Nails, More than Just Skin Extensions by Courage & Khazaka

17 November 2020

Apart from its aesthetical aspect, a healthy fingernail has important protection functions and helps to improve sensitivity and the grip of the fingers.

There is a variety of nail products on the market, from nail polish and –remover, aesthetic nail treatments, artificial nails up to food supplements. For daily exposure of hands & nails to a straining environment, also products for nail basic care are being used, claiming to harden, smooth, moisturize or whiten the nail. Many different brands are constantly developing new treatments and concepts for the nail, such as over-night nail care. Along with the increasing awareness of the consumers towards the efficacy of ingredients, the safety of products is also moving more into focus.

Measurement tools to study the nail’s properties are indispensable for formulating new nail care concepts, to document their efficacy and safety and to make the appropriate claims around them. They are also used in clinical research of nail diseases, such as onycholysis and others, as well as for skin diseases that involve nail changes, such as psoriasis.

A new system to assess in-vivo the biomechanical features of the nail is the Nail StrainStress Meter NM 100 which has been developed in close cooperation with the University of Pavia, Italy. With different applicators, measuring parameters such as structural strength of the nail (cohesion of the nail matrix), hardness, firmness, thickness and flexibility/elasticity of the distal edge before and after applying a product or treatment on the nail, can precisely be evaluated by measuring the resistance against a compressive/bending force applied. The result is a curve in a force deflection diagram with its slope as a parameter.



Other nail parameters:

For measurements of nail colour and gloss around nail polish the Colorimeter and the Glossymeter are available.

Surprisingly, in general the evaporation rate from the nails (TransOnychial Water Loss – TOWL) is much higher than on the skin. This indicates that nails play an important role in the complete body’s metabolism. The Tewameter® TM Nano with its ultra-small open chamber has especially been developed to perform exact evaporation measurements on small or difficult to reach skin sites such as nails.


Optical measurements:

Cameras like the Visioscan® VC 20plus help to analyze the nail topography. Additionally, with the special adhesive tape (Corneofix®), the quality of the nail can be assessed. When mounted on the Visioscan® camera, number, size and thickness of flakes sticking to the tape can be evaluated.



Altogether a number of claims for the nails can be objectively measured: e.g. hardening, restructuring, strengthening and re-densifying, as well as colour, gloss or permeability of nail polish and safety related claims.

And why not try to test whether my anti-ageing hand cream does not also improve the condition of my fingernails? There are no limits to new claims created around nail care that can be proven with these new innovative methods that make a whole new world of claims possible.


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