Lesson #8: Cold Chain Qualification – Temperature profile selection
Temperature profile selection for cold chain qualification is a topic of much discussion for the pharmaceutical industry.
A temperature profile describes the external temperatures used to challenge a thermal shipper in a laboratory test, therefore providing evidence of performance when testing against extreme conditions.
The question is what should these extreme conditions be to fully represent expected external conditions. While there is no easy answer, the following is a recommended approach:
1-Standard profiles: If starting from scratch, where no data is available for a specific distribution lane, usage of standard temperature profiles may be advisable. The drawbacks of such actions are fairly obvious, since it may be difficult to justify the use of a standard approach for something for which no stanrdard really exists, such as the distribution steps and environmental temperatures a package experiences in transit.
This said, it is preferable to test against standard profiles since these would be considered third party recommendations. This is something that can be implemented fairly quickly, by testing your package in a laboratory unders this standard conditions.
An organization which provides standard temperature profiles is ISTA (Internation Safe Transit Association)
2-Climatic Data: the next logical step in the evolution of a temperature profile strategy should involve the careful geographic evaluation of the specific distribution lanes involved.
This could include determining the countries, regions, states or even cities from, to and through which shipments take place – obviously the more detail the better, however complexity is increased with increased detail. Then, using third party resources which collect environmental data (such as NOAA in the US), replacing environmental temperatures from standard profiles, for the extreme temperatures experienced in the specific regions.
Obvious drawbacks to such an approach are the justification of correlation between climate data and the temperatures experienced by your packages. For example, in some cases, climate data for summer conditions may not reflect the temperatures inside of a mailbox or a truck exposed to the sun, where other effects may induce more extreme temperatures when compared to climate data.
3-Actual Shipment Data: the next logical step now involves performing actual shipments, over at least a year, and capturing the environmental data experienced by the shippers. This is clearly the most costly and lengthy approach, but it also yields the most defendable data, especially if it is followed up by continuous monitoring even after completion of a study, to account for potential changes such as global warming, or changes in the way product is distributed (such as switching from a brown truck to a white one or viceversa).
The process of collecting such data should be performed with care and scientific rigor, to assure the validity of said data. For example the design of the test box could have an effect on the data collected, such as the color, size, weight and venting used for the test shipper.
It should be noted that how critical temperature profile selection is depends on several factors, such as mode and length of travel, type of product and type of technology used in the thermal package.
For example, for a short shipment of liquid product with broad stability profile, shipping between two temperate locations, using an active thermal system, the temperature profile selection would be considered less critical than for an international shipment of a powder with narrow stability (2-8ºC), shipping between two locations with extreme temperatures using a passive thermal system.