Pharmaceutical preparations comprised of a pharmaceutically active ingredient and a carrier which comprises a percutaneous penetration enhancer comprised of 2-ethyl-1, 3-hexanediol alone or in combination with oleic acid is disclosed. The 2-ethyl-1, 3-hexanediol may be present in an amount in the range of about 50% to 100% based on the weight of the carrier. The oleic acid may be used in combination with 2-ethyl-1, 3-hexanediol in an amount of about 1 to 40% based on the weight of the carrier to provide a synergistic effect with respect to percutaneous penetration enhancement. The compound 2-ethyl-1, 3-hexanediol as used alone and/or in combination with the oleic acid has been found to significantly enhance the delivery of a drug, to a patient, from a transdermal delivery system.