Redevelopment of Freeze-Drying Processes for Legacy Pharmaceutical Products: A Rational Approach Combining Physical Chemistry and Process Modeling
EducationalLYOPHILIZATION 4.0: SMARTER / FASTER / GREENER
2026-05-27 | 01:20 PM - 01:35 PM | TPD Room
Abstract
This study presents the systematic redevelopment of freeze-drying cycles for two legacy pharmaceutical products (designated "A" and "B") originally developed in the 1960s. The products required transfer from subcontract manufacturing to internal production facilities, presenting significant challenges due to limited historical process data and pharmaceutical elegance issues inherent to the original formulations.
The redevelopment approach integrated fundamental physical chemistry characterization (glass transition temperature Tg', eutectic temperature) with iterative process modeling and experimental validation. Key process parameters including vaporization coefficient (Kv) and product resistance (Rp(h)) were determined through systematic experimentation, enabling physics-based understanding of sublimation dynamics and predictive process capability.
The target industrial freeze-dryer specifications (30 m² capacity: 72,000 × 7 mL or 42,000 × 15 mL vials; maximum sublimation rate ~10.5 kg/h mean flow at 150 µbar) imposed critical hydrodynamic constraints that were successfully addressed through the modeling approach. Process monitoring utilizing capacitive and Pirani pressure probes enabled reliable detection of primary drying endpoints.
This rational methodology successfully resolved both pharmaceutical elegance and industrial productivity challenges, yielding optimized, robust freeze-drying cycles with complete scientific justification for validation batches. The approach demonstrates the value of combining fundamental physical chemistry principles with process engineering to modernize legacy pharmaceutical manufacturing processes while ensuring product compliance and maximizing operational efficiency.
