Richard Guy and his collaborators: 'crackling' the skin code.

This paper aims to summarize the contributions of Richard Guy and collaborators to the skin field. Major contributions have been areas such as the modelling of skin absorption, use of spectroscopic techniques (Fourier transform infrared spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy and impedance spectroscopy) to characterize the skin barrier and the effects of enhancing techniques on the membrane, dermatopharmacokinetics and assessment of topical bio-availability, iontophoresis and reverse iontophoresis, and use of imaging techniques to elucidate pathways of penetration and the skin disposition of nanoparticles. The field of topical and transdermal drug delivery has benefitted incalculably from the extensive work of Guy and his group: their findings about mechanisms of drug delivery and permeation enhancement, and the development of methodologies which are now accepted as gold standards by skin scientists.