ISO11607 defines and uses three seemingly similar terms: “Sterile Barrier System”, “Protective Packaging”, and “Packaging System”. These terms each have a distinct meaning and usage within the standard, and a precise understanding of the differences is critical when planning and executing packaging validations.
In this post we dissect the definitions and usage of these three different terms, and how the meticulous and intentional usage of each term within the standard affects your packaging validation.
ISO11607-1:2019 currently provides us with the following definitions, which have remained generally unchanged since their introduction into the document in 2006:
Sterile Barrier System (SBS) minimum package that minimizes the ingress of microorganisms and allows aseptic presentation of the sterile contents at the point of use
Protective Packaging configuration of materials designed to prevent damage to the sterile barrier system and its contents from the time of their assembly until the point of use
Packaging System combination of a sterile barrier system and protective packaging
As defined, the Sterile Barrier System – being the actual barrier to microorganisms, is the pouch, tray, or other barrier only – and nothing more. Any packaging elements besides the sterile barrier system, such as a backer card, protective sleeve, folding carton, retainer, corrugated case or foam cushioning would fall under the second definition, Protective Packaging. These are the items that protect the product and the sterile barrier system from damage – and sometimes from one damaging the other. Only when you combine the two elements; the Sterile Barrier System and the Protective Packaging, do you arrive at the Packaging System.
So why now would the standard go through the effort of creating these three very explicit definitions for our packaging? The answer is all through the standard, in how carefully the terms are used, and in the most specific detail, section 8 – Packaging system performance and stability.
The section begins by laying the general groundwork for the acceptance criteria for the performance and stability tests, by stating: “Sterile barrier system integrity…shall be performed after packaging system performance testing and stability testing…”. This is, in no uncertain terms, the acceptance criteria laid down for these two tests. Packaging system performance testing and stability testing are successful if, and only if, the integrity of the sterile barrier system is maintained. Any other testing is just supplementary – if it isn’t sterile, it doesn’t matter.
Section 8 continues into the requirements for the first of the two tests, Packaging system performance testing. This is where things really start to get fun for medical device packaging engineers; the transportation simulation. On this subject, the standard states “…The packaging system shall provide adequate protection to all sterile barrier systems and the sterile contents through the hazards of handling, distribution and storage…”. Carefully reading the section shows that this testing very explicitly applies to the Packaging System, which is a combination of the Sterile Barrier System and the Protective Packaging. This makes a lot of sense too – the whole point of the protective packaging is to protect the sterile barrier system and its contents from hazards, so it makes sense that the sterile barrier system, the contents, and the protective packaging are included in the test article.
As section 8 continues into the final requirement, Stability testing, there is a subtle change in how terms are used that should pique our interest. Stability testing is used to establish the shelf life of the Sterile Barrier System and per the standard: “…Stability testing shall demonstrate that the sterile barrier system maintains integrity over time…”. Did anyone do a double take there? The item in consideration is not the packaging system, it is the sterile barrier system. In fact, in the entire subsection 8.3 (Stability testing), the term “Packaging System” and “Protective Packaging” are not used once.
This is a very deliberate usage of terms. Yes, the protective packaging must protect the sterile barrier system and its contents during packaging system performance testing, but no – they cannot be expected to protect the sterile barrier system from time. The acceptance criteria for the stability test are the same as for the packaging system performance test: that the sterile barrier system integrity is maintained. In both tests, there are no defined acceptance criteria for the protective packaging in and of itself – it simply must perform its function during the packaging system performance test of protecting the sterile barrier system and its contents. Put simply – protective packaging is not included in the requirements for stability testing.
So, what does this mean for our package validations? Quite simply, it gives us additional consideration when executing Stability Testing on the Sterile Barrier System. Sterile Barrier System Stability Testing is one of the most time consuming studies for a new project, and is required to be done via real-time aging. It is also generally considered to only be conducted once for any particular sterile barrier system, and the results of testing can be used when designing other Packaging Systems. So much, that it is again explicitly described in the standard: “… Unless it is demonstrated that the contents adversely interact with the sterile barrier system, then previously documented testing shall be sufficient…”
This gives us considerable latitude to design new Protective Packaging and therefore new Packaging Systems without having to include the long-duration Stability Testing in our packaging development cycle, and therefore allows us to focus our efforts on bringing our life-saving and life-changing products to patients.
We are still required to execute Performance Testing on the complete Packaging System, and rightfully so. Additionally, when designing our protective packaging, we still must consider its ability to function throughout its projected lifespan, but when it comes to the actual acceptance criteria – maintaining the integrity of the Sterile Barrier System – the Packaging System Performance Test is where the Protective Packaging is put to the physical test.
As we end, let’s acknowledge how ISO11607-1:2019 provides us with a structured, meticulous guide for developing and validating medical device packaging systems and sterile barrier systems. Its clarity on definitions and testing criteria offers us the framework to innovate while ensuring sterility – a balance that’s crucial in our industry. Countless hours of volunteer effort have been gracefully donated by some of our industry’s most influential and talented individuals both to create and to maintain the standards that we use daily to assure our life-saving life-changing products are delivered into the hands of healthcare providers in a sterile state.