Microfluidic spray drying device for process-oriented product development with low sample consumption

The production of functional particle systems is becoming increasingly important in many industries. In the early development of such products, there is often not a sufficient amount of educts available or the educts are expensive and/or toxic. For this purpose, lab-scale processes are used which often differ from the later production processes. Unfortunately, the processes have a direct impact on the product properties. That makes a subsequent transfer from the unconventional lab methods to the actual fabrication process necessary, which is often associated with problems. To avoid complex additional efforts in the development of new functional particle systems and, thus, shorten the time to market, a modular microfluidic spray dryer was developed. With our new microfluidic spray dryer made from glass, it is possible to produce droplet sizes and, thus, particle sizes similar to those of conventional spray dryers in the lab or even in the production but using only smallest quantities of starting materials (product volume flow rates down to 0.03 ml/min). During the development of the micro spray dryer, process and formulation parameters as well as various microchannel geometries were investigated to determine their influence on droplet formation and, thus, on product formation. The developed micro spray dryer can be operated with various formulations and material compositions, as the micro system is made of chemically inert material, is easy to clean, pressure-resistant and can be used in a wide range of pH values.