In a study that is described in detail in our report available here DFF sensor was installed inside the bowl of a vibratory dryer. The harsh conditions (acceleration of up to 30g, low pressure of 10-20 Torr and temperature below -6 C) did not affect the probe operation and did not damage the sensor.
FPM signature of drying cycles provided rich amount of data seemingly responding to most changes happening in the process. Specifically:
DFF sensor reliably differentiated dry placebo from dry active formulations
With high sensitivity resolved change in the vibration frequency
Demonstrated ability to characterize both motion of fine powder and individual impacts of large granules and agglomerates
Both for placebo and active formulations the FPM and WFPM readings were indicative of the key process points such as formation and braking the granules, formation and breaking the cake on the bottom of the dryer
FPM signatures were consistent with expected processing end points
By monitoring characteristic features in the FPM and PCF signatures, LIR can be used as a tool for scaling up the process.