smaller) a high atomization pressure may be necessary to attain droplets small enough to avoid the formation of liquid bridges between particles at contact points and thus avoid agglomeration. Droplet size is also a function of coating solution characteristics such as viscosity and surface tension [19]. The atomization pressure, often understood as only a droplet size influencing factor, was proven to have a more complex effect since it also influences the droplet velocity and fluid-bed temperature [24].