Molecular Adhesion and Transepidermal Water Loss of Liquid Skin Protectants

Introduction: Skin protectants with superior breathability, used to guard susceptible epidermal regions, are important for the proper management of intact or damaged skin.^1,2,3 Solvent based skin protectants are the standard of care; however, a novel class of solvent-free skin protectants, i.e cyanoacrylates have been developed that work via the formation of bonding interactions to the stratum corneum.^4,5 The purpose of this study was to determine the breathability and microscopic nature of the attachment of barriers to skin for these two types of protectants.  

Methods: The skin protectants used in this study were a cyanoacrylate monomer blend^* and a solvent based acrylate polymer⁺. Sections of pigskin were coated with the skin protectants and photographed, after cross sectioning, under varying microscopy conditions. For breathability analysis, ten participants were selected.  Portions of their volar forearm were coated with the protectants. Transepidermal Water Loss (TEWL) measurements were taken to establish a baseline TEWL value, and TEWL was measured one and two hours post-application. 

Results: Microscopy images revealed the cyanoacrylate barrier was more intimately bound directly to the pig skin, and was nearly four times thicker than a typical application of the acrylate film, when both products were applied per their instructions for use. Breathability comparisons of both products indicate significant (p<0.05) drops in TEWL after one hour. After two hours, the cyanoacrylate significantly increased (p=0.04) in TEWL compared to the acrylate, and no longer varied significantly from the baseline. The acrylate product continued to remain lower in TEWL values, remaining significantly different from the baseline.

Conclusion: The cyanoacrylate bound more intimately to skin, produced a thicker layer, and had a higher TEWL values as a measurement of breathability. The reason may be due to molecular level differences between the materials used in the two barriers. Additional studies are warranted.