Relationships among material plasticity, tablet brittleness, and tensile strength

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Chemical Engineering

Background:

• Tablet mechanical strength is crucial for pharmaceutical formulations.
• It is influenced by intrinsic material properties and compaction process parameters.
• Understanding these relationships is key for robust tablet design.

Purpose of the Study:

• To investigate the relationships between tablet tensile strength, tablet brittleness index, and powder plasticity (in-die mean yield pressure).
• To establish predictive models for tablet mechanical properties based on powder behavior.
• To offer an efficient method for early-stage tablet development guidance.

Main Methods:

• Selected seven common excipients and twelve binary mixtures representing diverse mechanical behaviors.
• Characterized tablet tensile strength and brittleness index at varying porosities.
• Quantified powder plasticity using in-die mean yield pressure from compression data.

Main Results:

• Tablet strength and brittleness decreased exponentially with increasing porosity for all materials.
• A power-law correlation was found between in-die mean yield pressure and tablet brittleness index at fixed porosity.
• This correlation allows direct prediction of tablet brittleness from yield pressure.

Conclusions:

• In-die mean yield pressure is an effective predictor of tablet brittleness.
• This method provides an efficient way to estimate tablet mechanical properties early in development.
• The findings guide the design of robust tablets with desired mechanical strength.