The development of a product, its safety and stability require many preliminary tests and a careful examination of the biological environment on which the product will be used.
Prior to placing a new cosmetic product on the market, you, as the responsible person, must ensure consumers safety. Therefore it is essential that your product is safe for them under normal or reasonably foreseeable conditions of use.
Cosmetic evaluation of the product consists in the safety assessment for human health, assessment of product toxicity and possibly efficacy testing to prove your claims.
The safety assessment is conducted by an expert (doctor, toxicologist or equivalent qualified person authorised by the regulation). Don’t forget that ANSM (formerly AFFSAPS) may at any time order a recall of a product likely to be dangerous to human health, hence the importance of this evaluation phase. We distinguish three categories of tests.
The challenge Test, a key parameter
Challenge testing is the assessment of the preservative efficacy, it is a microbiological evaluation of a product’s ability to prevent the growth of microorganisms over a relatively long period of time (Over 28 days). The test consists in challenging a non contaminated product with prescribed inoculums of suitable microorganisms and storing the inoculated product at a prescribed temperature. Using serial dilutions and plate counts, the number of organisms surviving in the test products is determined at specified interval of times.
Stability Test: Study of the durability of the product (Best-before date / PAO)
The challenge test is not enough to specify the durability of the product. Stability testing consists in accelerated aging (typically 40°C) and assessment of product integrity with regard to several relevant criteria, based on the product: microbiological criteria, but also physical or chemical ones (pH, viscosity…) as well as organoleptic ones (odor, color…). Generally, stability tests can be conducted in real time or under accelerated conditions and should address the stability of a product under appropriate conditions of storage, transport and use.
Skin irritation test – Patch Test
The patch test is the most common test in dermatology contact and allows the study of skin tolerance. It consists in a single application of the product, normally for 24 or 48 hours on 10 volunteers under occlusive or semi-occlusive patch on the arm or the back. Then we can evaluate the outbreak of any skin reactions at patch removal (under medical or dermatological supervision).
Eye irritation test
It is the study of ocular tolerance that is normally performed by in-vitro techniques (alternative methods to animal testing) such as HET-CAM.
It is the study of tolerance to repeated applications under the normal conditions of use of the product (2 to 3 weeks, 10 to 20 volunteers, sometimes tested on the elbow).
It is the study of the sensitizing potential of the product which includes an induction phase (regular applications for 3 weeks), a resting phase (2 weeks) and a triggering phase (an additional application) generally on 50 or 100 volunteers.
It is the study of the phototoxic potential of the product. It consists in treating cells in vitro and to compare the responses obtained after being exposed to UVA or not.
These tests are usually performed if you want to highlight the properties of your product and its efficacy. Indeed, the European regulation requires cosmetic claims to be proven, such as:
Moisturizing, Anti-aging , Firming/ Tensor/ Toning, Slimming…