Can Shelf Life Testing Be Dissociated From Transit Testing?
For medical device package validation, shelf life testing and transit simulation are often treated as entirely separate issues. But can we really be so quick to separate the two?
Well, it depends on the package undergoing transit and shelf life testing. Part of the answer will lie in your particular distribution cycle. Where is the product stored for most of its shelf life; in the factory, with distributors, or at the customer’s store? It is probably safest to assume that a product can travel long distances right at the end of its shelf life.
If you wait 30 weeks for Accelerated Ageing to deliver five years real time equivalent ageing, and then conduct the transit testing, you have just delayed your product launch by around 9 months.
The rationale here could be: ‘We can show that the seals are strong and integral after five years of ageing and that they are resistant to transit whilst they are strong and integral. Therefore is does not matter at what time point the transit simulation is carried out.’
There are two main routes to transit simulation. The simplest and lowest cost route is to use the ISTA methods. For medical devices this usually means procedure ISTA 2A (used for cartons with a mass up to 150lb). An alternative route is through test method ASTM D4169.
Accelerated Ageing for stability and shelf life testing is described in ASTM F1980. This standard relates ageing at elevated temperatures to real time equivalent ageing at ambient temperatures. A calculator is available Accelerated Ageing page.
Once transit simulation (and/ or Accelerated Ageing) is complete, the primary package sterile barriers should be challenged for seal strength and integrity - that is, maintenance of sterility. There are a variety of methods for these tests. Which one to use depends upon the blister or pouch design and materials.
To find out more about our shelf life testing services, please fill in our contact form, or give us a call on 0845 458 8924.