While Summer dominates challenges for refrigerated and frozen pharmaceutical shipments in cold chain, Winter months are when considerations begin for the opposite end of the spectrum, CRT. Controlled Room Temperature (CRT) has become a broad term in cold chain and is highly dependent on the stability data of the drugs being shipped to define its storage temperature range. Ranges of 20-25°C, 15-30°C, 20-30°C, 2-30°C and 2-45°C are not uncommon to see as temperature requirements resulting in many complex systems being designed to accommodate the variety of ranges in an economical fashion. If a temperature excursion is to be avoided, real-world performance will ultimately depend on the phase change materials of these systems being conditioned correctly.
A Phase Change Material, or PCM, is any refrigerant used in cold chain shipping systems that has an alternate melting point to water. While pure water will freeze at 0°C, a PCM is designed to freeze at specific temperatures, commonly at -20°C, 5°C, 18°C, and 22°C. Often composed of blends containing paraffin oils (waxes), salts, and sometimes even cooking oils, the PCM can be engineered to melt at a specific temperature while keeping a freeze/thaw rate similar to water.
Shipping a CRT pharmaceutical typically utilizes a single PCM that has a melting point within the storage temperature range of your pharmaceutical. For example, if the product’s storage temperature is 20-25°C then a Phase 22 PCM might be utilized. The PCM will act as a sacrificial component that will have to freeze or thaw before your product will start to change temperature during transit. If the PCM is not in its correct state, then an excursion will occur.
The conditioning of a PCM can be strenuous for the typical pharmaceutical distribution. Freezers, refrigerators, and room temperature warehouses are utilized for a typical water-based gel pack, but these areas are usually too cold or uncontrolled to adequately condition a PCM. If funding is available, a thermal conditioning chamber can be purchased to ensure that PCM’s are either thawed for winter shipping or frozen for summer shipping. The initial investment is $80k or more for the thermal chamber, and multiple units will be required if multiple PCM types are used in an operation.
A refrigerator can be used in some cases to condition PCMs for CRT shipments. The refrigerator will ensure that the PCM is frozen, then a short benching or acclimation period at room temperature will bring the PCM back into your pharmaceutical’s required temperature range. This process can become cumbersome for larger scale operations since it has a two-step conditioning process and requires a benching study to determine the right amount of time the PCM must be in the ambient temperature before packing the cold chain system.
EFP has developed a method that can simplify these hurdles for you. By utilizing two separate PCMs, a Phase 18 and Phase 24, the PCMs can be left in the warehouse and can be prepared for either winter shipping or summer shipping. The Phase 18 will be in a thawed state and ready for any winter shipments while the Phase 24 will be in a solid state and ready for summer shipments. This method will also alleviate the dangers of unexpected cold environments in Summer like the hull of an airplane, or hot environments in the Winter like sitting in a hospital waiting to be unpacked. This method can be found in our Climatemp® Universal packaging solution and will ensure your high quality CRT pharmaceuticals stay within temperature specifications during transit.
Check out our Climatemp® solutions on our website and contact us today to learn more.
Written by Andrew Klasek, Thermal Design and Innovation Lab Director.
Andrew began his career in the Environmental Chemistry field before coming to the packaging world where he currently runs the EFP Cold Chain Laboratory which develops shipping solutions for pharmaceutical and food shipments. Andrew also participates in the creation of whitepapers and industry guidance documents with the ISTA Pharma Committee covering topics such as developing temperature profiles for testing, lane testing, and simulation software.
