Details for Patent: 7,566,462

Title:	Stable tablet formulation
Abstract:	The present invention is directed to a stable solid formulations of tetrahydrobiopterin, processes for producing them, and treatment methods using such formulations.
Inventor(s):	Jungles; Steven (Novato, CA), Henderson; Mark A. (Larkspur, CA), Sluzky; Victoria (Corte Madera, CA), Baffi; Robert (Moraga, CA)
Assignee:	BioMarin Pharmaceutical Inc. (Novato, CA)
Filing Date:	Apr 21, 2008
Application Number:	12/106,621
Claims:	1. A stable tablet formulation comprising an initial amount of a crystalline polymorph, designated polymorph B, of (6R)-L-erythro-tetrahydrobiopterin dihydrochloride, an antioxidant, and a pharmaceutically acceptable excipient, diluent, or carrier in the form of a tablet, wherein the weight ratio of the antioxidant to the (6R)-L-erythro-tetrahydrobiopterin dihydrochloride is about 1:5 to about 1:30; wherein after six months in a container at room temperature and about 60% humidity the stable tablet formulation retains at least about 95% of the initial amount of (6R)-L-erythro-tetrahydrobiopterin dihydrochloride, and wherein said crystalline polymorph B exhibits an X-ray powder diffraction pattern with the following characteristic peaks expressed in d-values (.ANG.): 8.7 (vs), 5.63 (m), 4.76 (m), 4.40 (m), 4.00 (s), 3.23 (s), and 3.11 (vs). 2. The stable tablet formulation of claim 1, wherein the crystalline polymorph B further exhibits characteristic peaks expressed in d-values (.ANG.): 6.9 (w), 5.07 (m), 4.15 (w), 3.95 (m), 3.52 (m), 3.44 (w), 3.32 (m), 3.17 (w), 3.06 (w), 2.99 (w), 2.96 (w), 2.94 (m), 2.87 (w), 2.84 (s), 2.82 (m), 2.69 (w), 2.59 (w), and 2.44 (w). 3. The stable tablet formulation of claim 1, wherein after six months in a container at room temperature and about 60% humidity the stable tablet formulation retains at least about 98% of the initial amount of (6R)-L-erythro-tetrahydrobiopterin. 4. The stable tablet formulation of claim 1, wherein after nine months in a container at room temperature and about 60% humidity the stable tablet formulation retains at least about 95% of the initial amount of (6R)-L-erythro-tetrahydrobiopterin. 5. The stable tablet formulation of claim 1, wherein after twelve months in a container at room temperature and about 60% humidity the stable tablet formulation retains at least about 95% of the initial amount of (6R)-L-erythro-tetrahydrobiopterin. 6. The stable tablet formulation of claim 1, wherein the initial amount of (6R)-L-erythro-tetrahydrobiopterin is in a range of about 30 wt % to about 40 wt % of the formulation. 7. The stable tablet formulation of claim 1, wherein the initial amount of (6R)-L-erythro-tetrahydrobiopterin in a tablet is selected from the group consisting of 100 mg, 200 mg, and 300 mg. 8. The stable tablet formulation of claim 1, wherein the initial amount of (6R)-L-erythro-tetrahydrobiopterin in a tablet is 400 mg. 9. The stable tablet formulation of claim 1, further comprising a disintegration agent. 10. The stable tablet formulation of claim 9, wherein the disintegration agent is crospovidone. 11. The stable tablet formulation of claim 1, further comprising a lubricant. 12. The stable tablet formulation of claim 11, wherein the lubricant is stearyl fumarate. 13. The stable tablet formulation of claim 12, wherein the stearyl fumarate is sodium stearyl fumarate. 14. The stable tablet formulation of claim 11, wherein the lubricant is present in a range of about 1.0 wt % to about 1.8 wt % of the formulation. 15. The stable tablet formulation of claim 12, further comprising microcrystalline cellulose. 16. The stable tablet formulation of claim 1, comprising an initial amount of the (6R)-L-erythro-tetrahydrobiopterin of about 400 mg, crospovidone in a range of about 3 wt % to about 5 wt % of the formulation, and stearyl fumarate in a range of about 1 wt % to about 1.7 wt % of the formulation. 17. The stable tablet formulation of claim 1, comprising an initial amount of the (6R)-L-erythro-tetrahydrobiopterin in a range of about 32 wt % to about 35 wt % of the formulation, crospovidone in a range of about 3 wt % to about 5 wt % of the formulation, anhydrous dibasic calcium phosphate in a range of about 1.5 wt % to about 3 wt % of the formulation, and stearyl fumarate in a range of about 0.5 wt % to about 2 wt % of the formulation. 18. The stable tablet formulation of claim 1, wherein the antioxidant is an acidic antioxidant. 19. The stable tablet formulation of claim 1, wherein the antioxidant is ascorbic acid. 20. The stable tablet formulation of claim 19, wherein the weight ratio of ascorbic acid to the (6R)-L-erythro-tetrahydrobiopterin dihydrochloride is about 1:20.