Crystalline phases of 5,6-dichloro-2-(isopropylamino)-1-β-L-ribofuranosyl-1H-benzimidazole

1. Crystalline Form VIII of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole having an X-ray powder diffraction pattern substantially as shown in FIG. 1 .

2. A crystalline form of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole having an X-ray powder diffraction pattern selected from the group consisting of those substantially as shown in FIGS. 2-15 .

3. A crystalline solvate form of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole, including a stoichiometric ratio of an organic solvent within at least one cavity of the crystal lattice, said solvent being selected from the group of methanol, ethyl formate, t-butylmethyl ether, acetonitrile, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isopropyl ether, 1,2-dimethoxyethane, toluene, 2,2-dimethyl-3-butanone, hexafluorbenzene, nitrobenzene, 1,4-dioxane, tetrahydrofuran (THF), n-heptane, cyclohexane, methylbutyrate, or mixtures thereof.

4. A pharmaceutical composition comprising a crystalline form of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole according to claim 1 and at least one pharmaceutically acceptable carrier.

5. A pharmaceutical composition according to claim 4 in the form of a powder, tablet, capsule or suspension.

6. A composition comprising an admixture of crystalline Form VIII of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole, together with at least one of Form I, Form II, ethanol solvate, Form IV, Form V, Form VI and amorphous 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole.

7. A composition comprising an admixture of a crystalline form of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole according to claim 2 together with at least one of Form I, Form II, ethanol solvate, Form IV, Form V, Form VI and amorphous 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole.

8. A method for treatment or prophylaxis of a herpes viral infection in a patient in need thereof comprising administering to said patient an effective anti-viral amount of crystalline Form VIII of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole according to claim 1 .

9. A method according to claim 8 , wherein said herpes viral infection is cytomegalovirus (CMV).

10. A method for treatment or prophylaxis of a herpes viral infection in a patient in need thereof comprising administering to said patient an effective anti-viral amount of a crystalline form of 5,6-dichloro-2-(isopropylamino)-1-(β-L-ribofuranosyl)-1H-benzimidazole according to claim 2 .

11. A method according to claim 10 , wherein said herpes viral infection is cytomegalovirus (CMV).

12. The crystalline solvate of claim 3 , wherein said cavity (or cavities) including said solvent or solvent mixture occupies between about 3.3 to about 18.5% of the unit cell volume.

13. The crystalline solvate of claim 12 , wherein said cavity or cavities also includes water.