The pharmaceutical cold chain is subject to stringent qualification testing to ensure that solutions are fit-for-purpose. This is critical, given the need to protect the important products being transported.
With this in mind, it is surprising that one key item in the supply chain is not subject to these agreed, rigorous standards. Whereas most other parcel and pallet products are tested to rigorous standards like the ISTA (International Safe Transit Association) series, the same precision has not been applied to thermal covers.
However, at CCT we believe that thermal covers and related items should receive the same level of discipline and objectivity in testing, as other cold chain packaging solutions.
Understanding pharmaceutical thermal covers
It is easy to assume that all thermal covers are the same but in fact there are many types offering different levels of protection.
- Basic Thermal/Blanket/Cargo covers – Primarily act as protection against the elements and may offer limited heat or solar reflection.
- Reflective Solar thermal covers – Designed to provide protection against solar radiation and short-term temperature excursions, for example during exposure on the tarmac.
- Enhanced thermal covers with phase change materials (PCM) – Offer more robust protection by actively regulating temperature over a longer duration.
- Dual-protection solutions – Combine solar reflectivity and PCM-based thermal protection, delivering both short-term shielding from heat exposure and extended thermal stability.
What should industry standards in pharmaceutical thermal covers include?
A comprehensive, robust testing regime should take into account the different stresses to which cargo is subjected. Critically, it must be based on ‘worst case scenarios,’ with the focus on common failure points.
To this end, we recommend that industry standards in pharmaceutical thermal covers should be based upon:
- Using side-by-side solar testing to measure solar radiation reflection efficiency
- Using empty boxes, so that the product load doesn’t mask the real performance of the cover.
- Wide distribution of temperature probes
The case for solar testing
While chamber tests provide repeatable testing, they cannot account for solar radiation. Solar energy can be ten times more stressful to product temperature than just ambient temperature exposure. The International Air Transport Association (IATA) estimates 50% of temperature excursions occur during transportation, notably when pallets are exposed to the weather conditions on the tarmac.
To address the performance variable of solar energy, a “solar test” is vital to measure the reflectivity of thermal covers on the market. A thermal cover’s ability to reflect solar energy is an extremely important factor to consider, since there is so often the potential for sun exposure in real world scenarios.
A solar test needs the side by side comparison so that different pallets would be tested under the exact same conditions.
Understanding product loads
The type of product load used in testing can also dramatically affect test results. For example, a pallet full of thermal bottles will change temperature much more slowly than a product containing only air. Water requires four times more energy to increase in temperature when compared to air! Other types of thermal mass can be used, such as pills that could simulate drug products, but your blanket’s performance would still not be fully evaluated, as any thermal mass would ‘help’ the cargo cover’s performance.
Effective temperature probe distribution
Mapping the product load with temperature probes to cover all unique thermal locations is another extremely important step. It is common to place a probe in the center of the pallet, or the center of a box that is located on the top of a pallet. However, this type of placement is flawed, because it takes time for heat to penetrate the pallet from the outside edges. Accordingly, the product located on the edges will always warm much faster than product in the center of the pallet.
When considering how the temperature probes will be located on a pallet, you should evaluate the real stress that the product load goes through during shipment and distribute the temperature probes into spots of the pallet where the first failures usually happen.
Taking the lead on industry standards in pharmaceutical thermal covers
Since thermal covers do not have any industry accepted standardized tests, CCT has defined a set of unbiased criteria to assess and measure various thermal covers available in the marketplace – and the same approach is applied to thermal blankets. The goal of this exercise is to provide decision makers with relevant information to objectively compare the performance of various products.
You can see our initial testing taking place at CCT Madrid, via our LinkedIn update.
