Cryopelletization is a technique in which droplets of a liquid formulation are transformed into solid spherical particles or pellets through the use of liquid nitrogen as the fixing medium.
This technology, originally developed for the lyophilization of viscous bacterial suspensions, is capable of producing drug-loaded pellets in liquid nitrogen at -1600C. The process allows for immediate and uniform freezing of the material being processed due to the rapid heat transfer that takes place between the droplets and the liquid nitrogen.
The quantity of liquid nitrogen needed for the production of a specific amount is contingent upon the solids content and temperature of the solution or suspension being treated.
The equipment comprises a container fitted with perforated plates, a reservoir, a conveyor belt with transport baffles, and a storage container. The perforated plates create droplets that fall and freeze instantly upon contact with the liquid nitrogen, while the frozen pellets are subsequently moved out of the nitrogen bath into a storage container at -600C prior to the drying process.