Hair follicle targeting with curcumin nanocrystals: Influence of the formulation properties on the penetration efficacy

This study investigated the efficacy of curcumin nanocrystals (300 nm) in penetrating hair follicles using different gel formulations on an ex-vivo pig ear model. The nanocrystals effectively reached the lower part of the hair follicle infundibulum, an optimal region for drug delivery due to its permeability. The type of gel vehicle (oleogels or hydrogels) did not significantly affect follicular penetration, as all gels exhibited shear-thinning behavior, leading to similar penetration results. However, passive dermal penetration varied, with hydrogels containing humectants showing the best results. Notably, humectants reduced follicular penetration efficacy, suggesting that while nanocrystals in simple, shear-thinning gels are effective for follicle targeting, additional excipients like humectants may alter penetration profiles, warranting further research.