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FOCUS #9: Evaluation of anti-ageing products of multi-tone panels by IEC Group

5 December 2023

Anti-ageing cosmetics are designed to reduce the effects of skin ageing and help fight the effects of the passage of time in a global way. For some people, an anti-ageing product must act on the surface, at the level of the microrelief, but also deeper in the epidermis and/or dermis.

It should be noted that the signs of ageing that appear on the surface reflect the changes taking place in the different layers of the skin.

In fact, cutaneous ageing reflects the deterioration of all the components of the skin, the epidermis, dermis, and hypodermis.

In the epidermis, the slowing down in cell renewal and the reduction in the production of lipids on the skin’s surface mean that the skin is likely to be dry and rough. The mature epidermis may also develop pigmentation spots caused by exposure to the sun.

In the dermis, collagen production declines and is associated with a decline in elastin, leading to disorganization of the skin’s connective tissue. With the structure of the dermis altered, wrinkles appear.  In addition, blood supply to the skin decreases, which means that the supply of nutrients and oxygen to the skin’s surface is less effective, which is why the rosy glow characteristic of young skin tends to fade.

In the hypodermis, the size and number of fat cells decrease, which has repercussions on volume loss, leading to the formation of deep wrinkles and hollowing of the cheeks.

All these processes lead to an overall thinning of the skin and a loss of support, resulting in sagging skin.

In order to assess the anti-ageing effect of a cosmetic product, it will be possible to follow the evolution of different parameters such as hydration, the skin barrier function, the restructuring of the microrelief, the radiance of the complexion, the reduction in fine lines, wrinkles and spots, the increase in cell renewal, the thickness of the dermis, the firmness/tonicity/elasticity, the volume of the cheekbones and the refining of the oval of the face.

To support the development of products or the justification of recommendations for anti-ageing parameters, IEC offers an In Use Test with, as a first option, a visual assessment by experts which may include a scoring of wrinkles all over the face and/or ptosis, using photographic scales (Skin Aging Atlas, R. Bazin), the appearance (surface, intensity) of spots (sun lentigos), the hydrated appearance, radiance, luminosity and evenness of the complexion. Tactile scoring can also be performed to assess the skin firmness, density, elasticity, suppleness and softness. These scoring are supplemented by self-assessments by the subjects and specific consumer studies.

The previous proposals can be objectified by instrumental methods to reinforce the claims, such as a moisturizing effect [CorneometerÒ  CM825- Courage & Khazaka], or a protective/repairing effect [TewameterÒ  TM300 and TMHex – Courage & Khazaka].

The restructuring effect of an anti-ageing product is expressed as an improvement in micro-relief by following changes in the micro-depression network [Sampling of the skin surface with cyanoacrylate], [Moisture MapÒ MM100 – Courage & Khazaka], texture parameters such as entropy, homogeneity, anisotropy index [VisioscanÒ  VC20+ Courage & Khazaka / C-CubeÒ  – Pixience].

Smoothing/anti-wrinkle effects by reducing fine lines/wrinkles using skin replica analysis and image processing [Quantilines, Quantirides – Station Monaderm] which can be associated with a direct in vivo, non-contact optical method such as fringe projection [DermatopÒ  or AEVAÒ – EOTECH]. The evolution of skin relief over the whole face, wrinkles and fine lines can be followed using photographs [ColorfaceÒ, QIMA Life Sciences – Newtone] and image analysis, which can also be used to extract roughness parameters and monitor the evolution of the smooth appearance of the skin.

Lightening / whitening / pigmented spot reduced / homogeneity claims are assessed by direct instrumental measurements [ChromameterÒ, SpectrophotometerÒ, MexameterÒ – Minolta, SIAScope – SiametricsTM] or via analysis of photographic images [Colorface, C-cube], hyperspectral imaging [SpetraCamÒ or SpectraFaceÒ – QIMA Life Sciences – Newtone) and specific software [FrameScan – Orion Concept].

Photo-induced pigmentation that is not visible but will appear with age can be detected using polarised monochrome UV imaging [Colorface], and parameters such as the surface area or density of lesions can be extracted and monitored over time.

The firming effect of a product, such as firmness and elasticity, can be assessed by deforming the skin under the effect of suction [CutometerÒ  – Courage & Khazaka] or torsion [TorquemeterÒ] or, inversely by air flow [DynaskinÒ  or SkinFlexÒ – Orion Concept].

Other methods can be used to assess the action of anti-ageing products, such as the plumping effect on the cheekbones and lower cheeks and the refining of the oval of the face [AEVA] or the effect on increasing cell renewal [DHA colouring], and the thickness of the dermis using 25 MHz ultrasound [Dermcup].

Ageing is a natural process for all skin types, but its signs can vary depending on the skin ethnicity.

While loss of volume is a sign of ageing common to all ethnic groups, for Caucasian skin, ageing primarily takes the form of fine lines and wrinkles, while in Asian skin ageing is characterized by diffuse pigmentation spots of the actinic lentigo type, and African skin displays pigmentation disorders (hypo- or hyper-pigmentation) covering a larger area of the face.

From its multiethnic panel due to the geographical distribution of its testing centers [Europe, Asia, Africa]: Caucasian [Bulgaria, France: Lyon & Saint-Etienne], Asian [Singapore, Japan, China, Korea], African [Cape Town, South-Africa] IEC Group propose global appraisal of anti-age performances.

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CONTACT

www.iecfrance.com

Jean-Robert Campos

jr.campos@iecfrance.com