Study of pH effect on the skin in Franz cell by impedance spectroscopy: an attempt to model incontinence effect on the skin.

Abstract: The human skin is the largest and most complex body organ but accessible and attractive for biomarker sampling and transdermal drug delivery. The two procedures are significantly impacted by several biophysical properties of the skin, especially the pH and stratum corneum (SC)hydration. The varying levels of pH on the skin surface usually impact the permeability barrier function of the SC, contributing to the onset of dermatological disorders such as incontinence-associated dermatitis (IAD). Consequently, this scholarly work provides a comprehensive in vitro investigation of the effect of pH on the skin including the effect of artificial urine. The pig skin membranes were used to conduct electrical impedance spectroscopy (EIS)experiments using a four-electrode Franz cell set-up. Artificial urine and buffered solution with varying pH gradients were utilized to induce reversible changes in effective membrane capacitance (Ceff) and membrane resistance (Rmem). The in vitro investigation revealed that exposure to urine changed the electrical impedance properties of the skin. Specifically, we found that the application of artificial urine to the skin reduced skin resistance. At the same time, we also find systematic changes in skin capacitance. Skin capacitance increased with increased pH. Hence the two skin impedance parameters showed a clear effect of artificial urine on the skin. These changes, i.e., the decrease of Rmem and increase of Ceff of skin membranes when they are exposed to artificial urine, can be interpreted as skin barrier deterioration The information provided herein is relevant in describing the detrimental effect of urine on the skin, which probably makes skin barrier more permeable.