Morse, Chase N; Hite, Collin C; Wamer, Nathan C; Gadient, Jennifer N; Baki, Gabriella; Prestwich, Erin G
description
Benzalkonium chloride (BZK), alkyldimethylbenzlamonium chloride, is a cationic surfactant<br>that is used as an antiseptic. BZK is classified as a quaternary ammonium compound com-<br>posed of molecules of several alkyl chains of differing lengths, that dictate its effectiveness<br>towards different microbes. As a result, BZK has become one of the most used preserva-<br>tives in antibacterial solutions. Despite its widespread use, it is not clear whether BZK pene-<br>trates human skin. To answer this question, BZK treated skin was analyzed using matrix<br>assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry imaging.<br>Solutions containing BZK and differing excipients, including citric acid, caprylyl glycol, and<br>vitamin E, were applied ex vivo to excised human skin using Franz diffusion cells. Treated<br>skin was embedded in gelatin and sectioned prior to MALDI-TOF imaging. BZK penetrates<br>through the epidermis and into the dermis, and the penetration depth was significantly<br>altered by pH and additives in tested solutions.
