Predicting absorption of fragrance Chemicals through human skin

In the endeavor to identify a mathematical model predictive of the mostly unexplored skin penetration of fragrance chemicals, the Potts-Guy equation was tested here by correlating the published, measured Kp for 20 such compounds with predicted Kp values. The data, covering a broad range of structures, are well described by that model (r 2 = 0.86, p < 0.001). Also, calculated octanol-water partition coefficients, an alternative in case of missing measured values, appear well founded when analyzed statistically: comparison of 33 measured partition values with the calculated log Ps show near-perfect correlation for the intermediate lipophilicity range typical of fragrance hemicals (0.5 < log P • 3.5; r 2 = 0.97, p • 0.001). The Potts-Guy relation thereby recommends itself as a simple and reliable method for the quantitative evaluation of human skin absorption potential of small-molecular-weight nonelectrolytes, and of fragrance chemicals, in particular where such data are largely missing.