Nail plate hydration

Nail plate hydration refers to the water content within the nail plate, a structural composite primarily formed of hard keratins cross-linked by disulfide bonds[3][4]. The typical water content of a healthy nail plate is about 18% but can rise above 30% when exposed to moisture, at which point the nail becomes soft and opaque, or fall below 18%, causing brittleness[4]. Hydration greatly influences the mechanical (flexibility, hardness) and biophysical (permeability, electrical resistance) properties of the nail[1][2][3][4]. In drug delivery, especially for transungual (through the nail) therapies, increasing nail hydration enlarges the porous keratin network, reduces electrical resistance, and enhances drug penetration[1][2][3]. Although hydration is essential for nail health and topical drug efficacy, it does not act as a molecular target, receptor, or enzyme, but is a critical biophysical condition for both research and clinical applications.

Other names

Hydration of nail platenail hydrationwater content of nail plate

Hydration increases nail permeability for passive and iontophoretic drug delivery by expanding the keratin network and decreasing electrical resistance[1][2][3]