MALDI-TOF imaging analysis of benzalkonium chloride penetration in ex vivo human skin

PLoS One. 2024 Feb 8;19(2):e0297992. doi: 10.1371/journal.pone.0297992. eCollection 2024.

Abstract

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

MeSH terms

  • Anti-Infective Agents, Local* / pharmacology
  • Benzalkonium Compounds* / pharmacology
  • Humans
  • Preservatives, Pharmaceutical
  • Quaternary Ammonium Compounds
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

  • Benzalkonium Compounds
  • Anti-Infective Agents, Local
  • Quaternary Ammonium Compounds
  • Preservatives, Pharmaceutical

Grants and funding

Rockline Industries The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.