Structural parameters involved in the permeation of propranolol HCl by iontophoresis and enhancers

The purpose of this work was to study the effect of iontophoretic transport of Propranolol hydrochloride on the lipidic organization of the stratum co rneum pretreated under passive or iontophoretic conditions by two model pen etration enhancers, sodium lauryl sulfate and hexadecyl trimethylammonium b romide. Characterization of human stratum corneum was performed by X-ray di ffraction, attenuated total reflectance-Fourier transform infrared (ATR-FTI R) spectroscopy and differential scanning calorimetry (DSC). The structural properties were compared with the iontophoretic permeability of propranolo l hydrochloride on human stratum corneum. The iontophoretic fluxes of propr anolol hydrochloride were effectively increased by two-fold in stratum corn eum pretreated with sodium lauryl sulfate. In contrast, they were halved in stratum corneum pretreated with hexadecyl trimethylammonium bromide. These results could be related to changes in the electrical and structural prope rties of the stratum corneum after incorporation of these enhancers. (C) 19 99 Elsevier Science B.V. All rights reserved.