Penetration of compounds through human stratum corneum as studied by Fourier transform infrared photoacoustic spectroscopy.
The penetration of the lipophilic model permeant, 1-cyanodecane, into isolated human stratum corneum (SC) was followed nondestructively by step-scan Fourier transform infrared (FTIR) photoacoustic spectroscopy (PAS) with phase modulation technique. The uptake of the compound in the SC was quantified by monitoring the alterations in the spectra in the course of the penetration using multivariate analysis. Step-scan technique in conjunction with phase modulation offers the possibility for controllable depth profiling (sampling depth up to 30 microm) during the penetration process. Based on Fick's second law and assuming a virtually layered structure of the membrane, depth-dependent diffusion coefficients were derived by numerical fitting of the spectroscopic data. For 1-cyanodecane, the diffusion coefficient in the inner region of the SC is 1.6-fold that measured in the outer region.
Hanh
B D
BD
School of Pharmacy, Institute of Pharmaceutics and Biopharmaceutics, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany.
Neubert
R H
RH
Wartewig
S
S
Lasch
J
J
D004058:Diffusion; D004817:Epidermis / Q000378:metabolism*; D006801:Humans; D017550:Spectroscopy, Fourier Transform Infrared