How do you conduct accelerated stability testing to predict shelf life?

From a small molecule Pharmaceutical perspective. This is factually incorrect and potentially misleading. Accelerated testing is done at a higher temperature and higher or lower humidity depending on the dosage type on the drug that the consumer sees (final packaged drug). It does not concern lower levels of temperature, nor light, pH or other factors - those are held under stressed conditions, see ICH Q1A for further reading.

I disagree with the categorical statement that lower temperature storage should not be considered an accelerated condition. In some cases, phase changes can occur at lower temperatures that can result in altered morphism of the active molecule or even other excipients in the formulation, leading to enhanced degradation or loss of critical product attributes such as potency, partitioning, or solubility. It really depends on the molecule and the formulation. Many vaccines, such as alum-adjuvanted subunit vaccines can be drastically impacted by prolonged storage below optimal temperatures or by repeated phase changes.

As it relates to medical devices, I actually disagree with the statement "The purpose of these tests is to accelerate the degradation or deterioration of your products, helping you identify the critical factors that affect their stability and performance." The purpose of the stability testing is to study the effects of simulated environmental conditions on the performance parameters of the device to determine if the device can be considered stable for pre-defined periods.

Accelerated testing for devices is required per the standards for medical devices. However, real time stability testing must also be performed in parallel to accelerated testing per the ISO/FDA guidelines. The stability testing supports labeling of the medical devices as well.

I agree accelerated testing is important. It does not necessarily comply with GMP regulations and guidelines. Accelerated stability testing is generally not done for approved drugs unless there is a change to warrant such a test. It does help you optimize the formulation, packaging toward the storage conditions but often times stressed stability is used for initial formulations. It does NOT reduce the cost nor time of long-term stability testing which does take years to complete. The long-term stability testing remains the gold standard in the small molecule pharmaceutical industry.

Accelerated testing is useful in developing guidelines and metrics that can be used to evaluate the impact of deviations from the labeled storage conditions, such as may occur during packaging, shipping, and in-field handling. If degradation kinetics are known across a range of potential exposure conditions, it is possible to construct a mean kinetic model that can be used for estimation of the impact of deviated conditions on critical product attributes. Additionally, knowing the expected kinetics of degradation for a drug and formulation, applying accelerated conditions to product lots can provide early warning of impending lot specification failure to guide product distribution and recall surveillance.

Arrhenius equation AND the Eyring equation can both be used to determine the effect of temperature vs reation rate. There is no Q10 equation in ICH Q10. This section appears to be far more GMP than regulatory again this should be based in ICH Q1A. Typically we do not vary test parameters, nor the variation. The duration and frequency of the accelerated stability test is generally 6 months at a minimum of 0,3,6 months with additional points often added to as much as 0,1,2,3,6 months.

Alternatively you can rely on applicable ISO standards for shelf life of medical device you intend to verify stability for testing parameters, samples sizes, etc.

For the US, small molecule generic pharmaceuticals use a general paradigm that 3 (now 6) months accelerated at 40C = 24 months (or more) long term expiry at 25C. This is generally NOT accepted in new drugs in the absence of adequate long term data. For most small molecule drugs expiry, the panoply of long term stability data is pooled and statistically examined rather just using the accelerated data to predict using mathematical modeling an expiry.

For most medical devices, all performance requirements must be met post environmental conditioning at defined intervals (usually 6months, 1yr, 2yrs, 3yrs and 4yrs.)

Real-time monitoring solutions are important for data collection, and they can prevent deviations that could ruin your data set along with your samples. Vaisala is a common solution for data collection and meets many industry regulations, but whatever solution you use make sure it is properly installed. Consider wireless solutions as they are easy to deploy and expand.

Accelerated testing is based on modelling and the model should be referenced when presenting the results. Where does the use of real-time data to confirm the model come into this process? What steps are taken if the model doesn't predict the actual stability?