Nasal or sinus site may be treated with a ready-to-use paste having a high concentration of a water-soluble chitosan, an osmolality reducing agent in a phosphate-containing solution. The paste forms at room temperature, has a pH of at least 4 and the osmolality reducing agent does not crosslink with the water-soluble chitosan. The paste provides stenting and adheres to the nasal or sinus site and has a residence time of at least 1 day.
