Salts or co-crystals of 3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol

1. A salt or cocrystal of

(a) (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol, and

(b1) at least one acid selected from the group consisting of embonic acid, (2S,3S)-dibenzoyltartaric acid, sebacic acid, and 1-hydroxy-2-naphthoic acid, or

(b2) at least one acid selected from the group consisting of nicotinic acid, hydrogen bromide, fumaric acid, and malonic acid

wherein the salt or cocrystal of component (a) and component (b1) or the salt or cocrystal of component (a) and component (b2) is present in crystalline form, and

wherein said crystalline form is selected from the group consisting of:

a salt or cocrystal of embonic acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 7.94±0.20 (2θ), 10.40±0.20 (2θ), 14.25±0.20 (2θ), 17.18±0.20 (2θ) and 18.77±0.20 (2θ) or at least one or more X-ray diffraction peaks selected from the group consisting of 6.00±0.20 (2θ), 11.96±0.20 (2θ) and 17.61±0.20 (2θ);

a hemi salt or cocrystal of (2S,3S)-dibenzoyltartaric acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 9.35±0.20 (2θ), 12.22±0.20 (2θ), 13.41±0.20 (2θ), 14.00±0.20 (2θ), 17.89±0.20 (2θ), 18.28±0.20 (2θ), 18.73±0.20 (2θ), 19.53±0.20 (2θ), 19.98±0.20 (2θ), 23.19±0.20 (2θ) and 24.33±0.20 (2θ);

a salt or cocrystal of sebacic acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 12.16±0.20 (2θ), 15.31±0.20 (2θ), 16.88±0.20 (2θ), 18.90±0.20 (2θ), 22.66±0.20 (2θ), 23.08±0.20 (2θ) and 25.46±0.20 (2θ);

a salt or cocrystal of 1-hydroxy-2-naphthoic acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 13.59±0.20 (2θ), 13.97±0.20 (2θ), 15.36±0.20 (2θ), 18.04±0.20 (2θ), 19.75±0.20 (2θ), 19.98±0.20 (2θ), 20.52±0.20 (2θ), 24.37±0.20 (2θ) and 26.09±0.20 (2θ);

a salt or cocrystal of nicotinic acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 12.60±0.20 (2θ), 15.61±0.20 (2θ) and 22.82±0.20 (2θ) or at least one or more X-ray diffraction peaks selected from the group consisting of 10.34±0.20 (2θ), 12.14±0.20 (2θ), 22.38±0.20 (2θ), 23.65±0.20 (2θ) and 26.11±0.20 (2θ);

a salt or cocrystal of hydrobromic acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 9.93±0.20 (2θ), 14.39±0.20 (2θ), 15.22±0.20 (2θ), 17.60±0.20 (2θ), 20.81±0.20 (2θ), 21.61±0.20 (2θ), 24.37±0.20 (2θ), 24.73±0.20 (2θ), 25.19±0.20 (2θ), 27.14±0.20 (2θ), 27.94±0.20 (2θ), 29.00±0.20 (2θ) and 30.75±0.20 (2θ);

a salt or cocrystal of malonic acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 8.75±0.20 (2θ), 11.85±0.20 (2θ), 13.74±0.20 (2θ), 16.78±0.20 (2θ), 18.09±0.20 (2θ), 19.17±0.20 (2θ), 16.65±0.20 (2θ), 20.45±0.20 (2θ), 21.66±0.20 (2θ), 24.80±0.20 (2θ) and 25.55±0.20 (2θ); and

a hemi salt or cocrystal of fumaric acid and (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol having at least one or more X-ray diffraction peaks selected from the group consisting of 11.86±0.20 (2θ), 15.26±0.20 (2θ), 16.00±0.20 (2θ), 16.21±0.20 (2θ), 17.52±0.20 (2θ), 21.75±0.20 (2θ), 22.35±0.20 (2θ), 24.57±0.20 (2θ) and 25.21±0.20 (2θ).

2. The salt or cocrystal according to claim 1 , wherein component (b1) is selected from the group consisting of embonic acid, sebacic acid, and 1-hydroxy-2-naphthoic acid.

3. The salt or cocrystal according to claim 1 , wherein component (b1) is selected from the group consisting of (2S,3S)-dibenzoyltartaric acid, sebacic acid, 1-hydroxy-2-naphthoic acid, and embonic acid.

4. The salt or cocrystal according to claim 1 , wherein component (b2) is selected from the group consisting of nicotinic acid, hydrogen bromide, fumaric acid, and malonic acid.

5. The salt or cocrystal according to claim 4 , wherein component (b2) is nicotinic acid.

6. The salt or cocrystal according to claim 1 , wherein the stoichiometry of component (a) and (b1) or (b2) is within the range of from 1:0.4 to 1:2.1.

7. The salt or cocrystal according to claim 6 , wherein the stoichiometry of component (a) and (b1) or (b2) is within the range of from 1:0.4 to 1:1.

8. A pharmaceutical composition comprising a salt or cocrystal according to claim 1 and at least one pharmaceutically acceptable carrier or auxiliary.

9. A pharmaceutical composition according to claim 8 , in the form of a solid tablet.

10. A pharmaceutical composition according to claim 8 , wherein said composition is formulated for oral administration.

11. A method of treating pain in a subject in need thereof, said method comprising administering an effective pain relieving amount of a salt or cocrystal according to claim 1 to said subject.

12. A method according to claim 11 , wherein the pain is selected from the group consisting of inflammatory pain, neuropathic pain, acute pain, chronic pain, visceral pain, migraine pain and pain associated with cancer.

13. A method according to claim 11 , wherein said subject is a mammal.

14. A pharmaceutical composition comprising a salt or cocrystal according to claim 8 , wherein component (b1) is selected from the group consisting of embonic acid, sebacic acid, and 1-hydroxy-2-naphthoic acid.

15. A pharmaceutical composition comprising a salt or cocrystal according to claim 8 , wherein component (b2) is selected from the group consisting of nicotinic acid, hydrogen bromide fumaric acid, and malonic acid.

16. A pharmaceutical composition comprising a salt or cocrystal according to claim 8 , wherein the stoichiometry of component (a) and (b1) or (b2) is within the range of from 1:0.4 to 1:2.1.

17. A pharmaceutical composition comprising a salt or cocrystal according to claim 8 , wherein the stoichiometry of component (a) and (b1) or (b2) is within the range of from 1:0.4 to 1:1.