Shipping temperature-sensitive items, such as pharmaceuticals, vaccines, or biologics, presents unique challenges. Maintaining a constant temperature throughout the shipping process is crucial to preserving the potency and quality of these products.
Gel packs, also known as coolants, refrigerants, PCMs, or ice packs, offer a cost-effective solution for ensuring a reliable cold chain. In this blog post, we will explore the best practices for conditioning gel packs and optimizing their performance to safeguard temperature-sensitive shipments.
Understanding Gel Packs:
Gel packs are leak-proof containers designed to maintain the recommended cold chain temperature range inside a cold box or vaccine carrier. They are used in four different ways:
1. Frozen Solid Gel Packs:
Frozen gel packs are taken directly from the freezer and typically frozen between 20 degrees Celsius and minus-25 degrees Celsius. While they can keep the container temperature well below 0 degrees Celsius for several hours, they should not be used to transport temperature-sensitive products.
2. Conditioned Gel Packs:
Conditioned gel packs are warmed or thawed at room temperature until they melt and start to liquefy, usually around 0 degrees Celsius. This conditioning process eliminates the risk of initial freezing while maintaining the cold life of the gel packs.
3. Cool Gel Packs:
Cool gel packs are kept in a refrigerator without being frozen. While they eliminate the freezing risk, they may not provide the same cooling performance and protection as frozen gel packs.
4. Warm Gel Packs:
Warm gel packs remain at room temperature and are mainly used in extremely cold climates to prevent freeze damage to sensitive vaccines. This article will focus on frozen and conditioned gel packs.
Conditioning Frozen Gel Packs:
If you require frozen gel packs, it is essential to prepare them in a freezer that can maintain temperatures between 0 degrees Celsius and ultimately settle between minus-18 degrees Celsius and minus-20 degrees Celsius. This conditioning process eliminates the risk of thermal shock without reducing the gel packs' ability to stay cold. Consistency in the conditioning procedure is crucial to avoid exposing vaccines to freezing temperatures.
When placing gel packs in the freezer, ensure there is adequate air circulation around their two large, flat sides. This placement maximizes exposure to the freezer's airflow, enhances conditioning consistency, and minimizes the risk of product damage. Avoid snap freezing and prevent excessive airflow from reaching the gel packs' smaller sides when they are not on their large, flat face.
After the gel packs are fully frozen, remove them from the freezer and allow them to rest at room temperature on their large, flat sides until the ice starts to melt and liquid begins to develop. The conditioning process typically takes around 30 minutes at room temperature, but factors like light, gel pack mass, humidity, and air temperature can influence the time required.
Conditioning Gel Packs for Larger Applications:
For bulk shipping, such as crates or pallets, gel packs are often received as a full pallet with several cases loaded onto it. Conditioning full pallets may require several days, depending on factors such as mass, air circulation, and pallet stacking. The larger the mass and weight, the longer the conditioning time needed. Gel packs on the outer edges of the pallet will stabilize faster than those in the center. Planning for one to two weeks is advisable for a fully loaded pallet of gel packs to reach the desired temperature in a freezer or refrigerator.
Refrigerated Gel Packs:
When refrigerating gel packs instead of freezing them, ensure that the refrigerator's airflow is functioning properly and can cool all the loaded gel packs to a temperature between 5 degrees Celsius and minus-1 degree Celsius within the required timeframe. Avoid loading excessively warm gel packs into the refrigerator, as it can affect the temperature and hinder the cooling process. Consider the total gel pack mass rather than the number of individual packs when determining refrigeration times.
Guidelines and Support:
Finally, to comply with domestic and international pharmaceutical shipping standards and regulations, follow these basic rules:
- Ship and store products at the required temperature using qualified and validated shipping containers, vehicles, and facilities.
- Monitor the temperature throughout the shipping and handling process.
- Carefully inspect products for any signs of potential damage.
- Dispose of or return products if their quality is compromised.
- Maintain electronic records to validate the temperature stability throughout the entire process.
Properly conditioning gel packs is crucial for maintaining the integrity of temperature-sensitive shipments. Whether using frozen or conditioned gel packs, following the recommended procedures and guidelines will ensure optimal performance.
By paying attention to conditioning times, gel pack placement, and storage requirements, you can enhance the effectiveness of gel packs in preserving the quality and potency of pharmaceuticals, vaccines, and biologics during transportation.