A dry formulation may include one or more active agents including one or more anti-infective agents such as an anti-bacterial agent, anti-fungal agent, or other anti-active agent. The dry formulation may be prepared for administration by mixing the dry formulation with a diluent. In one example, the diluent is a hydrocortisone and acetic acid solution or a sodium chloride solution. The combined preparation may be administered to the ear or skin to treat or prevent an infection.