Microparticles with homogeneous properties are crucial for pharmaceutical applications where the prior knowledge of exact drug loading and release behaviour is essential to achieve targeted therapeutic goals. Various methods such as membrane microemulsion or templating to assemble uniform particles often involve multiple steps, including post-processing for purification and recovery, with additional chemical reactivity is often required to form solid particles, rendering less flexibility in the procedure. Spray drying is a common method to produce pharmaceutical particles, although control over the particle properties poses a challenge. Here we used a specially designed dryer utilising a micro-fluidic-aerosol-nozzle to atomize monodisperse droplets from a range of precursors, to generate uniform microparticles for controlled release applications. The versatility of the device enabled microparticles with easily tunable drug release kinetics to be assembled by adjusting the drying conditions or the composition of the precursors, including the use of dopants or different solvents. Significant adjustment of the release profiles could be realized by manipulating the microstructure of the microparticles. Due to the homogeneity of the particles, a direct correlation between the microstructural properties and release mechanisms could be obtained, the knowledge of which is crucial for the design of spray-dried polymeric-based pharmaceutical particles.