Accelerated stability test

Accelerated stability testing involves subjecting a product to extreme environmental conditions (high temperature, high humidity, light exposure) in order to simulate natural aging and assess its resistance over time .
This test makes it possible to predict the shelf life of a product and quickly identify instabilities that could affect its quality, appearance, effectiveness or microbiological safety.

Typically, the standard conditions applied are 40°C and 75% relative humidity (RH) for a period varying 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 humidities, making it possible to estimate the degradation that would occur over several months or years at room temperature.

Test methodology

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

• Visual appearance and color (physical stability).
• pH, viscosity, density, content of active ingredients (physicochemical stability).
• Microbial count, 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 anticipate the risks of non-compliance before marketing.

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

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

Matrices and application areas

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 : enriched foods, functional formulations or heat-sensitive processed products.

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 assessment 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 marketing.
• Quality control : monitoring the stability of production batches and validation of shelf life.

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

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 arising from the accelerated test. These data are essential for establishing the best before date (BBD) or the period after opening (PAO) .

YesWeLab expertise

YesWeLab provides a network of ISO 17025 and COFRAC accredited partner laboratories , specialized in stability tests, accelerated aging tests and physicochemical analyses .
Our experts support manufacturers, formulators and design offices in:

• The design and monitoring of accelerated stability protocols .
• interpretation of results and modeling of shelf lives .
• 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.