The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Howard I. Maibach - One of the best experts on this subject based on the ideXlab platform.
-
the correlation between Transepidermal Water Loss and percutaneous absorption
2015Co-Authors: Jacquelyn Levin, Howard I. MaibachAbstract:The extensive procedure required to measure percutaneous absorption versus Transepidermal Water Loss (TEWL) enhances the desire to find a correlation between the two measurements in order to more easily assess skin barrier function and should aid in the understanding and development of penetration enhancers. However, experiments investigating a quantitative and/or qualitative correlation between the two indicators have resulted in controversy. In a review by Levin and Maibach in 2005, nine studies investigating the correlation between TEWL and percutaneous absorption were reviewed. Of the nine studies reviewed, a majority demonstrated a significant quantitative correlation, and a few found no quantitative correlation. At that time it was thought that the correlation between TEWL and percutaneous absorption may not hold for in vitro experimentation models, extremely lipophilic compounds, or possibly experiments performed on animal skin. Since then, several studies have been published investigating the relationship between TEWL and percutaneous absorption using a very lipophilic compound, in vitro models, and animal skin, and all studies have demonstrated a significant quantitative correlation. This chapter serves as an updated review of some of the major studies investigating the correlation between TEWL and percutaneous absorption.
-
the correlation between Transepidermal Water Loss and percutaneous absorption an overview
Journal of Controlled Release, 2005Co-Authors: Jackie Levin, Howard I. MaibachAbstract:Independently, both Transepidermal Water Loss (TEWL) and percutaneous absorption measurements accurately gauge stratum corneum skin Water barrier integrity. Both TEWL and percutaneous absorption rates increase when the integrity of the SC barrier is compromised. Experiments to discern a quantitative and/or qualitative correlation between the two indicators have resulted in controversy. This paper reviews some major studies investigating this correlation.
-
in vitro measurement of Transepidermal Water Loss a rapid alternative to tritiated Water permeation for assessing skin barrier functions
International Journal of Pharmaceutics, 1998Co-Authors: Sunita Patil, Avinash Nangia, Bret Berner, Anders Boman, Howard I. MaibachAbstract:Abstract Transepidermal Water Loss (TEWL), as measured with an evaporimeter, was used as a rapid assessment of the integrity of the barrier properties of skin as part of in vitro skin permeation studies. For a variety of physical and chemical treatments (i.e. solvent extraction, surfactants, mechanical abrasion and bases) TEWL correlated strongly with tritiated Water permeation at short times. In contrast to the tedious process of measuring permeation of a finite dose of tritiated Water, TEWL is a rapid, convenient measurement, and it provides a clear indication of the time dependence of barrier integrity.
-
Time-dependent variations of the skin barrier function in humans: Transepidermal Water Loss, stratum corneum hydration, skin surface pH, and skin temperature
Journal of Investigative Dermatology, 1998Co-Authors: Gil Yosipovitch, G L Xiong, Erhard Haus, Isaac Ashkenazi, Linda Sackett-lundeen, Howard I. MaibachAbstract:Although circadian rhythms have been described for many human functions, there are minimal data on circadian rhythms related to skin physiology. This study investigated the circadian rhythmicity of skin variables related to skin barrier function in humans. We measured Transepidermal Water Loss, stratum corneum moisture, skin surface pH, and skin temperature in 16 healthy volunteers (nine men and seven women, aged 23-53 y). Subjects were sampled every 2 h in two sessions over a 24 h span. Twelve samples were obtained for each variable in the following sites: forehead, forearm, upper back, and shin. We used cosinor analysis and ANOVA to validate observed differences. Time-dependent rhythms were detected in most skin variables except in stratum corneum hydration. We found a statistically significant circadian rhythmicity characterized by cosinor analysis in Transepidermal Water Loss, skin surface pH, and skin temperature on the forearm, forehead, and shin. Peak-trough differences occurred in all locations. The values of the same variables measured at different sites correlated positively, whereas the values of the different variables did not. These results suggest that skin permeability is higher in the evening and night than in the morning. These data may be clinically relevant in several aspects applied to skin physiology and topical drug application.
