An oral immediate release formulation comprising an active ingredient selected from: 2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)-5,7-dimethoxyquinazolin-4 -one; and the hydrochloride salt thereof; wherein the active ingredient is present: (a) in an amount from 10% to 12% by weight and the formulation further comprises: (i) 82% to 83% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (b) in an amount from 20% to 22% by weight and the formulation further comprises: (i) 70% to 72% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (c) in an amount from 31% to 33% by weight and the formulation further comprises: (i) 60% to 62% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate. or (d) in an amount from 41% to 43% by weight and the formulation further comprises: (i) 50% to 51% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate. 2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)-5,7-dimethoxyquinazolin-4 -one; and the hydrochloride salt thereof; wherein the active ingredient is present: (a) in an amount from 10% to 12% by weight and the formulation further comprises: (i) 82% to 83% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (b) in an amount from 20% to 22% by weight and the formulation further comprises: (i) 70% to 72% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (c) in an amount from 31% to 33% by weight and the formulation further comprises: (i) 60% to 62% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate. or (d) in an amount from 41% to 43% by weight and the formulation further comprises: (i) 50% to 51% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate. (a) in an amount from 10% to 12% by weight and the formulation further comprises: (i) 82% to 83% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (i) 82% to 83% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (b) in an amount from 20% to 22% by weight and the formulation further comprises: (i) 70% to 72% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (i) 70% to 72% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate; (c) in an amount from 31% to 33% by weight and the formulation further comprises: (i) 60% to 62% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate. or (i) 60% to 62% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate. or (d) in an amount from 41% to 43% by weight and the formulation further comprises: (i) 50% to 51% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate. (i) 50% to 51% by weight of microcrystalline cellulose; (ii) 2.5% by weight of colloidal silicon dioxide; (iii) 4.0% by weight of sodium starch glycolate; and (iv) 0.5% by weight of magnesium stearate.