INTRODUCTION
The vehicle into which a topical medication is placed can either improve or damage the skin barrier. Many topical medications are formulated with simple vehicle designs and generous penetration enhancement to insure minimal vehicle effect and good efficacy. While this approach to topical medication development increases chances for successful statistically significant differentiation of active drug from vehicle in phase III pivotal efficacy studies required for regulatory approval, it does not translate into the best topical formulations for skin disease. This becomes apparent when the drug successfully achieves approval status, but possesses dryness, stinging, burning, and/or itching when prescribed by dermatologists. Even though the drug has proved efficacious, it still is a failed drug if not well tolerated by patients.
One of the most challenging dermatologic conditions for topical formulation is rosacea. Rosacea patients possess sensitive skin characterized by easy flushing/blushing due to vasomotor instability, a damaged skin barrier due to chronic inflammation, and heightened neurosensory awareness leading to noxious sensory stimuli following topical product application.1 These facial tendencies create problems for the formulator who must create an optimal drug delivery vehicle that is aesthetically pleasing and appropriate for the sensitive skin of rosacea. If the vehicle produces barrier damage, it will enhance the inflammation characteristic of papulopustular rosacea leading to worsening of the disease process.
This research examined an investigational topical 3% minocycline anhydrous gel; the new investigational topical gel contains 3% minocycline base formulated in a moisturizing vehicle containing hydrocarbon-based gelling agents that afford occlusive properties to the formulation. This formulation was tested for its ability to improve the epidermal barrier by examining skin transepidermal water loss (TEWL) and corneometry measurements before and after 4 weeks of once-daily application.
One of the most challenging dermatologic conditions for topical formulation is rosacea. Rosacea patients possess sensitive skin characterized by easy flushing/blushing due to vasomotor instability, a damaged skin barrier due to chronic inflammation, and heightened neurosensory awareness leading to noxious sensory stimuli following topical product application.1 These facial tendencies create problems for the formulator who must create an optimal drug delivery vehicle that is aesthetically pleasing and appropriate for the sensitive skin of rosacea. If the vehicle produces barrier damage, it will enhance the inflammation characteristic of papulopustular rosacea leading to worsening of the disease process.
This research examined an investigational topical 3% minocycline anhydrous gel; the new investigational topical gel contains 3% minocycline base formulated in a moisturizing vehicle containing hydrocarbon-based gelling agents that afford occlusive properties to the formulation. This formulation was tested for its ability to improve the epidermal barrier by examining skin transepidermal water loss (TEWL) and corneometry measurements before and after 4 weeks of once-daily application.
MATERIALS AND METHODS
31 male and female subjects 18+ years of age of all Fitzpatrick skin types and complexion types with moderate facial rosacea, defined as 15+ inflammatory facial lesions, were enrolled
