Described here are systems and methods for delivering an active agent to target tissues of the ear, nose, or throat using an expandable member having drug crystals layered thereon, and methods for manufacturing such systems. The expandable member can be delivered to the target tissues in a low-profile configuration and expanded to contact and/or dilate surrounding tissue. Expansion of the expandable member transfers the drug crystals to the target tissues, which then act as an in situ depot that enables maintenance of a therapeutic level of an active agent for a desired time period after removal of the expandable member. Multiple expansions of a single expandable member can be employed during treatment. For example, the systems and methods can be useful when it is desired to treat multiple paranasal sinuses with a single expandable member.
