POWDER FEEDING SYSTEM
Drug product continuous manufacturing often relies on multiple material feeding devices to feed the unit formula accurately and consistently into the process. An individual feeding device’s target mass flow is a function of the process total mass flow and unit formula. Maintaining the unit formula is critical to ensure product efficacy and patient safety. Therefore, the ability of the current feeding devices determines the process minimum total mass flow value. There are multiple reasons to process smaller batch sizes at low total mass flows during development and commercial manufacturing which drives the need for an individual material feeding device capable of feeding at low mass flows.
The feeding mechanism of the feeder typically involves transporting the material within its chamber and accurately metering it into the required process or a unit operation. The performance of feeding is often strongly dependent on properties of the material being fed such as bulk density, cohesiveness, flowability etc. Therefore, it is desired for the device to accurately feed materials with
• a bulk density of approximately 0.20 g/mL or less and (e.g. freeze-dried materials, aerosol materials) and/or
• a flow function coefficient (FFC, measure of material flowability) of 2.0 or less.
• Example materials – Cab-O-Sil silicon dioxide or lubricants (magnesium stearate or sodium stearyl fumarate)