-
Standardized trauma (tape stripping) in human vulvar and forearm skin. Effects on Transepidermal Water Loss, capacitance and pH.
Acta Dermato-venereologica, 1991Co-Authors: D. Wilhelm, Peter Elsner, Howard I. MaibachAbstract:Mechanical trauma to genital skin may favor the transmission of sexually transmitted diseases. To study differences between vulvar and forearm skin in epidermal repair after standardized trauma, Transepidermal Water Loss, capacitance and pH of forearm and vulvar skin in 10 healthy premenopausal women were monitored for 7 days after a standardized trauma induced by tape stripping to glistening. Vulvar and forearm skin showed similar responses immediately after tape stripping: a sudden increase in Transepidermal Water Loss and capacitance
Gil Yosipovitch - One of the best experts on this subject based on the ideXlab platform.
-
Effect of radiant warmer on Transepidermal Water Loss (TEWL) and skin hydration in preterm infants.
Journal of Perinatology, 2004Co-Authors: A. Maayan-Metzger, Elior Hadad, Gil Yosipovitch, Lea SirotaAbstract:Effect of Radiant Warmer on Transepidermal Water Loss (TEWL) and Skin Hydration in Preterm Infants
-
Effect of Radiant Warmer on Transepidermal Water Loss (TEWL) and Skin Hydration in Preterm Infants
Journal of Perinatology, 2004Co-Authors: A. Maayan-Metzger, Elior Hadad, Gil Yosipovitch, Lea SirotaAbstract:OBJECTIVE: To evaluate the effect of radiant warmers on skin barrier function in preterm infants. METHODOLOGY: Transepidermal Water Loss (TEWL) and stratum corneum hydration were measured in 30 preterm infants (birth weight 825 to 2220 g) in seven body areas: forehead, upper back, cubital fossa, palms, soles, abdomen, and inguinal region. Measurements were performed under radiant warmer and incubator conditions. Each patient served as his/her control. RESULTS: TEWL was significantly higher in the radiant warmer compared to the incubator condition in only two areas: forehead and back. The overall mean difference in percentage TEWL between the conditions was 15%. Stratum corneum hydration was not affected by the radiant warmer. CONCLUSIONS: The use of radiant warmers does not significantly decrease barrier function in the preterm infant.
-
Time-dependent variations of the skin barrier function in humans: Transepidermal Water Loss, stratum corneum hydration, skin surface pH, and skin temperature
Journal of Investigative Dermatology, 1998Co-Authors: Gil Yosipovitch, G L Xiong, Erhard Haus, Isaac Ashkenazi, Linda Sackett-lundeen, Howard I. MaibachAbstract:Although circadian rhythms have been described for many human functions, there are minimal data on circadian rhythms related to skin physiology. This study investigated the circadian rhythmicity of skin variables related to skin barrier function in humans. We measured Transepidermal Water Loss, stratum corneum moisture, skin surface pH, and skin temperature in 16 healthy volunteers (nine men and seven women, aged 23-53 y). Subjects were sampled every 2 h in two sessions over a 24 h span. Twelve samples were obtained for each variable in the following sites: forehead, forearm, upper back, and shin. We used cosinor analysis and ANOVA to validate observed differences. Time-dependent rhythms were detected in most skin variables except in stratum corneum hydration. We found a statistically significant circadian rhythmicity characterized by cosinor analysis in Transepidermal Water Loss, skin surface pH, and skin temperature on the forearm, forehead, and shin. Peak-trough differences occurred in all locations. The values of the same variables measured at different sites correlated positively, whereas the values of the different variables did not. These results suggest that skin permeability is higher in the evening and night than in the morning. These data may be clinically relevant in several aspects applied to skin physiology and topical drug application.
Klaus-p. Wilhelm - One of the best experts on this subject based on the ideXlab platform.
