Mechanistic models with experimental comparison for microwave-assisted lyophilization in a vial

Area of Science:

• Pharmaceutical manufacturing
• Chemical engineering
• Process modeling

Background:

• Microwave heating accelerates pharmaceutical lyophilization but lacks robust process models.
• Existing models often oversimplify heat transfer and structural complexities.
• Accurate modeling is essential for process optimization and preventing product damage.

Purpose of the Study:

• To develop a more accurate 2D level set simulation for microwave-assisted lyophilization.
• To refine assumptions in traditional lumped capacitance (LC) models.
• To provide open-source code for enhanced process modeling.

Main Methods:

• Developed a 2D level set simulation integrating experimental data and porous structures.
• Refined a 0D lumped capacitance (LC) model by reducing empirical parameters.
• Validated the LC model against experiments in microwave-assisted lyophilization and vacuum drying.

Main Results:

• The 2D level set model offers improved accuracy over traditional LC models.
• One empirical parameter was removed, and two were estimated using electromagnetic simulations.
• Experiments confirmed the importance of vial wall heating and heat conduction in microwave drying.

Conclusions:

• The refined LC model provides a more accurate representation of microwave-assisted lyophilization.
• Accurate modeling must consider vial wall effects and heat transfer dynamics.
• Open-source implementation facilitates wider adoption and further research in pharmaceutical drying processes.