The rapid strides made in COVID vaccine manufacture have prompted much greater media awareness of the term “cold-chain handling.” The challenges of cold-chain handling are not new to the pharmaceutical industry, however – nor are they limited to vaccines. Conventional single-use polymer-based containers can become brittle and break under the extreme cold temperatures often required when transporting drug substances, which may result in significant costs to manufacturers due to product lost through container failure.
 
This has led the industry to seek out more robust solutions for single-use cold-chain containers, including containment made with polytetrafluoroethylene (PTFE) fluoropolymers. Containers made from PTFE may be less susceptible to mechanical failure and breakage than conventional materials, such as EVA or Polyethylene.
 
The cold-chain challenge and its financial implications
Temperature-sensitive drugs, including some vaccines and other biopharmaceuticals, require temperature-sensitive handling. Challenges associated with cold-chain handling in pharmaceutical manufacturing and logistics, including transportation and proper storage, can be very expensive. Biologic drug substance storage and transportation requires temperatures ranging from 2 degrees to -80 degrees Celsius. Many forms of drug containment, such as conventional polymer bottle and bags, face challenges – including breakage – at such temperatures.
 
Despite their wide use throughout the process, conventional polymers used for single-use products in cold-chain handling can fail at cold temperatures. Materials may become brittle, resulting in possible breakage or leakage at below-freezing temperatures.
 
Drug product lost due to container breakage can be costly for the drug industry and devastating for patients who may need or rely on the drug product. By some estimates, 3% to 5% of conventional containers fail during cold-chain handling. The cost of a biologic drug substance could range from $10,000 to $500,000 per liter, afailure rate of 3-5% is a significant amount of money lost to waste. Given the anticipated growth in temperature-sensitive biologic drugs such as monoclonal antibodies, antibody drug conjugates, and bio-engineered vaccines in the coming years, the industry has begun to look for solutions to these financial and logistical challenges. One solution being used is polytetrafluoroethylene (PTFE), a type of temperature-resistant fluoropolymer with chemical properties that make it a better option for cold-chain handling containers.
 
The benefit of fluoropolymers in cold-chain handling
PTFE is bio- and chemically inert, with a low coefficient of friction. It also is chemically stable and non-particulating, with a low extractablesprofile. The structure of PTFE can be manipulated to control its physical properties and can be combined with other materials to create functionality for specific uses.
 
Among the products introduced into the cold-chain handling aspect of pharmaceutical manufacture is the GORE® STA-PURE Flexible Freeze Container. These flexible, single-use storage containers are impact and crack resistant, even after freezing at -86°C (-123°F) and maintain a low extractables profile.
 
For example, frozen impact durability testing includes freezing the product in a freezer at -86°C and dropping onto a concrete floor from a height of 36 inches. Freeze/thaw cycling tests should include storing the product in a freezer at -86°C for five cycles and thawing it in a water bath at room temperature. Even in long-term frozen storage testing, where the product is stored in a freezer at -86°C for 12 months, integrity is not compromised. These single-use PTFE products offer the flexibility required of cold-chain handling packaging.