-
Skin Aging: Effect on Transepidermal Water Loss, Stratum Corneum Hydration, Skin Surface pH, and Casual Sebum Content
Archives of Dermatology, 1991Co-Authors: Klaus-p. Wilhelm, Anastasia B Cua, Howard I. MaibachAbstract:* This study investigates the effect of cutaneous aging on Transepidermal Water Loss, stratum corneum hydration (capacitance), skin surface pH, and casual sebum content. Because the physiologic condition of skin varies considerably with anatomic region and skin aging might demonstrate regional variability, all factors were studied on 11 anatomic locations in 14 young adult (seven female and seven male subjects; 26.7 {+/-} 2.8 years [mean {+/-} SD]) and 15 aged human volunteers (seven female and seven male subjects; 70.5 {+/-} 13.8 years). Significant anatomic variability was noted for all factors in both age groups. However, no significant differences between the two groups were noted for sebum, capacitance, and pH on most anatomic regions. Transepidermal Water Loss, however, was significantly lower in the aged population on all anatomic regions tested, except for the postauricular region and the palm. Comparing male and female volunteers, none of the four factors showed significant differences. Of all measured factors, only Transepidermal Water Loss showed significant age-related differences on most anatomic regions studied. The additionally observed differences between the age groups on the ankle for pH and sebum might be related to the stasis frequently observed on the lower limbs in aged individuals.
Lea Sirota - One of the best experts on this subject based on the ideXlab platform.
-
Effect of radiant warmer on Transepidermal Water Loss (TEWL) and skin hydration in preterm infants.
Journal of Perinatology, 2004Co-Authors: A. Maayan-Metzger, Elior Hadad, Gil Yosipovitch, Lea SirotaAbstract:Effect of Radiant Warmer on Transepidermal Water Loss (TEWL) and Skin Hydration in Preterm Infants
-
Effect of Radiant Warmer on Transepidermal Water Loss (TEWL) and Skin Hydration in Preterm Infants
Journal of Perinatology, 2004Co-Authors: A. Maayan-Metzger, Elior Hadad, Gil Yosipovitch, Lea SirotaAbstract:OBJECTIVE: To evaluate the effect of radiant warmers on skin barrier function in preterm infants. METHODOLOGY: Transepidermal Water Loss (TEWL) and stratum corneum hydration were measured in 30 preterm infants (birth weight 825 to 2220 g) in seven body areas: forehead, upper back, cubital fossa, palms, soles, abdomen, and inguinal region. Measurements were performed under radiant warmer and incubator conditions. Each patient served as his/her control. RESULTS: TEWL was significantly higher in the radiant warmer compared to the incubator condition in only two areas: forehead and back. The overall mean difference in percentage TEWL between the conditions was 15%. Stratum corneum hydration was not affected by the radiant warmer. CONCLUSIONS: The use of radiant warmers does not significantly decrease barrier function in the preterm infant.
Gregor B E Jemec - One of the best experts on this subject based on the ideXlab platform.
-
instrumental assessment of atopic eczema validation of Transepidermal Water Loss stratum corneum hydration erythema scaling and edema
Journal of The American Academy of Dermatology, 2006Co-Authors: Elisabeth A Holm, Hans Christian Wulf, Lars Thomassen, Gregor B E JemecAbstract:Background Quantification of skin diseases can be carried out in many ways. Clinical scores are widely used in atopic eczema (AE), and noninvasive instruments are a relevant supplement. Objective Our purpose was to validate 5 noninvasive instruments in quantification of AE severity. Methods In all, 101 patients with AE and 30 control subjects were assessed twice in a clinical cross-sectional examination. Assessment of Transepidermal Water Loss, stratum corneum hydration, erythema, scaling, and subepidermal edema was assessed on 3 predetermined skin sites. Results The methods discriminated among various severity degrees and correlated significantly with objective assessment of disease severity. High correlations were found among instruments assessing acute symptoms of AE. Threshold values for Transepidermal Water Loss and capacitance were found. Limitations No gold standard exists for severity assessment of atopic eczema. Therefore, the methods used cannot be validated in relation to such a standard. Furthermore, atopic eczema is a generalized disease and the methods used assess target lesions. By assessing target lesions, information about the disease is reduced. Conclusion Noninvasive instruments are valuable in quantification of disease severity in a mixed group of patients with active AE. Assessment with ultrasound has contributed new information about the pathophysiology in AE.
