Evaluation of the effect of hydroxypropyl-β-cyclodextrin on topical administration of milk thistle extract

► Cyclodextrins activity as penetration enhancers was demonstrated by in vivo tests. ► Complexation between cyclodextrin and milk thistle extract was proved. ► Comparison between formulations with or without cyclodextrins was done. ► Cyclodextrins effect on antioxidant activity and stability of extract was showed.