What is the procedure for an accelerated aging test for medical devices?

In accelerated aging tests for medical devices, a material or Sterile Barrier System (SBS) is exposed to elevated temperatures for a condensed amount of time. By exposing the testing materials to more extreme conditions during a shorter time frame, researchers can evaluate how a product will age under normal conditions without waiting for the entire desired duration.

Armed with this knowledge, manufacturers can determine shelf life, storage, in-use, and transportation parameters more accurately for their product.

Accelerated aging is a standard practice in the medical device industry for determining shelf life parameters by accelerating the effects of time on a Sterile Barrier System (SBS). The accelerated aging process is based on the relationship between temperature and reaction rate, in which the reaction rate increases as the temperature rises.

The Arrhenius Equation is the basic formula used for an accelerated aging test for medical devices is:

Accelerated Aging Time ​(AAT)= Desired Real Time (RT)Q10​[(TAA−TRT)/10]

NOTES

• The calculated AAT is typically rounded up to the nearest whole day.
• Westpak does not recommend aging packaging materials at temperatures exceeding +60ºC. Common Accelerated Aging temperatures (TAA) are +50ºC, +55ºC, and +60ºC.
• Ambient temperature (TRT) is typically between +20ºC to +25ºC. A temperature of +25ºC is a more conservative approach.
• The aging factor is typically between 1.8 – 2.5 with a value of 2.0 being the most common value.

To perform ASTM F1980 accelerated aging tests for medical devices, the laboratory facility must identify the Q10 value of the testing sample. The Q10 temperature coefficient is a measure of how quickly a material system changes when the temperature is increased by +10°C.

What are some of the parameters for ASTM F1980 testing?

ASTM International sets forth specific test parameters to ensure consistent testing across different lab facilities. The basic parameters for ASTM F1980 include the following:

• The quantity of product testing samples is specified
• Using the Arrhenius Equation, the TRT should accurately reflect the actual product storage and in-use conditions, generally between 20°C and 25°C.
• Accelerated aging temperature should be identified prior to testing. This is done by having in-depth knowledge of your materials, product, and packaging. It is not recommended to exceed +60°C.
• The need for controlled humidity during accelerated aging should be identified prior to testing; if materials are subject to moisture degradation, 45% – 55% RH is suggested. This input should be determined with your material providers’ assistance.
• A Q10 factor needs to be determined, which involves testing materials at various temperatures and defining the differences in reaction rate for a 10° change in temperature. A typical Q10 factor used during testing is 2.
• Accelerated aging factor should be specified using the following equation:

AAF = Q10 (TAA-TRT)/10

What is the best temperature to use for an ASTM F1980 test?

The ASTM F1980 standard suggests using an accelerated aging temperature below 60°C. Aging your product at a greater temperature provides the advantage of a faster simulation of the aging interval, but this comes with risks for particular products and packaging materials. Medical devices are often engineered with delicate materials that may drastically change when exposed to temperatures exceeding +60°C. Finding out if your medical product or device may be adversely affected by long periods of high heat or low humidity is a good place to start when choosing the best accelerated aging temperature.

Westpak’s experts can help you define the ideal temperature parameters for your products and packaging.

Does the F1980-21 version require using controlled humidity during accelerated aging?

In short, humidity is not a required element of accelerated aging. The recent version suggests that humidity conditions in the aging study be defined before starting aging studies. If RH will not be controlled, the rationale for exclusion should be documented.

What is the best humidity level to use for accelerated aging?

Humidity usage is dependent on the materials used in your product and packaging, how moisture impacts them, and other environmental factors. If humidity during accelerated aging is to be controlled, Westpak recommends conferring with our sales team to determine the RH level to be specified in the test plan. Also, as per F1980-21, the rationale for uncontrolled humidity should be documented.

How do you evaluate the ASTM F1980 test, post-aging?

After a testing sample has undergone the accelerated aging process, its physical properties and package integrity will be compared against various aging time points. This includes visual inspections per ASTM F1886, and sterile integrity testing such as Burst, Bubble, Dye and Peel testing. You will want to test at all time points noted on your packaging shelf-life label.

When this process is complete, Westpak will deliver a comprehensive report specifying the aging conditions and testing standards applied, as well as document the equipment used. Finally, we’ll detail the outcomes of the post-aging tests, and any statistical methodologies utilized to establish whether the sterile barrier system fits the performance specifications for the product.
When this process is complete, Westpak will deliver a comprehensive report specifying the aging conditions and testing standards applied, as well as document the equipment used. Finally, we’ll detail the outcomes of the post-aging tests, and any statistical methodologies utilized to establish whether the sterile barrier system fits the performance specifications for the product.

My products must comply with the new F1980-21 revision. What do you recommend?

Whether you have a released medical device or a new product in development, Westpak’s sales experts can help. Our recommendations will be based on your company’s unique product, market, and any special requirements.