Product description
Single-use freeze-thaw bags are disposable bioprocess containers designed for controlled freezing, frozen storage, thawing and low-temperature transport of pharmaceutical and biopharmaceutical process fluids.
The bags use a flexible multilayer film specifically developed for low-temperature applications. The product-contact layer is based on EVA, providing flexibility and resistance to the mechanical stresses associated with freezing and thawing.
Standard configurations are available from small-volume 30 mL bags through 12 L freeze-thaw systems. Larger configurations incorporate a protective shell that supports the bag, tubing and connections during freezing, handling, storage and transport.
Technical overview
Freezing a liquid inside a flexible bioprocess bag creates mechanical stress as the liquid expands and the film becomes less flexible at low temperature. A dedicated freeze-thaw system is therefore designed around both the flexible container and the protection required during frozen handling.
Small-volume configurations are available as standalone bags, while larger 2 L, 6 L and 12 L systems integrate the bag with a protective structure.
Tubing and process connections can be configured for filling, draining, sterile connection and transfer before or after the freeze-thaw process.
Operating principle
Process fluid is transferred into the flexible bag through the configured inlet connection. The bag is then positioned correctly within its protective system before freezing.
During freezing, the bag and fluid path remain supported to reduce uncontrolled movement and mechanical impact. The protective structure also provides fixed locations for the tubing and connections.
Once frozen, the complete system can be stored or transported under the validated low-temperature conditions of the process.
During thawing, the frozen product is allowed to return to the required processing temperature using the validated thawing procedure. Product can subsequently be transferred through the existing tubing and connections without transferring the frozen material to another container.
Material options
Standard freeze-thaw bags use a 360 µm multilayer co-extruded freeze-resistant film manufactured using a blown-film process.
The construction uses an EVA product-contact layer, selected for flexibility and low-temperature performance.
Tubing and fluid-path options can include:
- EVA tubing for suitable small-volume configurations
- Weldable TPE tubing
- Silicone tubing for suitable custom configurations
- Aseptic connection technology
- Quick-connect process connections
- Luer connections for small-volume systems
Final material selection should be confirmed against the process fluid, freezing temperature, thawing conditions and required connection technology.
Available micron ratings
Not applicable. Freeze-thaw bags are storage and fluid-handling containers rather than filtration media and therefore do not have a micron or pore-size rating.
Where filtration is required before filling or after thawing, a suitable filtration assembly can be connected or incorporated into the overall single-use fluid path.
Design and construction
Available volumes
Published freeze-thaw bag configurations include:
- 30 mL
- 60 mL
- 100 mL
- 2 L
- 6 L
- 12 L
The currently standard selectable configurations include 30 mL, 100 mL, 2 L, 6 L and 12 L. Other volumes should be confirmed during configuration.
Small-volume freeze-thaw bags
30 mL and 100 mL configurations are available without an external protective shell and are intended for small-volume frozen storage applications.
Suitable configurations can use EVA tubing with Luer connections for compact filling and transfer fluid paths.
Integrated protected freeze-thaw systems
The 2 L, 6 L and 12 L configurations combine the flexible freeze-thaw bag with an external protective structure.
The protection system helps:
- Support the flexible bag during freezing
- Protect the frozen bag during handling
- Fix tubing and connections in defined positions
- Reduce impact on the frozen fluid container
- Support stacking during storage
Up to four suitable systems can be stacked to improve utilisation of frozen storage space.
Dimensions
| Volume | Configuration | Approximate dimensions |
|---|---|---|
| 2 L | Bag + protective shell | 430 × 360 × 122 mm |
| 6 L | Bag + protective shell | 605 × 480 × 128 mm |
| 12 L | Bag + protective shell | 690 × 530 × 130 mm |
Tubing and connection options
Standard configurations include several tubing and process-connection concepts.
- EVA tubing with 1/4" female Luer Lock and matching closure for suitable small-volume systems
- 3/8" ID × 5/8" OD TPE tubing with quick-connect interfaces
- 3/8" ID × 5/8" OD TPE tubing with aseptic connectors
- Custom silicone or TPE fluid paths where required
Exact tubing length, number of lines and connection technology can be adapted to the filling, storage and post-thaw transfer process.
