Freeze Mapping - Savillex Fluoropolymer Bottles

Significance of the Topic

Freezing bulk drug substances at or below –80 °C is a cornerstone of bioprocess preservation and logistics. Containers must withstand rapid temperature shifts without deformation or loss of function. Fluoropolymer bottles—made from PFA and ETFE—offer high durability, chemical inertness, and maintain their shape during flash freezing and thawing. Their compatibility with standard laboratory freezers, water baths, shelving, and shipping systems makes them especially valuable for streamlined workflows in pharmaceutical and biotech environments.

Study Objectives and Overview

This study aimed to quantify the time required to flash freeze and subsequently thaw water-filled Savillex fluoropolymer bottles of varying capacities. By mapping freeze-to–80 °C and thaw-to–20 °C profiles across six bottle volumes, the work provides practical guidelines for equipment selection and process planning in laboratory and production settings.

Methodology and Instrumentation

The investigation employed six bottle sizes (50, 100, 250, 500, 1 000, and 2 000 mL) with three replicates each. Key steps included:

• Filling bottles to nominal capacity with room-temperature water.
• Embedding 1/16″ Type K thermocouples at a fixed depth to monitor internal temperature.
• Freezing in a standard upright –85 °C laboratory freezer for 24 hours.
• Thawing immediately in a 37 °C recirculating water bath until the internal temperature reached 20 °C.

The temperature data were logged via a four-channel datalogger throughout both processes.

Results and Discussion

Freeze and thaw times scaled predictably with volume:

• 50 mL: 144 min to –80 °C, 29 min to 20 °C
• 100 mL: 171 min, 32 min
• 250 mL: 266 min, 59 min
• 500 mL: 378 min, 86 min
• 1 000 mL: 539 min, 142 min
• 2 000 mL: 766 min, 191 min

Temperature curves were smooth for all sizes, with minor fluctuations above 0 °C observed in larger volumes during thaw due to melting ice mixing with warmer water. Overall variability between replicates was minimal, indicating a robust and reproducible freeze–thaw profile.

Practical Benefits and Applications

Fluoropolymer bottles demonstrate:

• Structural integrity and consistent thermal performance under flash freezing.
• Ease of use in standard freezers and water baths without specialized racks or supports.
• Scalability across a wide range of volumes for research, QA/QC, and small‐batch manufacturing.

These attributes facilitate faster process development, reduce equipment investment, and improve workflow efficiency in biopharmaceutical and analytical laboratories.

Used Instrumentation

• Purillex PFA and ETFE fluoropolymer bottles (50–2 000 mL)
• Upright –85 °C laboratory freezer
• 18 L recirculating water bath at 37 °C
• 4-channel datalogger with Type K thermocouples

Future Trends and Opportunities

Potential developments include:

• Extending freeze–thaw mapping to various product formulations (buffers, media, high–viscosity fluids).
• Optimizing bottle geometry and orientation for accelerated heat transfer.
• Implementing real‐time telemetry for remote monitoring and process control.
• Evaluating next‐generation fluoropolymers and composite materials for enhanced thermal performance.
• Scaling workflows for pilot and production‐scale freezing systems.

Conclusion

This study confirms that Savillex fluoropolymer bottles provide a consistent, reproducible solution for flash freezing and thawing of aqueous solutions in standard laboratory equipment. The measured time profiles serve as reliable guidelines for process design, although actual performance may vary with fluid properties, equipment capacity, and operational conditions. Additional application‐specific testing is recommended to fine‐tune freeze–thaw protocols.

References

Savillex. Freeze Mapping – Savillex Fluoropolymer Bottles. Technical Note TN028, January 04 2021.