By Wendy S. Mach, Packaging Section Leader, B.C., RM (NRCM), CQA(ASQ)
In Part 1 of our two part series on packaging, we wrote about the desire many medical device and packaging material manufacturers’ have to find ways to be more environmentally friendly and cost effective during these times of green initiatives and economic uncertainty.
Today we look at the various tests needed to validate medical device packaging. Whether for an initial validation or for a re-evaluation, there are a minimum of three categories that must be evaluated to validate a packaging process: Integrity, Strength and Microbial Barrier. Within each category there are a few different tests to choose from.
The standard requirements for materials, sterile barrier systems and packaging systems indicate that manufacturers chose one test from each category. Nelson Labs has developed a packaging matrix outlining the categories and test options available to manufacturers to meet the requirements. Click to see matrix.
The test options under the three categories include:
Integrity Category—these tests examine the overall integrity of the packaging.
- Bubble Emission Test—The bubble emission test is a ‘whole package’ integrity test. It is conducted by immersing the test package in a surfactant fluid and inflating the package to a specific pressure. Bubbles originating from a single point indicate a failure in the packaging integrity. This test is used for porous and nonporous packaging.
- Dye Migration Test—the dye migration test is conducted by injecting blue dye through the center of the package. The weight of the dye then presses against the seals of the packaging. If a seal is compromised, a visible blue channel is seen at the failed point in the seal.
Strength Category—these tests examine the strength of the packaging.
- Seal Peel Test—the seal peel evaluates the force required to open a package. It involves cutting a 1 inch segment from the selected seal and placing onto a tensile machine. The machine will then extend
continuously measuring the strength require to pull.
- Burst Test—this test provides two pieces of information: it identifies the weakest seal on the package and provides the pressure needed to compromise or burst the seal. This test is especially important in assuring packaging can withstand the rigors of extreme altitudes such as regional elevation or air transit. The test is conducted by placing the package onto a probe and attaching it to the machine. The air pressure will increase until burst.
In conjunction with the burst test, a creep test can be conducted. The creep test is similar to the burst test, but instead of increasing pressure until it bursts, the package is pressurized for an extended period of time. The set point for this test is 80 percent of its burst pressure. This test determines if the weak seal will slowly ‘creep’ to a burst.
Microbial Barrier Category—these tests examine that the packaging is providing a barrier against microrganisms.
- F1608 Microbial Ranking—this test provides a log reduction value of the organisms penetrating packaging material and can only be conducted on porous materials. The test involves taking a 47 mm disk of the porous material and exposing it to aerosolized organisms. The test then determines how many organisms were able to pass through the material. The result is a Log Reduction Value (LRV) that converts into an efficiency rating. For example, a 6.0 LRV equates to a 99.9999 percent efficiency rating.
- Whole Package Aerosol Challenge—this test is follows the concept outlined in the F1608 test, but instead of a material sample disk it tests the entire package. The test is conducted by taking a whole, sterilized package, hanging it in a chamber in the non-critical seal area and spraying the chamber with aerosolized indicator organisms. The organisms fall on the package. The package is then decontaminated after which the package is aseptically opened and the contents tested to determine if the indicator organism penetrated the packaging.
The Food and Drug Administration requires manufacturers to “ensure that device packaging and shipping containers are designed and constructed to protect the device from alteration or damage during the customary conditions of processing, storage, handling and distribution” *. Understanding the validation tests can help manufacturers better develop packaging that will both protect their product and meet FDA requirements.
*Code of Federal Regulations, 21 CFR Part 820, Sec. 130; Current Good Manufacturing Practice (cGMP) For Medical Devices and In Vitro Diagnostic Products.