Halobetasol Propionate Lotion, 0.05% Provides Superior Hydration Compared to Halobetasol Propionate Cream, 0.05% in a Double-Blinded Study of Occlusivity and Hydration

February 2017 | Volume 16 | Issue 2 | Original Article | 140 | Copyright © February 2017


Gary Grove PhD,a Charles Zerweck PhD,a Tim Houser MS,a Anthony Andrasfay BS,b Bob Gauthier MS,b Charles Holland PhD,b and Daniel Piacquadio MDb

acyberDERM inc., Broomall, PA bTherapeutics Incorporated, San Diego, CA

Abstract
BACKGROUND: This study measured skin hydration and occlusivity of two test products [halobetasol propionate lotion, 0.05% (HBP Lotion) and Ultravate® (halobetasol propionate) cream, 0.05% (HBP Cream)] at 2, 4, and 6 hours after application to skin test sites previously challenged by dry shaving, which was performed to compromise the integrity of the stratum corneum barrier. METHODS: Trans-epidermal water loss (TEWL), an indicator of skin barrier function, was measured using cyberDERM, inc. RG-1 evaporimeter. Skin hydration was evaluated using IBS SkiCon-200 conductance meter. Test products were applied bilaterally on dry-shaved sites on the volar forearm sites, according to a randomization scheme, with two test sites untreated to serve as “dry-shaved” controls. TEWL and conductance were measured at 2, 4, and 6 hours post-treatment. RESULTS: HBP Lotion displayed a significant increase in skin hydration at 2, 4, and 6 hours post-treatment compared to the baseline values and dry-shaved controls (each, P less than 0.001). However, HBP Cream produced statistically significant increased skin hydration only after 6 hours (P less than 0.05). HBP Lotion was significantly more effective than HBP Cream in increasing skin hydration at 2 and 4 hours post-treatment (each, P less than 0.001), and had a directional advantage (not statistically significant) at 6 hours. Neither test product had a significant occlusive effect as measured by TEWL at 2, 4, and 6 hours post-application. CONCLUSION: Both formulations of HBP (Lotion and Cream) contributed to skin moisturization, as measured by skin conductance. HBP Lotion produced a significantly more rapid onset and higher level of moisturization at 2 and 4 hours post-application compared to HBP Cream. The TEWL results indicate that neither HBP Lotion nor HBP Cream provided any significant occlusivity to the skin.

J Drugs Dermatol. 2017;16(2):140-144.

BACKGROUND

Skin, the largest organ of the human body, provides an outer exible, resilient, and elastic shell as a remarkable physical, chemical, and biological barrier to the environment. Most of the protective, waterproofing, and insulating properties of the skin are conferred by its tightly packed outer layer called stratum corneum (SC). The SC measures approximately 30-50 μm in depth, but can be as thick as 100-120 μm, depending on the anatomical region. SC consists of approximately 30-50 layers of terminally differentiated keratinocytes. The integrity and proper conditioning of the SC play an essential part in maintaining skin’s barrier function. Trans-epidermal water loss (TEWL) and skin hydration are two physical measures routinely used to evaluate skin’s integrity and its overall health.1-7 Quantitative instrumental methods to evaluate TEWL and skin hydration have been developed and are used to assess the efficacy of moisturizers to “repair” damaged skin (ie, improve barrier function). TEWL represents the free diffusion of water vapor through the SC,5,8 while skin conductance re ects SC water content.3,9 Impairment of skin barrier function translates to elevated TEWL values, and has been reported in pathological skin conditions such as atopic dermatitis and psoriasis. TEWL is increased by injuries that damage the uppermost layers of SC (eg, skin abrasion, tape stripping, extraction of lipids from the SC by organic solvents or detergents). In general, an increase in TEWL is paralleled or followed by a decrease in skin hydration. However, in various dermatological conditions the picture can be a bit more complicated, due to a number of factors, such as the presence of local in ammation, infection, or edema. One of the essential therapeutic principles of treating dermatological conditions is to normalize the skin’s level of hydration. A cornerstone of treating numerous pruritic dry skin conditions (eg, atopic or allergic dermatitis, prurigo nodularis, psoriasis, and ichthyosis) is to restore skin hydration through sustained topical application of moisturizers. A