Characterization and evaluation of isomalt performance in direct compression

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Isomalt, a sugar substitute, possesses valuable physicochemical properties for pharmaceutical applications.
• Its potential for direct compression tableting necessitates thorough evaluation of different grades.

Purpose of the Study:

• To assess the suitability of four isomalt grades for direct compression in pharmaceutical formulations.
• To investigate the impact of lubricants, glidants, and drug dilution on tablet properties and performance.

Main Methods:

• Evaluation of physical characteristics of four isomalt grades.
• Tabletting studies using a single-punch machine with varying lubricant and glidant concentrations.
• Heckel analysis to determine compression behavior and elastic recovery.
• Dilution studies with paracetamol to assess drug-excipient compatibility and tablet properties.
• Dissolution testing and stability assessment under varying humidity conditions.

Main Results:

• Palatinit C and F grades demonstrated potential for direct compression.
• Optimal tabletting performance for Palatinit C was achieved with 1% lubricant and 0.5% Aerosil 200 to improve flow.
• Isomalt exhibited plastic deformation with elastic recovery during compression.
• Acceptable tablets were produced with up to 30% paracetamol, though tensile strength decreased and disintegration/friability increased.
• Drug dissolution rate decreased with increased compression force and drug concentration, but improved with a disintegrant.
• Tablets showed good physical stability after six months due to isomalt's low hygroscopicity.

Conclusions:

• Isomalt, specifically Palatinit C, is a viable excipient for direct compression tableting when appropriately formulated.
• Formulation optimization with lubricants and glidants is crucial for achieving desired tablet properties.
• The low hygroscopicity of isomalt contributes to the long-term stability of the formulated tablets.