A solid controlled release formulation for the oral administration of lacosamide, the composition comprising lacosamide and a lacosamide release controlling agent, wherein a. an amount of about 8.5 wt% to about 50 wt% of lacosamide relative to the total lacosamide content of the formulation is released within 1 h, b. an amount of about 15 wt% to about 70 wt% of lacosamide relative to the total lacosamide content of the formulation is released within 2 h, and c. an amount of about 28 wt% to about 90 wt% of lacosamide relative to the total lacosamide content of the formulation is released within 4 h, when the in-vitro release of lacosamide is measured according to USP (edition 24) method <711>, dissolution apparatus 2, in 900 mL of 0.1N HCI at 75 rpm, wherein the lacosamide release controlling agent is present in the matrix of the formulation (a "matrix retardation agent") and is selected from i) cellulose derivatives such as hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, and hydroxypropylmethylcellulose (HPMC), and having a viscosity of 2,000 mPa·s to 200,000 mPa·s in a 2 wt-% aqueous solution at 20 °C, when measured using Ubbelohde capillary viscosity, ii) a polyethylene glycol having a viscosity given as a 1% solution in water at 25 °C of between about 1,000 and 50,000 mPas, iii) starch having a viscosity given as a 2% solution in water at 25 °Cof between about 20 and 200 mPa·s when measured using Ubbelohde capillary viscosity, iv) xanthan having a viscosity given as a 1% solution in water at 25 °Cof between about 500 and 2000 mPa·s when measured using Ubbelohde capillary viscosity, v) an inert polymer selected from the group of polyvinyl acetate, methacrylic acid copolymer type A, methacrylic acid copolymer type B, methacrylic acid copolymer type C, ammonio methacrylate copolymer type A, ammonio methacrylate copolymer type B, neutral ethyl methyl methacrylate copolymer and basic butylated methacrylate copolymer, and vi) low viscosity hydrophilic retardation agent selected from HPMC having a viscosity of between about 600 and 2000 mPa·s in a 2 wt-% solution at 20°C when measured using Ubbelohde capillary viscosity and HPC having a viscosity of between about 200 and 3000 mPa·s in an up to 10 wt-% aqueous solution at 20°C wherein the amount of such low viscosity hydrophilic retardation agent is at least 12 wt% relative to the total weight of the formulation. a. an amount of about 8.5 wt% to about 50 wt% of lacosamide relative to the total lacosamide content of the formulation is released within 1 h, b. an amount of about 15 wt% to about 70 wt% of lacosamide relative to the total lacosamide content of the formulation is released within 2 h, and c. an amount of about 28 wt% to about 90 wt% of lacosamide relative to the total lacosamide content of the formulation is released within 4 h, i) cellulose derivatives such as hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, and hydroxypropylmethylcellulose (HPMC), and having a viscosity of 2,000 mPa·s to 200,000 mPa·s in a 2 wt-% aqueous solution at 20 °C, when measured using Ubbelohde capillary viscosity, ii) a polyethylene glycol having a viscosity given as a 1% solution in water at 25 °C of between about 1,000 and 50,000 mPas, iii) starch having a viscosity given as a 2% solution in water at 25 °Cof between about 20 and 200 mPa·s when measured using Ubbelohde capillary viscosity, iv) xanthan having a viscosity given as a 1% solution in water at 25 °Cof between about 500 and 2000 mPa·s when measured using Ubbelohde capillary viscosity, v) an inert polymer selected from the group of polyvinyl acetate, methacrylic acid copolymer type A, methacrylic acid copolymer type B, methacrylic acid copolymer type C, ammonio methacrylate copolymer type A, ammonio methacrylate copolymer type B, neutral ethyl methyl methacrylate copolymer and basic butylated methacrylate copolymer, and vi) low viscosity hydrophilic retardation agent selected from HPMC having a viscosity of between about 600 and 2000 mPa·s in a 2 wt-% solution at 20°C when measured using Ubbelohde capillary viscosity and HPC having a viscosity of between about 200 and 3000 mPa·s in an up to 10 wt-% aqueous solution at 20°C wherein the amount of such low viscosity hydrophilic retardation agent is at least 12 wt% relative to the total weight of the formulation.