title: A new technique associated with the evaporimetry method for evaluating occlusion.
abstract: The stratum corneum is the outermost layer of the skin. It constitutes a permeability barrier that keeps micro-organisms and toxic agents from entering the skin, while retaining water and electrolytes. In order to preserve its colour and elasticity, the skin needs lipids and water. Certain occlusive products in contact with the skin diminish its natural transepidermal water loss (TEWL), and the occlusion potential of such products can be evaluated with the aid of evaporimetry. The purpose of this work was to increase the sensitivity of the method by associating the well-established methodology for measuring TEWL with a technique for removing occlusive products from the skin. The present study was designed to evaluate the procedure of measuring TEWL evaporimetrically (the traditional method) in comparison with our new method, which employs the same evaporimetric measurement combined with a removal technique that uses cotton to remove the physical barrier that occlusive products form on the skin. The product used in this study was solid petrolatum (petroleum jelly), which possesses well-known occlusive properties. The TEWL measurements were made over a pre-defined period of time, on different skin sites, and were systematically compared with the results generated by an untreated control site. The TEWL was first determined by the classic method (without product removal), then the product was removed and new readings were taken. Our results show that the classic technique was unable to show a statistical distinction between the occlusion capability of solid petrolatum and the untreated control site, whereas this same method used in association with product removal provided a statistically significant difference between the TEWL measured on the occluded and control sites. Therefore, our removal technique associated with the traditional method for measuring TEWL proved capable of increasing the response sensitivity of evaporimetry with occlusive products.
authors.affiliation: Natura Inovação e Tecnologia de Produtos Ltda., Rodovia Anhanguera, SP, Brazil. julianamarques@natura.net
authors.forename: J P P
authors.initials: JP
authors.lastname: Marques
authors.forename: D S B
authors.initials: DS
authors.lastname: Basso
authors.forename: A S
authors.initials: AS
authors.lastname: Nunes