Patent ID: 7145036

Claim:
A highly pure (R,R)-formoterol L-tartrate composition obtained by a process comprising crystallizing a first polymorph (C) of (R,R)-formoterol L-tartrate from aqueous isopropyl alcohol, said first polymorph having peaks at the diffraction degrees with the intensity shown below in an X-ray powder diffraction pattern: Peak number 2-Theta Intensity 1 6.4 100.0 2 9.0 14.4 3 11.1 14.8 4 12.4 13.9 5 12.9 19.7 6 13.5 19.5 7 14.0 15.1 8 15.0 19.7 9 15.4 16.9 10 15.7 18.1 11 16.3 12.8 12 17.5 64.9 13 19.4 47.3 14 19.9 44.8 15 21.3 29.3 16 22.3 31.5 17 22.9 35.8 18 24.1 80.0 19 24.7 17.6 20 25.5 11.3 21 26.0 15.6 22 26.8 9.1 23 27.4 8.5 24 28.4 10.8 25 29.0 8.5 26 30.5 8.1 27 32.7 10.9 28 34.2 7.9 29 35.7 9.3 30 36.4 6.6 31 37.3 7.9 32 37.8 9.1 33 39.3 10.0 34 39.6 11.4 35 41.1 5.7 36 42.3 4.7.