L’Oréal finds new method to evaluate efficacy of dispensing systems to avoid contamination

As the cosmetic industry increasingly focuses on developing preservative-free products, the packaging system plays a crucial role in protecting its content during use.

The study, published in the International Journal of Cosmetic Science​, developed an experimental test method to address three major issues relating to content protection, dose protection, and to afford a possible objective comparison between different systems.

The proposed protocol discriminates between different packaging systems and provides information on strong and weak features of certain types of packaging and their dispensing technology, prone to efficiently decrease either the dose contamination or to prevent contamination in reaching the contained product.

This means that this new method can contribute to an objective selection of a packaging system for protecting a cosmetic product with a low content of preservative or preservative free; particularly with a strict distinction between content protection and dose protection properties.

Testing​

In their tests, the team aimed at mimicking contact with non-sterile skin or fingers, and the dispensing system was put into contact with a pre-contaminated fabric by a standardized colonization of the common bacterium P. aeruginosa​.

When applied to three different types of packaging, results showed that a given device may offer poor dose protection properties, while still displaying excellent content protection properties.

The team conclude that only considering the dose protection properties to assess the suitability of a packaging system is therefore both misleading and misinforming.

Considering the long period during which cosmetic products are or may be used, the protection of their content appears the most important characteristics, according to the study.

Contamination issue​

In common with the European Food Industry, cosmetics manufacturers must ensure the microbiological safety of their products, knowing that these are often used on a daily basis for long periods of time.

As they are filled into various kinds of containers from which the content is dispensed to the consumer in small amount, on variable daily frequencies, cosmetic products can therefore be considered as potentially ‘unsafe’ with regard to repeated uses that may lead to microbial contamination.

Every cosmetics manufacturer therefore has a dual responsibility regarding the microbiological quality of its products, and guaranteeing the microbial stability and safety of cosmetic products is most often achieved using a combination of preservatives.

With interest of late being shown in the development of preservative-free or self-preserving cosmetics, due to the negative perception of preservatives by some consumers, the industry is looking for alternatives to the use of preservatives without compromise.

The role of the packaging system will become increasingly important in safeguarding the microbiological quality of a preservative-free or self-preserving cosmetic product.