Ranking of surfactant skin irritancy in vivo in man using the plastic occlusion stress test (POST)

Abstract

Irritant effects and disturbance of water-holding capacity induced by surfactants were investigated using the plastic occlusion stress test (POST) technique. 4 surfactants (sodium lauryl sulphate (SLS), sorbitan monolaurate, cocoamidopropyl betaine and benzalkonium chloride) and an amphoteric/nonionic (A/N) mix were investigated. 1 x daily for 3 days, test surfactants were applied to marked sites (open) on the volar forearm. After 24 h occlusion with a plastic chamber on the 4th day, skin surface water loss (SSWL) (g/m2h) was recorded continuously for 25 min with an evaporimeter. The differences between the surfactants were statistically significant (Friedman's test p less than 0.01). SLS and the A/N mix revealed significant differences compared to the other compounds (p less than 0.05), both in decay constants and in values recorded at the beginning and at the end of the decay curve. The study suggests a mechanism for the high irritant potential of sodium lauryl sulphate compared to other surfactants: sorbitan monolaurate and benzalkonium chloride seem to influence (at the concentrations tested) to a lesser extent the water-holding capacity of the stratum corneum. The clinical and biological relevance of these observations requires long-term clinical correlations with final product use tests.

Assessing the in vivo impact of a gel sanitizer on the epidermal barrier dynamics

“…A fim de melhorar a precisão das medições da PTEA, outras abordagens dinâmicas têm sido sugeridas. Os testes de acumulação de humidade (MAT) [9] , de sorção/dessorção [10] e de oclusão plástica (POST) [11] são exemplos relevantes que servem como base conceptual para o modelo aqui aplicado, permitindo uma descrição quantitativa mais precisa do balanço de massa de água cutânea ao longo do tempo [12][13][14] . O presente estudo avalia o impacto da utilização de um gel desinfetante de base alcoólica sobre a função de 'barreira' epidérmica, usando uma abordagem de modelação cinética das curvas de dessorção da PTEA após um POST.…”

“…In order to improve the precision of TEWL measurements, other dynamical approaches have been suggested. The moisture accumulation test (MAT) [9] , the sorption/desorption test [10] , and the plastic occlusion stress test (POST) [11] are relevant examples serving as the conceptual basis for the compartmental model here applied, allowing a more accurate quantitative description of the cutaneous water mass balance over time [12][13][14] . This study evaluates the impact of the use of an alcoholbased gel sanitizer on the epidermal 'barrier' function, using a kinetic approach of TEWL desorption curves following a POST test.…”

A simple method for oral mucosal irritation test by intraoral instillation in rats

“…SDS is also known to cause skin dermatitis (Berardesca et al, 1990) and oral mucosal irritation (Rantanen et al, 2002). The concentration of SDS in dentifrices usually ranges from 0.5% to 2.0% (Barkvoll et al, 1989), and it has been demonstrated that contacting of the dentifrice containing 1.5% SDS provokes desquamation of the oral mucosa in human (Herlofson and Barkvoll, 1993).…”

Assessing the impact of the regular use (4 weeks) of an alcohol-based hand sanitizer on TEWL and epidermal hydration

“…Portanto, uma pele saudável tende a possuir valores de PTEA mais baixos e, portanto, uma grande quantidade de água no estrato córneo [7] . A sensibilidade desta variável é maior quando se usam testes de provocação, incluindo o teste de oclusão plástica (POST) comumente usado [8][9][10] . Este estudo tem como objetivo avaliar o impacto do uso regular de quatro semanas de duração de um gel desinfetante à base de álcool na hidratação cutânea e na função epidérmica 'barreira' in vivo, usando um modelo cinético já estabelecido de curvas de dessorção de PTEA na sequência de um teste POST.…”

“…Healthy skin tends to possess lower TEWL values and therefore, a larger amount of water in the stratum corneum [7] . The sensitivity of this variable is increased when employing provocation tests, including the commonly used plastic occlusion stress test (POST) [8][9][10] . This study aims to evaluate the impact of a four week-long regular use of an alcohol-based gel hand sanitizer on in vivo skin hydration and the epidermal 'barrier' function, using a previously established kinetic modelling of TEWL desorption curves following a POST test.…”