The evaluation of skin friction using a frictional feel analyzer.
OBJECTIVE
Sensory evaluation is an important factor for cosmetic products. Several devices for the measurement of sensory properties have been developed in recent years. The objective here is to measure skin surface friction using these devices and examine the correlation with other physiological parameters in order to evaluate the potential of physical measurement of tactile sensation.


METHODS
A KES-SE Frictional Analyzer, a commercial device for measurement of surface frictional characteristics, was used in this study. An arm holder was added to this device for measurement on the human forearm. The frictional coefficient (MIU) and its mean deviation (MMD) were used as the parameter to indicate surface friction. The moisture content in the stratum corneum was measured with a Corneometer CM825, the transepidermal water loss with a Tewameter TM210, the viscoelastic properties of the skin with a Cutometer SEM575 and the skin surface pattern by observing the negative replica using silicon rubber.


RESULTS
The MIU was not influenced by load; however, it was increased due to water application on the skin. The relationship between MIU and the moisture content in the stratum comeum, between MMD and skin surface pattern and between MMD and viscosity of both normal human forearm skin and SDS (sodium dodecyl sulfate)-induced dry skin were confirmed by statistical analysis in a test on human subjects. There was also a correlation between either MIU or MMD and sensory evaluation in the morning after the application of moisturizing products.


CONCLUSIONS
Human skin surface friction was measured by using a KES-SE Frictional Analyzer. Judging from the correlation between either MIU or MMD and sensory evaluation, we considered this instrumental analysis to be useful for evaluating the tactile impression of human skin.
Egawa
Mariko
M
Shisedo Research Center (SHIN-YOKOHAMA), Yokohama, Japan. mariko.egawa@to.shiseido.co.jp
Oguri
Motoki
M
Hirao
Tetsuji
T
Takahashi
Motoji
M
Miyakawa
Michio
M
D001703:Biophysics / Q000295:instrumentation*; D003358:Cosmetics; D004548:Elasticity; D005069:Evaluation Studies as Topic; D005542:Forearm; D017276:Friction; D006801:Humans; D012879:Skin Physiological Phenomena; D014110:Touch / Q000502:physiology*; D014783:Viscosity; D014867:Water / Q000378:metabolism
D003358:Cosmetics; D014867:Water