Pharmaceutical formulation comprising one or more fumaric acid esters in an erosion matrix

1. A pharmaceutical formulation in the form of an erosion matrix tablet comprising:

a) a core tablet comprising

i) 10% to 80% by weight of one or more fumaric acid esters selected from di-(C 1 -C 5 )alkylesters of fumaric acid and mono-(C 1 -C 5 )alkylesters of fumaric acid, or a pharmaceutically acceptable salt thereof, as an active substance;

ii) 1-50% by weight of one or more rate-controlling agents; and

b) an enteric coating, wherein said enteric coating is applied at a level of 1.5-3.5% by weight of the core,

wherein erosion of said erosion matrix permits controlled or sustained release of said active substance.

2. A pharmaceutical formulation according to claim 1 comprising:

i) 30% to 60% by weight of one or more fumaric acid esters selected from di-(C 1 -C 5 )alkylesters of fumaric acid and mono-(C 1 -C 5 )alkylesters of fumaric acid, or a pharmaceutically acceptable salt thereof, as an active substance;

ii) 3-40% by weight of one or more rate-controlling agents.

3. A pharmaceutical formulation according to claim 1 , wherein the erosion matrix is a monolithic erosion matrix.

4. The formulation according to claim 1 , wherein the rate-controlling agent is a water-soluble polymer.

5. The formulation according to claim 1 , wherein the rate-controlling agent is a cellulose polymer or a cellulose derivative or a mixture thereof.

6. The formulation according to claim 5 , wherein the rate-controlling agent is selected from the group comprising hydroxypropyl cellulose, hydroxypropyl methyl cellulose (HPMC), methyl cellulose, carboxymethyl cellulose and mixtures thereof.

7. The formulation according to claim 6 , wherein the rate-controlling agent is hydroxypropyl cellulose.

8. The formulation according to claim 1 , further comprising a binder.

9. The formulation according to claim 8 , wherein said binder is lactose.

10. The formulation according to claim 1 comprising:

i) 40% to 60% by weight of one or more fumaric acid esters selected from di-(C 1 -C 5 )alkylesters of fumaric acid and mono-(C 1 -C 5 )alkylesters of fumaric acid, or a pharmaceutically acceptable salt thereof, as an active substance;

ii) 4-6% by weight of a rate-controlling agent;

iii) 35-55% by weight of a binder.

11. The formulation according to claim 1 comprising:

i) 30% to 60% by weight of one or more fumaric acid esters selected from di-(C 1 -C 5 )alkylesters of fumaric acid and mono-(C 1 -C 5 )alkylesters of fumaric acid, or a pharmaceutically acceptable salt thereof, as an active substance;

ii) 3-6% by weight of a rate-controlling agent;

iii) 35-65% by weight of a binder.

12. The formulation according to claim 1 , wherein the release of the fumaric acid ester—when subjected to an in vitro dissolution test employing 0.1 N hydrochloric acid as dissolution medium during the first 2 hours of the test and then 0.05 M phosphate buffer pH 6.8 as dissolution medium—is as follows:

within the first 2 hours after start of the test from about 0% w/w to about 50% w/w of the fumaric ester contained in the formulation is released, and/or

within the first 3 hours after start of the test from about 20% w/w to about 75% w/w of the total amount of the fumaric acid ester contained in the formulation is released.

13. The formulation according to claim 1 , wherein the fumaric acid ester is a mono-(C 1 -C 5 ) alkylester of fumaric acid that is present in the form of a pharmaceutically acceptable salt.

14. The formulation according to claim 1 comprising dimethylfumarate as the active substance.

15. The formulation according to claim 1 comprising:

i) 40% to 55% by weight of dimethyl fumarate;

ii) 4-6% by weight of hydroxypropyl cellulose;

iii) 35-55% by weight of lactose.

16. The formulation according to claim 1 comprising:

i) 30% to 60% by weight of dimethyl fumarate;

ii) 3-6% by weight of hydroxypropyl cellulose;

iii) 35-65% by weight of lactose.

17. A method for preparing the formulation according to claim 1 comprising the steps of:

a) Dissolving or suspending a rate-controlling agent in the form of a polymeric matrix material in water to obtain an aqueous suspension thereof;

b) Spraying said aqueous suspension on granules of a fumaric acid ester for a period of time sufficient to obtain a uniform coating thereon;

c) Drying the granules obtained;

d) Optionally sieving or milling said granules;

e) Blending of any pharmaceutically acceptable excipients and additives in a manner known per se to obtain a tablet formulation;

f) enteric coating of said tablet formulation in a manner known per se;

wherein the above steps are performed at a temperature to allow a product temperature not exceeding 45° C.

18. A method for preparing the formulation according to claim 1 comprising the steps of:

a) Optionally sieving or milling crystals of fumaric acid ester;

b) Blending of said crystals of fumaric acid ester, a rate-controlling agent in the form of a polymeric matrix material, and any pharmaceutically acceptable excipients and additives by direct compression to obtain a tablet formulation;

c) enteric coating of said tablet formulation in a manner known per se;

wherein the above steps are performed at a temperature to allow a product temperature not exceeding 45° C.

19. The method according to claim 18 , wherein the crystals of fumaric acid ester are sieved or milled such that 90% of the particles have a particle size in the range of 5-1000 μm.

20. A pharmaceutical formulation according to claim 1 for use for the treatment of psoriasis, psoriatic arthritis, neurodermatitis, inflammatory bowel disease, such as Crohn's disease and ulcerative colitis, polyarthritis, multiple sclerosis (MS), juvenile-onset diabetes mellitus, Hashimoto's thyroiditis, Grave's disease, SLE (systemic lupus erythematosus), Sjögren's syndrome, Pernicious anemia, Chronic active (lupoid) hepatitis, Rheumatoid arthritis (RA), lupus nephritis, myasthenia gravis, uveitis, refractory uveitis, vernal conjunctivitis, pemphigus vulgaris, scleroderma, optic neuritis, pain such as radicular pain, pain associated with radiculopathy, neuropathic pain or sciatica/sciatic pain, organ transplantation (prevention of rejection), sarcoidosis, necrobiosis lipoidica or granuloma annulare.

21. A use of a pharmaceutical formulation according to claim 1 for the preparation of a medicament for the treatment of psoriasis, psoriatic arthritis, neurodermatitis, inflammatory bowel disease, such as Crohn's disease and ulcerative colitis, polyarthritis, multiple sclerosis (MS), juvenile-onset diabetes mellitus, Hashimoto's thyroiditis, Grave's disease, SLE (systemic lupus erythematosus), Sjögren's syndrome, Pernicious anemia, Chronic active (lupoid) hepatitis, Rheumatoid arthritis (RA), lupus nephritis, myasthenia gravis, uveitis, refractory uveitis, vernal conjunctivitis, pemphigus vulgaris, scleroderma, optic neuritis, pain such as radicular pain, pain associated with radiculopathy, neuropathic pain or sciatica/sciatic pain, organ transplantation (prevention of rejection), sarcoidosis, necrobiosis lipoidica or granuloma annulare.