Up to 90% of the active pharmaceutical substances under development are poorly water soluble, usually resulting in low oral bioavailability (BCS class II and class IV). To overcome this issue, different engineering and formulation approaches have been developed. Three notable examples are i) size reduction techniques, ii) cocrystallization and iii) production of amorphous solid dispersions. The current work describes a continuous process based on Micro-Reaction-Technology to produce crystalline drug particles, cocrystals or amorphous solid dispersions in the particulate form in the micro- and/or nano-range. The homogeneous and rapid mixing between two fluids that is achieved through this technology enables the fine control of the particle characteristics (e.g. particle size, morphology, polymorphic form). Three case-studies of the production of nano-crystal, cocrystals and amorphous solid dispersion will be detailed in this work.