Abstract: An aqueous solution comprising a cationic polymer dissolved in water, wherein said cationic polymer comprises a hydrophobic quaternary ammonium group covalently attached to a hydroxyethyl cellulose polymer backbone. Also, a method of delivering a drug to a mucosal surface in a living body, said method comprising applying the aqueous solution to said mucosal surface.

Abstract: An aqueous solution comprising a cationic polymer dissolved in water, wherein said cationic polymer comprises a hydrophobic quaternary ammonium group covalently attached to a hydroxyethyl cellulose polymer backbone. Also, a method of delivering a drug to a mucosal surface in a living body, said method comprising applying the aqueous solution to said mucosal surface.

Abstract: A composition designed for application to a mucosa comprises i) a tonicity-adjusting agent, ii) an aqueous liquid diluent, and iii) 0.1 to 6 weight percent of a cellulose ether having a viscosity of up to 8000 mPa·s, wherein the cellulose ether has anhydroglucose units joined by 1-4 linkages and has methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl as substituents such that hydroxyl groups of anhydroglucose units are substituted with methyl groups such that s23/s26 is 0.29 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 3-positions of the anhydroglucose unit are substituted with a methyl group and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 6-positions of the anhydroglucose unit are substituted with a methyl group.

Abstract: A composition designed for application to a mucosa comprises a tonicity-adjusting agent, a methylcellulose, and a liquid diluent, wherein the methylcellulose has anhydroglucose units joined by 1-4 linkages wherein hydroxy groups of anhydroglucose units are substituted with methyl groups such that s23/s26 is 0.36 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 3-positions of the anhydroglucose unit are substituted with methyl groups and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 6-positions of the anhydroglucose unit are substituted with methyl groups.