Bottles vs Freezing Bags: Regulatory & Quality Comparison

Making the switch from bottles to single-use bags can help biopharma companies reduce costs, improve efficiency, and strengthen regulatory documentation around bioprocesses that rely on freeze and thaw applications, especially during scale-up.

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Many biomanufacturing processes rely on freeze and thaw operations to maintain quality and stability of biopharmaceutical products. Using conventional glass or plastic storage bottles such as carboys for freeze and thaw operations introduces the risk of product quality variation, and of bacterial contamination, when drug substance is processed, stored, or transported.

Holding specimens and biologics at sub-zero temperatures is essential for many bioprocesses, but biologics can be sensitive to the adverse effects of cryo-concentration and thawing.¹ Critical quality attributes can be compromised if samples are frozen or thawed too slowly or unevenly.

Regulatory and quality demands around the management of bio-samples during freeze and thaw are adding new pressure that traditional storage and transportation methods may not be able to handle. As new technologies and processes emerge that raise the bar for understanding, monitoring, and controlling critical process parameters for even storage and thawing steps, it may become hard to continue to justify the use of bottle technology from a regulatory standpoint, especially once you start scaling up the process with an eye on commercialization.

From uneven freezing, to meeting packaging requirements for shipping, using bottles for frozen drug substance management has some recognized disadvantages.¹ Some of the limitations of existing systems include scalability, logistics (shipping without breakage or jostling), extensive and time-consuming sterilization processes, container closure integrity, and unpredictable conditions that hinder process controls and add ambiguity to monitoring.

Pressure from Regulatory Agencies

Regulatory authorities place tight restrictions on the variability allowed within a process to maintain stated critical quality attributes. Being able to demonstrate that your biologic substances stayed within your stated parameters during all freeze and thaw operations for each batch, is vital. Some containers, such as bottles, can add unexpected problems to your process from contamination, uneven freeze and thaw patterns, and breakage.

Regulatory agencies require containers used for pharmaceutical manufacturing and shipping to meet strict sterility standards (21 CFR 211):

Drug product containers and closures shall be clean and, where indicated by the nature of the drug, sterilized and processed to remove pyrogenic properties to ensure that they are suitable for their intended use.

Bottle suppliers may offer limited information or certifications about cleanliness, so this puts the burden of proof about bottle sterilization on the user. That means bottles need either autoclaving or irradiating upon arriving at a sterile facility. Then, sterility can only be maintained by using the bottles under a laminar flow or BSC, which adds additional operational time and costs to the process.

The FDA offers similarly restrictive guidance about container closure integrity:
 

The integrity of the container / closure system is critical to assuring that all units of drug products remain sterile through shipment, storage and use. Leaking containers or closures lead to product contamination.

Conventional bottle closures can literally become the weak link in the cold chain.

Limitations of Bottle Technology for Freeze and Thaw

Generally speaking, the robustness of bottles at low temperatures is poor. Cracking and breakage are common. This can cause lost batches or samples, or if undetected, lead to an unexplained source of contamination in the bioprocess.

With bottles, freezing behavior may vary from bottle to bottle depending on dimensions and position within the freezer. With compounds sensitive to degradation or denaturation by cryo-concentration, this can lead to variations in product quality or changes in activity across a batch.

Some studies have shown that a pH shift, protein denaturation or formation of aggregates can occur during uneven freezing and thawing cycles. [¹] With product close to the walls of the bottle being least affected, and the highest concentrations of aggregates and denatured protein typically occurring in the center and bottom of the container.  [²]. This type of cryo-concentration can wreak havoc with process characterization and validation, and hinder quality by design (QbD) efforts.

Process scale-up creates additional challenges. Not only does an increasing bottle / container size decrease the freezing and thawing rates, potentially worsening the cryo-concentration effect, but the aspect ratio of vessels will typically change as well making the freezing and thawing performance even more challenging to predict. These factors combined mean that scale up in bottles makes maintaining critical process parameters, and thus critical quality attributes, exceedingly difficult.

Aseptic processing requirements for bottles add another layer of complexity. Operator aseptic technique training is more critical due to the need to perform all operations under LAF to maintain sterility. This increases risk and wastes operator time.

The robustness of bottles during the complete life cycle may be unvalidated, and cracks or leaks can compromise sterile operations. Bottles closures may lose integrity at low temperatures, which creates a higher risk for contamination. Gaining validation about bottle performance under low temperature conditions, or frozen robustness data, may be non-exist from many bottle manufacturers.

With bottles, the entire validation burden is on you, including shipping validation. There is an increasing interest from the regulatory bodies in the influence of leachables from primary packaging and their characterization, as well as their influence on product quality. It is rare for this information to be available from bottle suppliers. If you’re shipping in an insulated container with dry ice, you’ll need to validate the solution, and demonstrate to the regulatory authorities that the temperature during shipment remains below the necessary temperature to maintain product quality, and that the container integrity was not compromised during shipping.

Improve Robustness Across all Steps of the Product Lifecycle

The Celsius^® portfolio represents 15+ years of experience in frozen storage and shipping.  The Celsius^® products help you improve robustness across all steps of the product lifecycle. This complete cold chain management system is designed specifically to keep up with regulatory demands and quality assurance during freeze and thaw processes.

From filing to freezing and storage to shipping and thawing, Sartorius Celsius^® products are designed and rigorously tested to ensure safe conditions for biological specimens. The extensive robustness testing comes with large sets of validation data across various temperatures and use cases, ensuring your regulatory compliance needs are met.

Celsius^® Single Use Platforms offer:

• Robustness by design: The Celsius^® bag-in-plate design uses Safecore™ Technology with materials chosen for their stable characteristics at low temperature.
• Scalable processes: Single-use bags are suitable for freeze and thaw processes from lab scale to manufacturing scale and adapted to different methods and equipment.
• Sterile assurance: An integrated tubing management system delivers aseptic connections, access to lines and cleanability.
• Sturdy shipping and handling: A complete solution keeps your product stable under real lifecycle conditions at -80°C.
• Validation: Decrease your validation work by using single use, freeze and thaw systems that include validation data across entire the entire lifecycle.

For biopharmaceutical companies looking to reduce costs, improve efficiency and strengthen regulatory documentation, switching from bottles to single-use bags makes sense – and improves stability of freeze and thaw applications throughout the product lifecycle, especially during scale-up.

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References

<sup>1. Kantor, et al. “Quality-by-Design for Freeze-Thaw of Biologics: Concepts and Application to Bottles of Drug Substance” American Pharma. Review, May 1, 2011.
2. Christoph Herwig et al., “Examining the freezing process of an intermediate bulk containing an industrially relevant protein”, Enzyme and Microbial Technology, 71 2015 : 13-19
3. Sandeep Nema et al., “Large-scale freezing of biologics – A practitioner’s review, Part one : Fundamental aspects”, BioProcess Int. 2009
4. FDA 21 CFR 211: cGMP for Finished Pharmaceuticals</sup>