A smoking article comprising a filter element, a tobacco rod, and at least one breakable capsule, the breakable capsule comprising: an outer shell formed of a cross-linked agar matrix including at least one filler, the at least one filler including locust bean gum; and an inner core surrounded by the outer shell which comprises a liquid or gel based composition of a flavorant, a non-flavorant, or both a flavorant and a non-flavorant; wherein the cross-linked agar matrix is reinforced with carboxymethyl cellulose dispersed throughout the agar matrix so as to fill empty spaces in the agar matrix and inhibit the composition from passing through the empty spaces of the agar matrix, and wherein (a) the outer shell of the breakable capsule has a diameter of 2 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1 to 0.05 to 0.05; (b) the outer shell of the breakable capsule has a diameter of 2.5 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1.4 to 0.05 to 0.05; or (c) the outer shell of the breakable capsule has a diameter of 2.5 to 4.5 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1.4-2 to 0.05-0.5 to 0.05-0.5. an outer shell formed of a cross-linked agar matrix including at least one filler, the at least one filler including locust bean gum; and an inner core surrounded by the outer shell which comprises a liquid or gel based composition of a flavorant, a non-flavorant, or both a flavorant and a non-flavorant; wherein the cross-linked agar matrix is reinforced with carboxymethyl cellulose dispersed throughout the agar matrix so as to fill empty spaces in the agar matrix and inhibit the composition from passing through the empty spaces of the agar matrix, and wherein (a) the outer shell of the breakable capsule has a diameter of 2 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1 to 0.05 to 0.05; (b) the outer shell of the breakable capsule has a diameter of 2.5 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1.4 to 0.05 to 0.05; or (c) the outer shell of the breakable capsule has a diameter of 2.5 to 4.5 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1.4-2 to 0.05-0.5 to 0.05-0.5. (a) the outer shell of the breakable capsule has a diameter of 2 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1 to 0.05 to 0.05; (b) the outer shell of the breakable capsule has a diameter of 2.5 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1.4 to 0.05 to 0.05; or (c) the outer shell of the breakable capsule has a diameter of 2.5 to 4.5 mm, and the ratio of agar to locust bean gum to carboxymethyl cellulose in an aqueous shell forming solution used to form the outer shell is 1.4-2 to 0.05-0.5 to 0.05-0.5.