Laboratory stability testing: ensuring the quality and durability of your products

Stability testing is essential in sectors such as the pharmaceutical, cosmetic, food and medical device industries, where quality and effectiveness must be guaranteed throughout the product's lifespan.

Stability testing is governed by specific standards and guidelines, such as ISO 11930 for the microbiological stability of cosmetics, or the regulatory requirements in force for foodstuffs and dietary supplements. These requirements allow manufacturers to justify a product's shelf life, define its best before date (BEST BEFORE) or expiry date, and ensure its compatibility with its packaging.

In the laboratory, several types of stability tests are carried out depending on the objectives of the study:

• Accelerated stability test : This test simulates premature aging of the product by subjecting it to extreme temperature and humidity conditions. It allows for the identification of possible degradation and the estimation of the product's lifespan in a short period of time.
• Long-term stability test : this is an evaluation under normal storage conditions, allowing the measurement of product variations over a defined period (6, 12, 24 months or more) in order to confirm its conformity and quality over time.
• Packaging compatibility : This test analyzes the interaction between the product and its packaging. It allows for the detection of possible migrations of undesirable substances, alterations in the formulation, or changes in the packaging material that could affect the product's quality.
• Microbiological stability testing : This analysis aims to monitor the evolution of microbial load over time and to evaluate the effectiveness of preservatives. It is particularly important for products sensitive to contamination, such as cosmetics and pharmaceutical solutions.
• Photostability tests : These tests measure the impact of light exposure, particularly UV light, on product stability. They are essential for sensitive formulations, such as photosensitive drugs, cosmetics containing fragile active ingredients, or food products prone to oxidation.

All of these studies help to optimize product formulation, adapt recommended storage conditions and meet the requirements of regulatory authorities before marketing.