Standardization of skin cleansing <i>in vivo</i>: part I. Development of an Automated Cleansing Device (ACiD)

TLDR

There are no legally binding requirements for cosmetic product testing, resulting in manufacturer‑specific methods and opaque information on skin cleansing products. The study aims to develop a standardized in vivo test for cleansing efficacy and barrier impairment, particularly for occupational hand washing at short intervals. An Automated Cleansing Device (ACiD) was designed and evaluated, comparing smooth washing surfaces such as goat hair, felt, and felt with nitrile caps for skin compatibility. ACiD delivers a fully automated, standardized skin washing procedure, and felt with nitrile provides homogeneous cleansing without detectable irritation, allowing objective evaluation of industrial skin cleansers' efficacy and safety.

Abstract

Background To date, there are no legally binding requirements concerning product testing in cosmetics. This leads to various manufacturer‐specific test methods and absent transparent information on skin cleansing products. A standardized in vivo test procedure for assessment of cleansing efficacy and corresponding barrier impairment by the cleaning process is needed, especially in the occupational context where repeated hand washing procedures may be performed at short intervals. Methods For the standardization of the cleansing procedure, an Automated Cleansing Device ( AC iD) was designed and evaluated. Different smooth washing surfaces of the equipment for AC iD (incl. goat hair, felt, felt covered with nitrile caps) were evaluated regarding their skin compatibility. Results AC iD allows an automated, fully standardized skin washing procedure. Felt covered with nitrile as washing surface of the rotating washing units leads to a homogenous cleansing result and does not cause detectable skin irritation, neither clinically nor as assessed by skin bioengineering methods (transepidermal water loss, chromametry). Conclusions Automated Cleansing Device may be useful for standardized evaluation of the cleansing effectiveness and parallel assessment of the corresponding irritancy potential of industrial skin cleansers. This will allow objectifying efficacy and safety of industrial skin cleansers, thus enabling market transparency and facilitating rational choice of products.