Interparticle van der Waals force in powder flowability and compactibility.

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Chemical Engineering

Background:

• Particle flowability and compactibility are crucial for pharmaceutical tabletting.
• These properties are influenced by particle characteristics and operational conditions, but lack fundamental quantitative understanding.
• Existing measurement methods provide comparative indices but not deep insights into underlying forces.

Purpose of the Study:

• To establish quantitative connections between interparticle van der Waals forces and powder flowability.
• To elucidate the relationship between interparticle forces and powder compactibility.
• To explore the inter-relations between flowability and compactibility through fundamental particle properties.

Main Methods:

• Theoretical development linking interparticle van der Waals forces to powder mechanical behavior.
• Experimental validation using paracetamol and associated excipients, known for poor flow and compaction.
• Analysis of geometrical, physical, chemical, and mechanical particle properties.

Main Results:

• Demonstrated a quantitative link between van der Waals forces and both flowability and compactibility.
• Provided insights into the inter-relations between these two critical tabletting parameters.
• Validated the theoretical framework using challenging pharmaceutical powders.

Conclusions:

• Interparticle van der Waals forces are a key determinant of pharmaceutical powder flowability and compactibility.
• A fundamental understanding of these forces can improve tablet formulation and process design.
• This work offers a pathway to quantitatively predict and control tabletting behavior.