(402e) Powder Lubrication in a Continuous Mixing Process

In traditional batch processes, a lubricant, such as magnesium stearate, is incorporated into the blend during the final processing step before tablet compression.  Recent models, from Kushner and Moore, have proposed a process scaling parameter for a number of different formulations to facilitate scale up of these batch-based processes.  In the current work, a series of powder lubrication experimental trials have been completed using an in-line powder mixer.  The influence of mass throughput rate, hold up mass of powder in the mixer, and the impeller rotational speed is studied.  A new process scaling term, based on the tip speed of the impeller and the mean residence time is proposed for this continuous mixing process and compared to the model proposed by Kushner and Moore for batch processes.     Additionally, two new sensors (NIR and torque) are evaluated as part of these experimental trials and introduced as potential on-line PAT techniques for monitoring powder lubrication in a continuous mixer.