Permeant Lipophilicity and Vehicle Composition Influence Accumulation of Dyes in Hair Follicles of Human Skin

The study investigated how the lipophilicity of permeants (dyes) and the composition of the vehicle (solution used for delivery) affect their accumulation in human hair follicles. Using confocal laser scanning microscopy (CLSM), it was found that the low lipophilicity dye Oregon Green® 488 had a higher flux in citric acid buffer, while the more lipophilic dyes Bodipy® FL C5 and Bodipy® 564/570 C5 showed higher fluxes in solutions containing surfactants and propylene glycol. The results indicated that follicular accumulation of dyes increased with the use of lipophilic dyes and when these dyes were applied in a vehicle containing surfactants and propylene glycol. The conclusion was that the targeting of drugs to hair follicles can be enhanced by using lipophilic drugs in combination with surfactant-propylene glycol solutions.