Multimodal microscopy toolkit for visualizing multicomponent topical drug formulations in humans

Our group has recently developed a method for characterizing distribution of a topical drug within skin using two-photon fluorescence lifetime imaging (FLIM) and phasor analysis. Here, we expand on this work by describing a multimodal approach for rapidly visualizing multiple components in tissue using FLIM and coherent Raman imaging (CRI). By employing a non-Euclidian FLIM phasor analysis for a three-component system informed with the vibrational signature of one of the components retrieved with CRI, we were able to semi-quantitatively describe the spatial distribution of drugs in tissue with molecular specificity and cellular resolution.