Composition comprises a fatty phase, an aqueous phase and a compound of avermectin family, where the fatty phase comprises an oily solvent different from mineral and vegetable oils, in which the avermectin compound is solubilized. An independent claim is included for the preparation of the composition comprising mixing ivermectin with an oily solvent, until ivermectin is solubilized, to form the fatty phase, mixing constituents of the aqueous phase, up to homogeneity and incorporating the fatty phase in the aqueous phase to form an emulsion. ACTIVITY : Dermatological; Antiseborrheic. MECHANISM OF ACTION : None given.