CORRELATION BETWEEN PERCUTANEOUS PENETRATION OF METHYL NICOTINATE ANDSENSITIVE SKIN, USING LASER-DOPPLER IMAGING

Cutaneous penetration of methyl nicotinate has been investigated in 20 women divided into reactors and non-reactors on the basis of response to 10% aqueous solution of lactic acid. The vasodilation induced was measured using a laser Doppler perfusion imager (LDPI) every 5 min for 1 h after application of methyl nicotinate. The intensity and duratio n of inflammation generated by methyl nicotinate were used to assess p enetration or this chemical in persons with sensitive skin compared to those with normal skin. Significant differences were found between re actors and nonreactors. Reactors showed a significantly increased inte nsity of response to methyl nicotinate as early as 5 min after applica tion, and for 30 min afterwards, though the duration of inflammation i n these 2 groups was the same. Correlation between increased penetrati on of methyl nicotinate and skin response to lactic acid may suggest i ncreased penetration of water-soluble chemicals in individuals with se nsitive skin.