Effect of Several Electrolyzed Waters on the Skin Permeation of Lidocaine, Benzoic Acid, and Isosorbide Mononitrate

Abstract

The effects of several electrolyzed waters were evaluated on the permeation of model base, acid and non-ionized compounds, lidocaine (LC), benzoic acid (BA), and isosorbide mononitrate (ISMN), respectively, through excised hairless rat skin. Strong alkaline-electrolyzed reducing water (ERW) enhanced and suppressed the skin permeation of LC and BA, respectively, and it also increased the skin permeation of ISMN, a non-ionized compound. On the contrary, strong acidic electrolyzed oxidizing water (EOW) enhanced BA permeation, whereas suppressing LC permeation. Only a marginal effect was observed on the skin permeation of ISMN by EOW. These marked enhancing effects of ERW on the skin permeation of LC and ISMN were explained by pH partition hypothesis as well as a decrease in skin impedance. The present results strongly support that electrolyzed waters, ERW and EOW, can be used as a new vehicle in topical pharmaceuticals or cosmetics to modify the skin permeation of drugs without severe skin damage.

Keywords:

• electrolyzed water
• alkaline reducing water
• acidic oxidizing water
• skin permeation
• penetration enhancement

ACKNOWLEDGMENTS

We gratefully acknowledge Dr. Shoji Kubota, Water Design Laboratory, for his frequent advise on the execution of this research. We also thank Dr. Masahiro Okajima, A. I. System Products, for the S-100, and Ms. Megumi Yoshida (nee Yonaga) for her assistance in the skin-permeation study.