Accelerated Aging is a testing method used to estimate the useful lifespan of a product when actual lifespan data is unavailable. This occurs with products that have not existed long enough to have gone through their useful lifespan. A product can be released to market based upon successful Accelerated Aging of the package/product that simulates the period claimed for product expiration (1 year, 2 years, etc). Accelerated Aging data is recognized by regulatory bodies as an acceptable means to generate data quickly, but is only accepted until those tests can be repeated on "real time" samples.
An Accelerated Aging test is carried out by subjecting the product to unusually high levels of stress (rapid, but controlled, changes in temperature, humidity, pressure, strain, etc.) designed to mimic the effects of normal use. Mechanical parts are run at very high speed, far in excess of what they would receive in normal usage. Polymers are often kept at elevated temperatures, in order to accelerate chemical breakdown.
Accelerated Aging techniques are based on the assumptions that the chemical reactions involved in the deterioration of materials follow the Arrhenius reaction rate function. This function states that a 10° C increase or decrease in the temperature of a homogenous process, results in approximately a two times or ½ time change in the rate of a chemical reaction. For example, at 55 °C, 6.5 weeks is equivalent to 1 year on-the-shelf, and at 55 °C, two years would be equivalent to 13.0 weeks and five years would be 32.5 weeks.
The primary reason for using Accelerated Aging techniques in the qualification testing of a medical device is to bring the product to market at the earliest possible time. The goal is to benefit both the patient-for example, through early availability of a life-enhancing device-and the company-by generating additional sales and market share-without exposing either to any undue risk. Although Accelerated Aging techniques are well documented in academic circles, information on the use of these techniques in medical product testing is somewhat limited.
Testing includes, but not limited to, the following:
- ASTM F1980
Standard Guide for Accelerated Aging of Sterile Barrier Systems for Medical Devices
- ASTM D4332
Standard Practice for Conditioning Containers, Packages, or Packaging Components for Testing
- ASTM F1327
Standard Terminology Relating to Barrier Materials for Medical Packaging
This Accelerated Aging Calculator provided by Medical Package Testing, a division of Life Science Outsourcing, Inc.
Definition of variables:
- AAR: Accelerated Aging Rate
- AATD: Accelerated Aging Time Duration
- DRTA: Desired Real Time Aging
- AAT: Accelerated Aging Temperature
- AT: Ambient Temperature
- Q10: Accelerated Aging Factor
- Q10 = 2 (industry standard)
- Q10 = 1.8 (more conservative option)
AAR = Q10(AAT - AT) / 10)
AATD = DRTA / AAR
Time duration calculation for accelerated aging of a medical product:
One year shelf study at 55 degrees Celcius, where ambient temperature is 22 degrees Celcius and Q10= 2
|AAR = Q10((AAT - AT) /10)||AAR = 2(55 - 22 )/ 10) = 9.85|
|DRTA = 1 year x 365 = 365 days|
|AATD = DRTA / AAR||AATD = 365 / 9.85 = 37 days|
NOTE: 55° C AAT and Q10 =2 are the most commonly used factors for medical devices and medical packaging components.
Accelerated Aging Calculator
This calculator generates a table of values for calculations based upon ASTM F1980, Accelerated Aging of Sterile Medical Device Packages.