Document All Packaging Decisions, Says MD&M West 2011 Speaker

When developing medical device packaging, documentation can be a packaging engineer’s best friend. You have got a lot of decisions to make, and you may be asked to justify them one day.

At MD&M West 2011’s day-long packaging session for medical device manufacturers, Abhishek Gautam, CPP, staff packaging engineer at Edwards Lifesciences, stressed the importance of understanding product requirements and documenting all packaging decisions. He presented a multistep approach to designing packaging for medical devices in “Vacuum Formed Sterile Barrier System: Concept to Production Lifecycle.”

Abhishek Gautam, CPP, staff packaging engineer at Edwards Lifesciences

During the first stage, which Gautam called “Attribute Definition,” packaging engineers should thoroughly collect package design attributes, Gautam explained. “Depending on complexity of a project, this could take a year,” he told the audience. “You want to be sure to document all requirements. If your collection is incomplete or poorly documented, package integrity could be impacted down the line, resulting in user complaints and product damage.”

Engineers could be hit with a lot of requests from various functional areas, so Gautam said that segregating requirements into two lists—must-have and nice-to-have attributes—can help prioritize them. “Must haves are critical package design requirements without which the package’s function cannot be achieved,” he explained. “Nice to haves include less critical elements that you can weigh against time and cost considerations.”

During stage two, or “Conceptualization,” engineers translate package design attributes into technical specifications, Gautam told the audience. “At this stage, you are looking for the ideal forming material, grade, and gage thickness, for instance. You will identify critical dimensions and need to consider geometry, radii, and depth of part.” You’ll be reviewing 3-D models, getting feedback, and documenting everything, he added. In the case of developing a vacuum-formed tray, you will be signing off on premolds and prototype drawings, he said.

Engineers must also determine whether a male or female mold will be utilized. “Using female molds, the thickest part of the tray will be the seal flange,” he explained. “But in using male molds, the thickest part will be at the bottom of the tray. You need to decide what is more appropriate for your product, and document it.”

Since the molds for a vacuum-formed part typically feature intricate designs, engineers need to be confident in those designs before approving production tools, Gautam advised. During what Gautam called Stage 3A, or “Mold Design,” engineers may want to consider trying a “metal pilot tool first,” he said. “It gives you the chance to change and consider the type of material, size, type of equipment, number of cavities, and shrinkage factors before you lock in your design.” It can also be used to produce parts for “voice of customer” studies, he added.

During mold design you will also be identifying critical dimensions, which impact design functionality. “You need to determine where you need to hold the tightest process tolerances,” he said. Other decisions to make (and to document choices) include determining the following:

•    Location of vacuum channels.
•    Angles and tapering for part removal.
•    Use of a heat element in the mold.
•    Drying time.

“You will need to agree on process tolerances with your suppliers,” he stressed.

Stage 3B, or “Mold Qualification,” draws from ISO 11607, Part 2, which states that forming, sealing, and assembly processes must be validated. Before qualifying the mold, IQ/OQ/PQ (installation qualification/operational qualification/performance qualification) must be conducted on forming equipment; materials must be qualified and subjected to DOE studies and subsequently process validated, Gautam explained.

There are many ways to qualify a mold, he explained. Engineers must run a sufficient amount of material and produce enough parts to “capture process variability, he stressed. “Pull parts at defined intervals,” he explained. “Then perform your first article inspection and perform form, fit, and function reviews and measure critical dimensions for a statistical analysis.” Other considerations include determining acceptance criteria for mold qualification and selecting, qualifying, and calibrating measurement systems. At the end of this stage, engineers will have finalized process tolerances and signed off and ordered final parts.

Gautam calls Stage 4 Implementation. “Here is where you determine whether your design will meet ISO 11607. “Your supplier’s drawing and your internal drawings must match,” he said. “If so, the result is a qualified part!”

Engineers must settle on incoming inspection measurement systems as well as statistically valid sampling plans. “Every process or design change must be made according to ISO 11607,” he concluded.

For details on upcoming events for medical device manufacturers, visit http://www.canontradeshows.com/expo/mdmshows/.