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Updated: May 28, 2026

05:45
Process Development for the Spray-Drying of Probiotic Bacteria and Evaluation of the Product Quality
Published on: April 7, 2023
Design space approach in the optimization of the spray-drying process
Pierre Lebrun1, Fabrice Krier, Jérôme Mantanus
1Laboratory of Analytical Chemistry, CIRM, University of Liège, Liège, Belgium. plebrun@ulg.ac.be
Summary
This study demonstrates Bayesian statistics for identifying the spray-drying Design Space (DS), ensuring product quality. The validated optimal conditions confirm predictable, high-quality powder production.
Area of Science:
- Pharmaceutical Technology
- Process Chemistry
- Statistical Modeling
Background:
- Quality by Design (QbD) principles are crucial for pharmaceutical manufacturing.
- Identifying the Design Space (DS) ensures consistent product quality.
- ICH Q8 guidelines define DS as a multidimensional parameter combination assuring quality.
Purpose of the Study:
- To apply Bayesian statistical methodology for defining the spray-drying process Design Space (DS).
- To establish a predictive, risk-based approach for process control and quality assurance.
- To validate the identified optimal conditions within the DS.
Main Methods:
- Utilized Bayesian statistical methodology to model process variables and critical quality attributes.
- Implemented a predictive risk-based approach to manage uncertainties and correlations.
- Defined process specifications based on safety, efficiency, and economic factors.
- Validated the optimized process parameters: inlet temperature, feed rate, and spray flow rate.
Main Results:
- Successfully identified the Design Space (DS) for the spray-drying process.
- Quantified process guarantees and risks, ensuring operation within specifications.
- Validated optimal conditions demonstrated predictable performance and built-in quality.
- Achieved desired critical quality attributes including yield, moisture content, and inhalable fraction.
Conclusions:
- Bayesian statistical methodology is applicable for defining the spray-drying DS.
- The QbD approach, utilizing Bayesian statistics, ensures product quality and process control.
- Validated optimal conditions confirm the robustness and reliability of the spray-drying process.

