Patent ID: 7727987

Claim:
A crystalline form of (6R)-L-erythro-tetrahydrobiopterin dihydrochloride, which exhibits a characteristic X-ray powder diffraction pattern with characteristic peaks expressed in d-values (Å): for form A, which is a crystalline polymorph: 15.5 (vs), 12.0 (m), 4.89 (m), 3.70 (s), 3.33 (s), 3.26 (s), and 3.18 (m); or for form F, which is a crystalline polymorph: 17.1 (vs), 4.92 (m), 4.68 (m), 3.49 (s), 3.46 (vs), 3.39 (s), 3.21 (m), and 3.19 (m); or for form J, which is a crystalline polymorph: 14.6 (m), 3.29 (vs), and 3.21 (vs); or for form K, which is a crystalline polymorph: 14.0 (s), 6.6 (w), 4.73 (m), 4.64 (m), 3.54 (m), 3.49 (vs), 3.39 (m), 3.33 (vs), 3.13 (s), 3.10 (m), 3.05 (m), 3.01 (m), 2.99 (m), and 2.90 (m); or for form C, which is a crystalline hydrate: 13.9 (vs), 8.8 (m), 6.8 (m), 6.05 (m), 4.25 (m), 4.00 (m), 3.88 (m), 3.80 (m), 3.59 (s), 3.50 (m), 3.44 (m), 3.26 (s), 3.19 (vs), 3.17 (s), 3.11 (m), 2.97 (m), and 2.93 (vs); or for form D, which is a crystalline hydrate: 8.6 (s), 5.56 (m), 4.99 (m), 4.67 (s), 4.32 (m), 3.93 (vs), 3.17 (m), 3.05 (s), 2.88 (m), and 2.79 (m); or for form E, which is a crystalline hydrate: 15.4 (s), 4.87 (w), 3.69 (m), 3.33 (s), 3.26 (vs), 3.08 (m), 2.95 (m), and 2.87 (m); or for form H, which is a crystalline hydrate: 15.8 (vs), 3.87 (m), 3.60 (m), 3.27 (m), 3.21 (m), 2.96 (m), 2.89 (m), and 2.67 (m); or for form O, which is a crystalline hydrate: 8.8 (m), 6.3 (m), 5.65 (m), 5.06 (m), 4.00 (m), 3.88 (m), 3.69 (s), 3.64 (s), 3.52 (vs), 3.49 (s), 3.46 (s), 3.42 (s), 3.32 (m), 3.27 (m), 3.23 (s), 3.18 (s), 3.15 (vs), 3.12 (m), and 3.04 (vs); or for form G, which is a crystalline ethanol solvate: 14.5 (vs), 7.0 (w), 4.41 (w), 3.63 (m), 3.57 (m), 3.49 (w), 3.41 (m), 3.26 (m), 3.17 (m), 3.07 (m), 2.97 (m), 2.95 (m), 2.87 (w), and 2.61 (w); or for form I, which is a crystalline acetic acid solvate: 14.5 (m), 3.67 (vs), 3.61 (m), 3.44 (m), 3.11 (s), and 3.00 (m); or for form L, which is a crystalline mixed ethanol solvate/hydrate: 14.1 (vs), 10.4 (w), 6.9 (w), 6.5 (w), 6.1 (w), 4.71 (w), 3.46 (m), 3.36 (m), and 2.82 (w); or for form M, which is a crystalline ethanol solvate: 18.9 (s), 6.4 (m), and 3.22 (vs); or for form N, which is a crystalline polymorph: 19.5 (m), 6.7 (w), 3.56 (m), and 3.33 (vs), 3.15 (w).