The DELOS process, based on the use of compressed fluids, is an efficient crystallization/precipitation method for the one step production of crystalline micron-and nanosized particles of active pharmaceutical ingredients with high polymorphic purities and minimum residual solvent residues. The particle size of the processed powders can be easily modulated by controlling operational parameters. This new process can provide real advantages over conventional crystallization processes, such as (1) high purity products, (2) control of crystal polymorphism, (3) in-process elimination of residual solvent/reduction of residual solvent levels, (4) processing of thermolabile and waxy compounds, (5) single-step in single-area process, (6) easy and reproducible scale-up (7) environmentally friendly technology (8) technically and economically viable process at industrial scale.

In contrast to supercritical fluids antisolvent techniques, the DELOS process takes advantage of the cosolvent behavior that compressed CO2 presents over solutions of active drugs and polymers in certain organic solvents. DELOS has been used for the successful micronization (1 to 10 mm) and nanosizing (100 to 1000 nm) of APIs and biodegradable polymers. Although less explored than antisolvent techniques, DELOS offers remarkable advantages such as less consumption of CO2, mild conditions and easier scalability because there is no need of nozzles and complex agitation systems.