Spray freeze drying is a technique wherein an atomized liquid spray is sprayed into a cryogenic medium, and the spray droplets are quickly frozen. Once frozen, these frozen droplets are lyophilized (freeze-dried) to remove the frozen solvent and leave particles behind. This technique can be used as an alternative to conventional spray drying for thermo-sensitive compounds that have particular issues with the heated chamber and/or gas(ses) used in conventional spray drying, but are retained or reacted as desired with the combination of flash freezing and lyophilization. Such a technique may be of particular interest in the pharmaceutical and food industries, as well as for the production of ceramic powders, and perhaps other fields where conventional spray drying or spray pyrolysis may be typically used. This technique may be used to produce microspheres or other microparticles of various morphologies and compositions.
Sonaer nozzles can be used to atomize solutions, suspensions, or slurries into droplets to be flash frozen and later lyophilized. Additionally, Sonaer nozzles and spray shapers such as the pin-point spray shaper or dual microfeed tube (DMF) for spray shaping may be used to carry the droplets to the cryogenic bath, if not also incorporated into the final spray freeze-dried product or utilized to potentially dry the sprayed droplets partially in-flight with a goal of creating smaller final particles. Also, Sonaer may incorporate these technologies and devices into batch-producing spray-freeze drier systems, which incorporate the nozzle(s) and spray shaper(s) of choice with a manifold lyophilizer and automated or at least programmable triggering between spraying and freezing, and freeze-drying and excess gas exhausting.
