Nanoemulsion, method for its preparation and use

A nanoemulsion with a micellar size of 20 to 900 nm comprising: a) an active ingredient of interest in the pharmaceutical, cosmetic or food field b) an aqueous phase c) a lipid phase, and d) emulsifying agents, wherein: * said aqueous phase comprises a base; * the emulsifying agents d) consist of d1) ascorbyl palmitate, d2) one or more polyoxyethylene sorbitan esters and optionally d3) glycocropeptide; * said one or more polyoxyethylene sorbitan esters are comprised in said lipid phase c) * said ascorbyl palmitate is comprised in said aqueous phase or in said lipid phase or in both of said phases, * said active ingredient a) is selected from melatonin and fat soluble vitamins.