Aminolaevulinic acid diffusion characteristics in ‘<i>in vitro</i>’ normal human skin and actinic keratosis: implications for topical photodynamic therapy

Abstract

Sizable variation in ALA concentration was a prominent feature of profiles through AK lesions, which may explain the variation of observed protoporphyrin IX production seen in the clinical implementation of AK PDT. That said, the results of this study show sufficient ALA penetration to a depth of 1.0 mm, which should be satisfactory for successful treatment of the majority of non-hyperkeratotic, hypertrophic AK using patch-based delivery methods.