%K Human skin Penetration and permeation kinetics, Stratum corneum, Mathematical models, Franz cell diffusion, Tape stripping, Raman microspectroscopy %J Trends in Analytical Chemistry %I Elsevier %L discovery10150140 %V 156 %A Majella Lane %A Gerwin Puppels %A Hugh Byrne %A Dominique Lunter %A Stephan Bielfeldt %A Franck Bonnier %A Igor Chourpa %A Yuri Dancik %A Emilie Munnier %A Ali Tfayli %A Eric Ziemons %X The study of human skin represents an important area of research and development in dermatology, toxicology, pharmacology and cosmetology, in order to assess the effects of exogenous agents, their interaction, their absorption mechanism, and/or their toxicity towards the different cutaneous structures. The processes can be parameterised by mathematical models of diffusion, of varying degrees of complexity, and are commonly measured by Franz cell diffusion, in vitro, and tape stripping, in vitro or in vivo, techniques which are recognised by regulatory bodies for commercialisation of dermally applied products. These techniques do not directly provide chemically specific measurement of the penetration and/or permeation of formulations in situ, however. Raman microspectroscopy provides a non-destructive, non-invasive and chemically specific methodology for in vitro, and in vivo investigations, in-situ, and can provide a powerful alternative to the current gold standard methods approved by regulatory bodies. This review provides an analysis of the current state of art of the field of monitoring dermal penetration and permeation kinetics of topical products, in vitro and in vivo, as well as the regulatory requirements of international guidelines governing them. It furthermore outlines developments in the analysis of skin using Raman microspectroscopy, towards the most recent demonstrations of quantitative monitoring of the penetration and permeation kinetics of topical products in situ, for in vitro and in vivo applications, before discussing the challenges and future perspectives of the field. %O © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). %T Monitoring Dermal Penetration and Permeation Kinetics of Topical Products; the Role of Raman Microspectroscopy %D 2022