A modified Kushner-Moore approach to characterising small-scale blender performance impact on tablet compaction

Area of Science:

• Pharmaceutical Technology
• Chemical Engineering
• Materials Science

Background:

• Continuous Direct Compaction (CDC) offers reduced material, time, and energy in solid dosage form production.
• Understanding powder blender performance is crucial for CDC, yet existing research focuses on low-intensity batch operations.
• Traditional batch blenders operate at low Froude numbers (Fr < 0.4), limiting their mixing intensity and applicability to CDC.

Purpose of the Study:

• To investigate the performance of a novel mini-blender with a different operational mode (static vessel, rotating blades).
• To compare the mini-blender's lubrication dynamics and impact on tablet quality attributes with conventional blenders.
• To evaluate the influence of mixing intensity (Froude number) and operational parameters on powder blending for CDC.

Main Methods:

• Utilized a mini-blender with a static vessel and rotating shaft with blades.
• Varied mixing intensity and regimes within the mini-blender's wider operating range (including Fr > 1).
• Analyzed tablet compaction data and modified existing lubrication models by incorporating the Froude number.

Main Results:

• Tablet compaction data from the mini-blender followed a common trajectory across different mixing intensities.
• Modified model equations accurately predicted outcomes at high Froude numbers (Fr > 1).
• Mixing intensity (Froude number) and revolutions were critical for lubrication dynamics, while fill level was less important in the mini-blender.

Conclusions:

• The mini-blender's design allows for higher mixing intensities, crucial for efficient lubrication in CDC.
• Mixing intensity, represented by the Froude number, is a key parameter for predicting lubrication dynamics in this novel blender system.
• The approach demonstrates validity across different formulations, highlighting its potential for optimizing CDC processes.