I have an ongoing interest in Medical Device packaging. When I started at my current job a while back, my manager told me that the packaging operation is most critical operation for a sterile Medical Device. The product quality does not matter if the device is not provided sterile for the end user. The qualifications of new packaging configuration and the packaging process soon became my areas of interest.
The concept of “worst-case” is rooted in product reliability and good product design practices. The applicable industry standards for packaging Medical Devices are ISO 11607 parts 1 and 2. ISO 11607 part 1 has the following section detailing the use of “worst-case” product configuration for qualifying a packaging system.
“When similar medical devices use the same packaging system, a rationale for establishing similarities and identifying the worst-case configuration shall be documented. As a minimum, the worst-case configuration shall be used to determine compliance with this part of ISO 11607.”
For a Medical device design engineer or a packaging engineer, this determination of the worst-case comes natural. It is based on engineering judgment and intuition. However, one might find it easier if this can be documented objectively. The following matrix might be useful to document the worst-case configuration. Perhaps one can utilize a scoring system (1 through 5, where 1 -> Best case, and 5 -> Worst case) for each of the items detailed in the table below. Thus, the product with the highest score can be determined to be the worst-case configuration.
|1||Sterilization||2X sterilized represents worst case|
|2||Sealing||Low setting or edge of failure represent worst case|
|3||Mass||Heaviest product represents worst case|
|4||Size||Bulkiest represents worst case|
|5||Product geometry||Sharp corners represents worst case|
|6||IFU||Largest, heaviest, stapled IFU represents worst case|
|7||Product configuration||Most number of components inside represents worst case|
|8||Shipper quantity||Most number of units in the shipper represents worst case|
|9||Shipper compactness||Maximum room for pouches to move around represents worst case|
|10||Number of pouches inside sterile barrier||Maximum number of pouches represents worst case|
|11||Compactness inside sterile barrier||Maximum room inside between product and sterile barrier represents worst case|
|12||Pouch Used||Largest Pouch (largest pouch has largest seal area) represents worst case|
|13||Shipper Box Burst Strength||Low strength shipper box represents worst case|
Please note the worst-case for qualification tests may not always represent real life scenarios. However, qualifying using the worst-case provides assurance that the product can meet real life scenarios.
The scoring sheet sample can be downloaded here (worst-case score sheet).
Disclaimer: Please note that this post is purely based on my opinion and not to be used as advice. I shall not be responsible for any possible outcomes. Please use at your own discretion.