A simple dermal absorption model: Derivation and application

This paper deals with the derivation of a QSAR for the estimation of:

• the skin permeation coefficient from aqueous solutions in cm h⁻¹,

• the stratum corneum/water partition coefficient.

These QSARs enable the estimation of:

• the aqueous permeation coefficient in cm h⁻¹,

• the maximum dermal absorption in mg cm⁻² h⁻¹ from a saturated aqueous solution at steady state,

• the lag time in hours (h),

• the diffusivity of a substance in the stratum corneum in cm² h⁻¹

By using the independent variables:

• the log(octanol/water partition coefficient),

• the molecular weight,

• the water solubility.

The estimated maximum dermal absorption and the lag time were compared with some recent measured data of substances, which were not used for developing the QSARs. The estimates were generally in the same order of magnitude as the measured absorption and lag time. These QSARs are recommended for risk assessment of chemicals in the scope of the European REACH legislation.