Operating temperature
The freeze-thaw system is designed for low-temperature applications down to approximately -80°C.
For normal freeze-thaw process applications, a working range of approximately -80°C to 40°C should be used as the initial design range. Any requirement above this range should be technically confirmed for the complete bag, tubing and connection configuration.
Frozen transport and handling
Suitable freeze-thaw configurations are designed not only for freezing and storage but also for low-temperature transport.
Performance testing for the system includes:
- -80°C freezing testing
- Transport testing
- Stacking testing
- Drop testing under frozen conditions
- Simulated manual-handling drop testing
- ISTA-3A transport testing
These tests support evaluation of the complete protection concept during frozen handling and distribution.
Integrity testing
Standard freeze-thaw bags are subject to 100% leak testing prior to release.
Integrity requirements for a custom assembly should be confirmed for the complete bag, tubing and connection configuration.
Sterilisation and supply condition
The published standard freeze-thaw bag configurations are supplied non-sterile.
Custom configurations with aseptic connection technology are available. Where a sterile or irradiated assembly is required, compatibility and sterilisation conditions should be confirmed for the complete assembly before specification.
Production and documentation
Standard freeze-thaw bags are manufactured in a controlled ISO Class 4.8 cleanroom environment and are produced for use in cGMP manufacturing processes.
Available quality and conformity documentation can include:
- USP <788> Particulate Matter
- USP <87> Cytotoxicity
- USP <88> Biological Reactivity
- USP <85> bacterial endotoxin information
- FDA 21 CFR 177–182 material conformity information
- Animal-derived component-free material statements
- TSE / BSE documentation
- Certificate of Analysis or Certificate of Quality
- Integrity-test documentation
- Freeze, transport and handling validation documentation where applicable
Exact documentation should be confirmed for the final bag and fluid-path configuration.
Typical applications
- Frozen drug substance storage
- Biopharmaceutical intermediate storage
- Bulk biological product storage
- Monoclonal antibody storage
- Vaccine intermediate storage
- Recombinant protein storage
- Blood-product processing
- Cell and gene therapy processing
- Low-temperature process-fluid storage
- Freeze-thaw process development
- Frozen product transport
- Cold-chain bioprocess logistics
Key benefits
- Designed for low-temperature processing: dedicated multilayer film supports freezing applications down to approximately -80°C.
- EVA product-contact layer: the freeze-resistant film construction provides flexibility for repeated freezing and thawing conditions.
- Protected large-volume configurations: 2 L, 6 L and 12 L systems combine the bag and protective structure.
- Tubing protection: tubing and connections can be fixed within the protective structure to reduce movement during frozen handling.
- Stackable design: suitable protected systems can be stacked to improve frozen-storage utilisation.
- Frozen transport capability: system performance has been evaluated through transport, stacking, freezing and drop testing.
- Multiple connection options: Luer, quick-connect and aseptic connection configurations are available.
- Custom fluid paths: tubing material, dimensions and process connections can be configured around filling and post-thaw transfer requirements.
Configuration and quotation
Freeze-thaw bag selection should be based on working volume, freezing temperature, storage method and handling requirements rather than nominal bag volume alone.
For technical configuration and quotation, provide the following information where available:
- Required working volume
- Process fluid
- Minimum freezing temperature
- Maximum thawing temperature
- Number of expected freeze-thaw cycles
- Static storage or frozen transport requirement
- Required tubing material
- Tubing ID and OD
- Required tubing lengths
- Inlet and outlet connection types
- Aseptic connection requirement
- Required protective shell or handling system
- Freezer type and available dimensions
- Storage and stacking requirements
- Sterilisation requirement
- Required conformity and validation documentation
- Prototype or qualification quantity
- Estimated annual demand
- Existing freeze-thaw specification or process drawing where available
If the final system has not yet been defined, working volume, minimum temperature, process fluid and required process connections provide a suitable starting point for technical selection.