Cosmetic and dermatological formulations comprising at least one hydrophilic active ingredient and at least one dialkyl naphthalate which is characterized by the structural formula ##STR00001## in which R.sup.1 and R.sup.2, independently of one another, are selected from the group of branched and unbranched alkyl groups having 6 to 24 carbon atoms, have been found to be stable and effective, particularly in moisturizing the skin or protection the skin from skin aging.