“Pretreatment of porcine skin with ethanol (vehicle), polyethylene glycol 600, Span 20, oleic acid, R-(+)-limonene , alpha-bisabolol and 1,8-cineole (at 5% in ethanol, w/w) produced in all cases an increase in the flux of sumatriptan.”
“ R-(+)-limonene showed the greatest ability to enhance the flux of sumatriptan.”