A system for delivering a therapeutic agent to a nasopharyngeal mucosa target comprises a foam generating mechanism, a gas, a therapeutic agent in liquid form that inhibits mucus production, and a delivery device. Actuation of the foam generating mechanism entraps gaseous bubbles from the gas in the liquid thereby forming a foam. The therapeutic agent is dispersed in the foam which has an expanded configuration adapted to fill a nasopharyngeal space and deliver the therapeutic agent to the mucosa targets. The delivery device is for delivering the foam to the nasopharyngeal space. The foam may also have a collapsed configuration for removal from the nasopharyngeal space or for concentration of the therapeutic agent onto the mucosa.