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Bulk Dynamic Spray Freeze-Drying Part 1: Modeling of Droplet Cooling and Phase Change.
Israel B Sebastião1, Bakul Bhatnagar2, Serguei Tchessalov2
1Purdue University, School of Aeronautics and Astronautics, West Lafayette, Indiana 47907; Pfizer Inc., BioTherapeutics Pharmaceutical Sciences, Andover, Massachusetts 01810.
Journal of Pharmaceutical Sciences
|January 25, 2019
Summary
Spray freeze-drying (SFD) offers faster bulk lyophilization of drugs. This study presents a validated spray-freezing model to optimize particle formation and improve process efficiency for industrial scale-up.
Area of Science:
- Pharmaceutical Technology
- Chemical Engineering
- Materials Science
Background:
- Spray freeze-drying (SFD) enables higher production rates for lyophilized drugs compared to conventional methods.
- The process involves dispersing solutions into a cold gas to form frozen microparticles, followed by sublimation drying.
- Product characteristics in SFD are primarily governed by spray-freezing dynamics, necessitating precise control.
Purpose of the Study:
- To develop and validate a single droplet spray-freezing model.
- To provide a predictive tool for optimizing SFD processes.
- To support the scale-up of SFD technology from laboratory to commercial applications.
Main Methods:
- Development of an engineering-level spray-freezing model for single droplets.
- Validation of the model using previously published simulation data.
- Experimental validation of predicted droplet temperature evolutions.
Main Results:
- The developed model accurately predicts droplet temperature during spray freezing.
- Model predictions show agreement with experimental data within a ±10% error margin.
- The model provides a robust framework for understanding and controlling SFD dynamics.
Conclusions:
- The validated spray-freezing model is a valuable tool for SFD process development.
- This modeling approach can aid in optimizing particle formation and drying efficiency.
- The framework supports the scale-up of SFD technology for bulk lyophilization manufacturing.
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