The effect of compression on the capillary microstructure of tablets

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Physical Chemistry

Background:

• Understanding powder behavior under compression is crucial for pharmaceutical formulation.
• Capillary characteristics influence drug dissolution and release kinetics.
• Compaction pressure is a key parameter affecting solid dosage form properties.

Purpose of the Study:

• To investigate the impact of compaction pressure on the capillary penetration properties of crystalline drug and pure polymer compacts.
• To analyze the relationship between compaction pressure and the kinetics of capillary penetration.
• To explore the structural homogeneity of compacts as a function of applied pressure.

Main Methods:

• Capillary penetration measurements were employed to assess compacts.
• Porosimetry techniques were utilized to characterize pore structure.
• Analysis of the volume-time relationship (V = Kmtm) was performed.

Main Results:

• Both the constant (K) and exponent (m) in the penetration volume-time relationship were pressure-dependent.
• Increasing compaction pressure led to a decrease in the exponent 'm'.
• Polymer compacts exhibited structural heterogeneity at lower pressures, becoming homogeneous at higher pressures.

Conclusions:

• Capillary penetration measurements provide valuable insights into pharmaceutical powder behavior during compression.
• The observed variations in capillary penetration kinetics are linked to particle deformation.
• Compaction pressure critically influences the structural integrity and capillary properties of pharmaceutical compacts.