Spray-Drying of Enzymes on the Bench-Top Scale with lengthened Chamber Retention Time
The idea for this project was to change the design of a lab-scale spray dryer. The new device from ProCept provides factory-set a larger drying chamber length compared to other bench-top units. The residence time of the droplets in the hot air is therefore elongated and larger particles should be obtained. Furthermore, a laminar provided flow rate of the inlet air reduces the affinity of the droplets to the inside chamber wall. The drying chamber can also be extended to increase the droplet/particle residence time. In the current work a monodisperse atomizer in the ProCept device is examined with the possibility to adjust the size of the generated droplets to desired values. Both two-fluid and ultrasonic atomizers are also characterised. In a second part of the project the validity of the Arrhenius equation for a spray-drying process is examined. The energy of activation is calculated and used as a measure of the stabilizing effect of various excipients.