Solid forms of (1r,4r)-6′-fluoro-N,N-dimethy1-4-phenyl-4′,9′-dihydro-3′ H-spiro-[cyclohexane-1,1′-pyrano-[3,4,b]indol]-4-amine hydrochloride

1. A crystalline form of (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro[cyclohexane-1,1′-pyrano[3,4,b]indol]-4-amine hydrochloride, which has

one or more X-ray diffraction peaks (CuKα radiation) selected from the group consisting of 10.6±0.2 (2Θ), 17.2±0.2 (2Θ), 18.6±0.2 (2Θ), 19.3±0.2 (2Θ), 22.2±0.2 (2Θ), 26.7±0.2 (2Θ), 29.3±0.2 (2Θ); and/or one or more Raman peaks selected from the group consisting of 183±2 cm −1 , 919±2 cm −1 , 1001±2 cm −1 , 1300±2 cm −1 , 1569±2 cm −1 , 1583±2 cm −1 , 2992±2 cm −1 , 3054±2 cm −1 and 3069±2 cm −1 .

2. The crystalline form according to claim 1 , which is an ansolvate.

3. The crystalline form according to claim 1 , which upon DSC analysis exhibits an endothermal event with an onset temperature or a peak temperature in the range of 262-270° C.

4. A pharmaceutical composition comprising the crystalline form according to claim 1 and at least one pharmaceutically acceptable carrier or auxiliary.

5. A process for obtaining a solid form of (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro[cyclohexane-1,1′-pyrano[3,4,b]indol]-4-amine hydrochloride according to claim 1 , said process comprising:

(a-1) adding hydrogen chloride to a solution or suspension of the free base (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro[cyclohexane-1,1′-pyrano[3,4,b]indol]-4-amine in a mixture of acetone and THF to form the hydrochloride salt of (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro[cyclohexane-1,1′-pyrano[3,4,b]indol]-4-amine, wherein the mixture comprises acetone and THF in a ratio from 100:1 to 1:1 and the addition is carried out at a temperature at or below the boiling point of the mixture; and

(b-1) stirring the solution or suspension for at least 1 hour to precipitate (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro[cyclohexane-1,1′-pyrano[3,4,b)]indol]-4-amine hydrochloride from the solution or suspension; and

(c-1) separating the precipitated salt;

or

(a-2) dissolving (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro-[cyclohexane-1,1′-pyrano[3,4,b]indol]-4-amine hydrochloride in CH 2 Cl 2 or a mixture of CH 2 Cl 2 and methanol; and

(b-2) evaporating the solvent from the solution;

or

(a-3) suspending solid (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro-[cyclohexane-1,1′-pyrano[3,4,b]indol]-4-amine hydrochloride in a solvent mixture selected from acetone/THF/water, CH 2 Cl 2 /methanol, or acetone/THF , and stirring the resulting suspension; and

(b-3) separating the suspended solid from the suspension.

6. A process according to claim 5 , wherein said solid form is a crystalline form.

7. A crystalline form of (1r,4r)-6′-fluoro-N,N-dimethyl-4-phenyl-4′,9′-dihydro-3′H-spiro[cyclohexane-1,1′-pyrano[3,4,b]indol]-4-amine hydrochloride according to claim 1 , having a CuKα radiation X-ray powder diffraction pattern comprising characteristic peaks at 10.6±0.2 (2Θ), 17.2±0.2 (2Θ), 18.6±0.2 (2Θ), 19.3±0.2 (2Θ), 26.7±0.2 (2Θ), 29.3±0.2 (2Θ) and optionally 22.2±0.2 (2Θ).

8. The crystalline form according to claim 7 , wherein the crystalline form has an endothermal event with a peak temperature at about 262-270° C., as determined by DSC.

9. The pharmaceutical composition of claim 4 , which comprises between about 0.001% by weight and about 20% by weight of the crystalline form.