Lesson #7: Cold Chain – Qualification vs. Validation
The nomenclature used for describing testing of cold chain packaging used to demonstrate its performance is somewhat controversial.
Here we discuss Qualification and Validation, the two most popular terms used to describe such testing.
Validation is documented testing, under highly controlled conditions, that demonstrates that a process consistently produces a result meeting pre-determined acceptance criteria.
Qualification is documented testing that demonstrates with high degree of assurance that a specific process will meet its predetermined acceptance criteria.
It is believed that the assumption used in decribing validation is that when a process has key variables which are considered controlled for the specific technology, that it can be considered validatable.
For example, for the heat sealing of packaging components, temperature, pressure and dwell time are considered key variables. With today’s technology, it is considered possible to control these temperature, by means of thermocouples, pressure sensors and digital timers, therefore very high degrees of repeatability are achievable with today’s heat sealing equipment. Such repeatibility is demonstrated by achieving 6 sigma type of reproducibility for this process, where 99.999% repeatability is achieved.
Going back to cold chain packaging, we should ask ourselves, what are the critical variables involved in heat transfer? Two key variables would be considered time and temperature differential. For the shipping application this would mean the length of shipment and the temperature of the environment – this also includes all the sub steps within the shipping process (truck time, air time, warehouse time, inside of a mailbox etc…).
With this in mind, if your particular distribution process is such that you have very good control of the time to ship and external temperatures, then depending on your thermal shipper technology and product requirements, you may be able to consider your cold chain shipping validated.
It is probably safe to say that for most shipping applications, it is too costly to build in this level of control in the distribution of products, therefore the length of shipment and external temperatures are not controlled enough to label the process validatable. In this case, and probably in most cases, it is proper to talk in terms of cold chain qualification.
It should be noted that as technology advances occur, especially with active and hybrid technologies, that in the future the controversy will be over and all pharmaceutical type of shipments will be validated.