A patient with atopic dermatitis who was allergic to lanolin, as well as almost all preservatives, required a topical immuno-suppressive drug to be compounded in a hydrophilic petrolatum base. We worked closely with the patient and the physician to design a preservative free base that we could use to incorporate the drug into, thereby allowing the condition to be treated in a manner which removed all of the allergenic items from the ointment base.