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Granule breakage during drying processes.
Florentine J S Nieuwmeyer1, Kees van der Voort Maarschalk, Herman Vromans
1Department of Pharmaceutics, NV Organon, P.O. Box 20, 5340 BH Oss, The Netherlands.
International Journal of Pharmaceutics
|September 29, 2006
Summary
Granule breakage during drying is linked to water content, following growth, plateau, and breakage phases. Understanding these phases and granule stress is key to controlling size reduction in pharmaceutical manufacturing.
Area of Science:
- Pharmaceutical Technology
- Chemical Engineering
- Materials Science
Background:
- Wet granule drying often leads to uncontrolled size reduction, impacting product quality.
- Current FDA Process Analytical Technology (PAT) guidance emphasizes process control and understanding.
- Investigating granule breakage phenomena during drying is crucial for effective process control.
Purpose of the Study:
- To determine and understand the mechanisms of granule breakage during drying processes.
- To identify critical process parameters influencing granule size reduction.
- To provide insights for controlling granule size during drying.
Main Methods:
- High shear granulated lactose granules were prepared using water as a binding liquid.
- Granules were dried for variable periods and subsequently subjected to agitation.
- Granule size changes were characterized as a function of water content and applied stress.
Main Results:
- Granule size change during drying follows a three-phase system: growth, plateau, and breakage.
- Granule yield stress is dependent on velocity and water content.
- In the plateau phase, granule strength aligns with Rumpf's dynamic granule strength; below minimum water content, solid bridges dominate.
Conclusions:
- Granule breakage is critically dependent on water content and applied stress during drying.
- The identified three-phase system provides a framework for understanding and controlling granule size.
- Controlling stress and water content during drying is essential to mitigate unwanted size reduction.
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