Exaggerated Wash Test to Clinically Validate ‘Care Cleansing’ Mildness

Jul 1st, 2022

Nattaya Lourith and Mayuree Kanlayavattanakul, Mae Fah Luang University, Chiang Rai, Thailand; Thep Chalermchai, Mae Fah Luang University, Bangkok; Hidetaka Kato, Salisa Chokmou and Safina Lopwichan Pigeon Industries (Thailand) Co., Ltd., Chon Buri, Thailand; and Koki TakahashI, Taiyo Kagaku Co., Ltd., Mie, Japan

Cosmetics & Toiletries

To test such products under real-use conditions, an exaggerated cumulative clinical is proposed and demonstrated here in a study assessing the mildness of a care cleansing formula. In today's reality, cleansing products must be developed to overcome the potential adverse effects caused by frequent and repeated use.

Read the full feature in the July/August 2022 digital edition here. . .

The circumstances of COVID-19 have drastically shifted our lifestyles to a new normal. Cleansing products have become more critical to daily hygiene as we face the pandemic globally. With repetitive use, however, cleansers can damage the skin’s barrier function, as many surfactant-containing formulas are known to dehydrate the stratum corneum (SC).

As a result of this dryness, individuals having highly sensitive skin are more likely to experience frequent adverse effects.¹ Moderate to mildly sensitive skin conditions also could be exacerbated. Care cleansing products will therefore be a major focus for the skin care market in the future; in fact, products that are effective yet mild, e.g., sulfate-free or based on mild surfactants, are already at the forefront of consumer regimes.²

Accordingly, cleansing products must be developed to overcome the potential adverse effects caused by more frequent use.³ Cleansing products with moisturizing effects, for example, are in high demand.^{4, 5}

To test such products for their mildness and efficacy after repeated use, it is important to consider that traditional patch testing is not likely to demonstrate the cumulative effects of continuous daily washing to sanitize the skin.³ As such, an exaggerated cumulative clinical test is proposed, which is demonstrated here in a study assessing the mildness of a care cleansing test formula.

References

Bornkessel, A., Flach, M., Arens-Corell, M., Elsner, P. and Fluhr, J.W. (2005). Functional assessment of a washing emulsion for sensitive skin: Mild impairment of stratum corneum by hydration, pH, barrier function, lipid content, integrity and cohesion in a controlled washing test. Skin Res Technol (11) 53-60.
Zrebiec, B., Miller, A., ... Mangier, M., ET A. (2020). Hair, scalp and gentle cleansing: Mega mildness, water consciousness, germ killing, microbiome care and naturals. Cosm & Toil 135(6) 18-21.
Maibach, H. (2020). Cumulative irritation and moisturizing/cleansing rating? Cosm & Toil 135(6) 11.
Kanlayavattanakul, M., Rodchuea, C. and Lourith, N. (2012). Moisturizing effect of alcohol-based hand rub containing okra polysaccharide. Int J Cosmet Sci (34) 280-283.
Lourith, N., Pungprom, S. and Kanlayavattanakul, M. (2021). Formulation and efficacy evaluation of the safe and efficient moisturizing snow mushroom hand sanitizer. J Cosmet Dermatol (20) 554-560.