Abstract: A method of prolonging the activity of a physiologically active agent by prolonging the agent's contact with the skin, even in the presence of water which would normally flush the agent away. The method comprises dissolving the agent in a non-ionic water insoluble surfactant, molecules of which have a hydrophilic portion and a lipophilic portion and a hydrophilic-lipophilic balance of 12 or less, and administering this composition to the skin. The lipophilic portion has an affinity for the lipids in the skin and the hydrophilic portion an affinity for moisture. As a result, the base is not easily washed off, even in the presence of water, and the base itself functions as an effective skin moisturizer as well as an effective and retentive carrier for the physiologically active agent.