7 Tests Vital to Package Validation

The package validation process includes a number of tests designed to ensure that the package has the strength and integrity to survive the hazards inherent in the distribution, handling and storage environments.

More information on the testing and requirements needed for medical device package validation can be found by listening to DDL's series of ISO 11607 Revisions Webinars. This series of 3 Webinars is now available on-demand.

Here are 7 tests vital to the package validation process.

Package Strength

TEST 1 - SEAL PEEL TESTING

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This test is the most common means for evaluating the quality of the package seals. The primary means of characterizing package seal strength is to measure the force required to separate two packaging components. Such a separation may be part of the package design, in order to facilitate aseptic presentation, or it may represent the force required to rupture a permanent (or “weld”) seal. In either case package seal strength measurements are key indicators of the package formation process and quality.

The sealability of the material combinations under evaluation should be tested in the laboratory using a range of conditions designed to demonstrate extremes in seal strength and quality. These seals should be tested for tensile peel strength and reviewed to determine if the results meet the desired seal strength for the package system. This process is typically used as a screening tool for selection of material combinations and may be used to evaluate pre- and post-sterilization seal strength. Thereafter seal strength measurements are used to monitor manufacturing and to ensure a process is in control.

To perform seal peel testing, a tensile testing machine pulls apart two “legs” of a precision-cut seal section at a controlled rate of separation, measuring separation distance and tensile load during the process. Typically, seals are tested at several points around the package perimeter. There are several techniques for peeling the sample such as; 90 degree unsupported tail, 90 degree supported tail, and 180 degree with a backing plate. Any of the techniques can be used, but must be specified and documented.

Package Integrity

Package integrity is the essential aspect of an effective medical device and is the ultimate acceptance criteria for a satisfactory package.

The package provides confidence that the device remains in a sterile condition to the point of use, and facilitates the aseptic delivery of that device. In most cases, loss of sterility is regarded as an event-related phenomenon. In other words, it occurs only in conjunction with a physical breach of the package caused by a dynamic event. So, it is critical to ensure a package provides a proper level of device security, and that an inspection of that package can dependably serve as a measure of sterility maintenance.

Test methods associated with package integrity involve probing for physical breaches in the microbial barrier, due to either the failure of a package seal or the failure of the material itself.

TEST 2 - BUBBLE LEAK TESTING

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Bubble Leak Testing using methods like ASTM F2096 involves submersion of a package in a fluid and the application of a pressure differential. An occurrence of a steady stream of air may indicate the existence of a leak. The methods are best suited for gross leaks and are commonly applied to packaged products that have been subjected to actual or simulated shipping conditions to assess package integrity.

TEST 3 - LEAK TESTING BY DYE PENETRATION

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This test is performed by injecting a quantity of dye solution into the package and then allowing it to contact all of the seals of the package. If a channel is present in the seal, the dye will easily flow through the channel in a matter of seconds. If the dye is held too long in one place it will eventually ‘wick’ through the porous material.

Distribution Simulation

Since package integrity is often compromised by the hazards inherent in the distribution of a product, it is important to simulate the transportation and distribution in the lab.

A common procedure for simulating the distribution environment in the laboratory is the standardized test designated as ASTM D4169. Distribution Cycle 13 for “Air and motor freight for packages up to 100 lbs” is often used as a typical mode of transport for medical device packages.

TEST 4 - DROP TESTING

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The first test in the distribution simulation sequence is the drop test.

TEST 5 - COMPRESSION TESTING

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Compression testing simulates the loads that may be applied to a package in transit as other packages are placed on top in the loaded truck.

TEST 6 - REPETITIVE SHOCK TESTING

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This test subjects the package to a series of low level shocks using the rotary motion shaker table.

TEST 7 - RANDOM VIBRATION TESTING

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Random vibration testing is a combination of simulated but realistic truck and air vibration inputs. The vibration inputs are produced from actual recorded field data that has been statistically analyzed and converted to a command signal that, when played into the test machine, produces similar random vibratory motions to those seen in the transport vehicles.