Influence of Ethanol as a Preservative in Topical Formulation on the Dermal Penetration Efficacy of Active Compounds in Healthy and Barrier-Disrupted Skin.

(1) Background: Ethanol is a multifunctional excipient often used as a preservative in topical formulations. Due to its known ability to impair skin barrier function, this study investigated the effect of ethanol (EtOH) as a preservative in creams on the dermal penetration of active compounds. (2) Methods: A hydrophilic and a lipophilic fluorescent dye were used as active ingredient surrogates that were incorporated into creams with and without ethanol.