A film suitable for administration to an oral cavity comprising: (i) an alginate salt of a monovalent cation or a mixture of alginate salts containing at least one alginate salt of a monovalent cation; (ii) an active pharmaceutical ingredient (API) which is a compound of Formula (I) wherein: Ar is selected from X is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Y is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Z is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Q is selected from -CH 2 -, -CH(OH)-, -CH(Me)-, -CH(OMe)-, -(C=O)-, -(C=S)- and -(C=NR)-, wherein R is selected from hydrogen or C 1-6 alkyl; R 1 is selected from hydrogen and C 1-6 alkyl and R 2 is selected from hydrogen, C 1-6 alkyl optionally substituted with halo, hydroxyl, C 1-4 alkoxy, amino or C 1-4 alkylamino, and C 1-6 alkenyl, or R 1 and R 2 are linked so as to form a bivalent alkylene moiety having from 3 to 7 carbon atoms; and (iii) an acid H x A, wherein A is a counterion having an ionic radius of 2.65 Å or greater, and x is a positive integer which is equal to the charge on the counterion A; further wherein the alginate salt of a monovalent cation (a) comprises from 25 to 35% by weight of β-D-mannuronate and/or from 65 to 75% by weight of α-L-guluronate, and (b) has a weight average molecular weight of from 30,000 g/mol to 90,000 g/mol. (i) an alginate salt of a monovalent cation or a mixture of alginate salts containing at least one alginate salt of a monovalent cation; (ii) an active pharmaceutical ingredient (API) which is a compound of Formula (I) wherein: Ar is selected from X is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Y is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Z is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Q is selected from -CH 2 -, -CH(OH)-, -CH(Me)-, -CH(OMe)-, -(C=O)-, -(C=S)- and -(C=NR)-, wherein R is selected from hydrogen or C 1-6 alkyl; R 1 is selected from hydrogen and C 1-6 alkyl and R 2 is selected from hydrogen, C 1-6 alkyl optionally substituted with halo, hydroxyl, C 1-4 alkoxy, amino or C 1-4 alkylamino, and C 1-6 alkenyl, or R 1 and R 2 are linked so as to form a bivalent alkylene moiety having from 3 to 7 carbon atoms; and Ar is selected from X is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Y is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Z is selected from hydrogen, halo, OH, NH 2 , methyl, trifluoromethyl and methoxy; Q is selected from -CH 2 -, -CH(OH)-, -CH(Me)-, -CH(OMe)-, -(C=O)-, -(C=S)- and -(C=NR)-, wherein R is selected from hydrogen or C 1-6 alkyl; R 1 is selected from hydrogen and C 1-6 alkyl and R 2 is selected from hydrogen, C 1-6 alkyl optionally substituted with halo, hydroxyl, C 1-4 alkoxy, amino or C 1-4 alkylamino, and C 1-6 alkenyl, or R 1 and R 2 are linked so as to form a bivalent alkylene moiety having from 3 to 7 carbon atoms; and (iii) an acid H x A, wherein A is a counterion having an ionic radius of 2.65 Å or greater, and x is a positive integer which is equal to the charge on the counterion A; <EOS>