Accelerated stability test

Accelerated stability testing involves subjecting a product to extreme environmental conditions (high temperature, high humidity, light exposure) to simulate natural aging and assess its long-term resistance .
This test allows for the prediction of a product's shelf life and the rapid identification of instabilities that could compromise its quality, appearance, efficacy, or microbiological safety.

Typically, the standard conditions applied are 40°C and 75% relative humidity (RH) for a period ranging from 4 to 12 weeks , depending on the nature of the product and the applicable standards (ICH, ISO, NF, etc.).

The accelerated stability test is based on the principle of chemical kinetics : degradation reactions are accelerated at high temperatures and humidity, allowing estimation of the degradation that would occur over several months or years at room temperature.

Test methodology

The samples are placed in climate-controlled chambers simulating extreme conditions of temperature, humidity, and sometimes light.
At regular intervals (e.g., 0, 2, 4, 8, 12 weeks), analyses are performed to monitor the product's evolution according to various criteria:

• Visual appearance and color (physical stability).
• pH, viscosity, density, active ingredient content (physico-chemical stability).
• Microbial counting, molds and yeasts (microbiological stability).
• Oxidation, rancidity, precipitation or phase separation depending on the nature of the product.

These results make it possible to determine the degradation curve and to anticipate the risks of non-compliance before marketing.

For cosmetic or nutraceutical products, the test may be supplemented by specific studies such as:

• The photostability test to evaluate resistance to UV light.
• The container-product compatibility test to verify the interaction between the formulation and its packaging.
• Evaluation of the oxidation stability of fats and oils for lipid-rich products.

Matrices and application domains

Accelerated stability testing applies to a wide range of products:

• Nutraceutical products : food supplements, powders, capsules, dry extracts, herbal formulations.
• Cosmetic products : creams, gels, oils, serums, lotions, sunscreens.
• Chemical and technical products : formulated solutions, polymers, surfactants, solvents.
• Agri-food products : fortified foods, functional formulations or processed products sensitive to heat.

This analysis is essential to validate the stability and conformity of products before they are placed on the market.

Industrial and regulatory applications

Accelerated stability testing is used at all stages of a product's life cycle:

• Research and development (R&D) : rapid evaluation of the robustness of a formulation.
• Formulation optimization : identification of unstable or incompatible ingredients.
• Regulatory validation : requirement of certain authorities (ANSM, EFSA, FDA, ISO 11930) for registration or placing on the market.
• Quality control : monitoring the stability of production batches and validating shelf life.

It constitutes an essential step in the technical stability file , guaranteeing the safety, performance and reliability of the product throughout its marketing period.

Interpretation and use of results

The results obtained make it possible to identify the dominant degradation mechanisms (oxidation, hydrolysis, enzymatic degradation, etc.) and to deduce the estimated lifetime (t₉₀) corresponding to the maximum tolerated loss of performance or concentration.

In parallel, long-term stability studies can be undertaken to confirm the hypotheses derived from the accelerated test. This data is essential for establishing the best before date (BBD) or the period after opening (PAO) .

YesWeLab's expertise

YesWeLab provides access to a network of partner laboratories accredited to ISO 17025 and COFRAC standards , specializing in stability testing, accelerated aging tests, and physicochemical analyses .
Our experts support manufacturers, formulators, and engineering firms in:

• The design and monitoring of accelerated stability protocols .
• The scientific interpretation of the results and the modeling of storage durations .
• Validation of formulas before marketing or regulatory registration.

Thanks to the YesWeLab digital platform , managing your tests is simplified: submitting quotes, tracking samples and accessing test reports online.

For any specific request, contact our scientific team now to benefit from complete support in the design and validation of your stability tests.