The purpose of this article is to explain why you may choose an established ISTA profile in lieu of using a custom profile for OQ temperature validation studies. The established ISTA ambient profiles are industry tested and widely accepted globally, whereas custom profiles require a substantial amount of field data collection and can be quite costly to develop. Additionally with a custom profile you may run into issues where it is not accepted by a regulatory body internationally.
ISTA (International Safe Transit Association) thermal profiles are used in the Biopharmaceutical industry to simulate the temperature conditions a package may be subjected to during shipping. The goal of thermal OQ testing is to validate the performance of the shipper, this in turn ensures that the package’s contents are not impacted by variations in temperature that may degrade product quality attributes during transit. The right thermal profile depends on a wide array of factors, including the nature of the contents, the mode of transportation, and the expected route and duration of transit.
Here are some key considerations to keep in mind when choosing the right ISTA thermal profile for your package:
- Understand your product’s temperature sensitivity: The first step in selecting an appropriate thermal profile is to understand how sensitive your product is to temperature fluctuations. Different products have different temperature tolerances. It is important to select a thermal profile that falls within your product’s expected supply chain, so thermal lab testing can simulate how your product’s temperature may be affected during distribution. You may also want to consider the thermal mass of your payload in its expected shipping ranges, this will allow you to determine the viability of the shipping system more accurately.
- Determine the mode of transportation: The thermal profile you select will also depend on the mode of transportation. For example, ground transportation tends to expose packages to more extreme temperature fluctuations than air transportation, so you may need a more robust thermal profile for ground shipments.
- Know the expected route and duration of transit: The expected route and duration of transit will also play a role in determining the appropriate thermal profile. The duration of your transit will likely be one of if not the largest determining factor in your shipper choice outside of qualified temperature range. If your package is traveling through a region with extreme temperature variations, such as a desert or mountain range, you may need a more robust thermal profile that can test whether the intended shipping system can maintain your products’ required temperature range. This is normally determined by the ICH stability zones1 that your shipment will be moving through.
| Zone | Type of Climate |
| Zone I | Temperate Zone |
| Zone II | Mediterranean/subtropical zone |
| Zone III | Hot dry zone |
| Zone IVa | Hot humid/tropical zone |
| Zone IVb | Hot/Higher Humidity |
- Consider the type of packaging: From a risk-based approach, the type of product packaging and lack of existing shipping system qualification may recommend thermal testing. Some shipping systems manufacturers may have qualifications completed, but their qualifications will need to be reviewed against your product’s requirements and expected distribution lanes. Additionally, if you happen to be shipping on dry ice, you need to consider if your material is sensitive to CO2 ingress, in the event that it may be and this would affect product quality you would need to consider heat sealing the payload in mylar bags as an extra line of defense.
- Review ISTA’s available thermal profiles: Finally, ISTA has several thermal profiles available, ranging from relatively mild profiles to more aggressive profiles designed for extreme conditions. Reviewing ISTA’s available profiles can give you a sense of what might be appropriate for your product and situation. LBX recommends ISTA testing thermal profiles because of their robust nature and their wide acceptance around the world.
- ISTA 7D3: ISTA 7D is considered the more extreme temperature profile. ISTA 7D will have the package exposed to temperature changes ranging from -10°C to 35°C (-14°F to 95°F) The package is exposed to these conditions for an unlimited number of 24 hour cycles.
- ISTA 7E2: ISTA 7E was created after ISTA 7D, it was developed using an intensive data collection process and generally represents the gradual temperature changes that can be experienced throughout the day. ISTA 7E will have the package exposed to temperatures in the global heat and cold profiles. The testing profiles are run for either 72 or 144 hour durations but can be cycled if a longer profile duration is needed.
- ISTA 7D3: ISTA 7D is considered the more extreme temperature profile. ISTA 7D will have the package exposed to temperature changes ranging from -10°C to 35°C (-14°F to 95°F) The package is exposed to these conditions for an unlimited number of 24 hour cycles.
In conclusion, selecting an appropriate thermal profile for thermal OQ testing is crucial to ensure that a customer’s products contents arrive at their destination in the intended condition. LBX often chooses to use ISTA’s thermal testing profiles because of their long-standing credibility throughout the industry and around the world. By considering the factors outlined above, you can choose a representative profile that meets your product’s distribution network or supply chain and provide evidence that the proposed shipping system provides adequate thermal protection during transit.