A new tablet brittleness index.

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Chemical Engineering

Background:

• Tablet brittleness is a critical factor in powder compaction success and failure.
• Existing methods for quantifying tablet brittleness lack sensitivity or require additional experimental procedures.

Purpose of the Study:

• To identify and validate a suitable index for quantifying pharmaceutical tablet brittleness.
• To establish a new strain-based tablet brittleness index (TBI) for formulation development.

Main Methods:

• Theoretical considerations and statistical analysis of friability data.
• Systematic evaluation of the proposed TBI across various materials, compositions, and compaction parameters.
• Construction of a probability map relating tablet tensile strength, TBI, and friability.

Main Results:

• The reciprocal of diametrical elastic strain at fracture was identified as the most suitable TBI.
• The TBI demonstrated sensitivity to changes in tablet composition (e.g., brittle vs. plastic excipients) and compaction parameters.
• Tablet brittleness was shown to increase with increasing tablet porosity.
• A TBI value of 150 is recommended as the upper limit for pharmaceutical tablets, validated by marketed products.

Conclusions:

• The proposed strain-based TBI offers a reliable and sensitive method for quantifying tablet brittleness.
• This TBI can be calculated from routine diametrical breaking test data, facilitating its adoption in pharmaceutical development.
• The TBI aids in guiding tablet formulation to achieve desired mechanical properties and minimize friability.