Patent ID: 8049031

Claim:
Fesoterodine fumarate in crystalline form I, characterized in that it has a powder X-ray diffraction spectrum having the following peaks (±0.20° 2 theta): 8.95; 10.55; 11.64; 11.94; 13.02; 13.32; 15.01; 16.42; 17.74; 18.11; 19.14; 19.59; 20.16; 20.99; 22.20; 23.25; 24.16; 25.08; 26.13; 28.35; 32.66° (2 theta); it has a DSC profile measured with a heating rate of 10° C./min that shows an endothermal peak with Peak onset at 105.95° C.±0.1° C., Peak at 109.17° C.±0.1° C. and it has an IR spectrum that shows the following peaks (±2 cm −1 ): 3473; 1757; 1700; 1558; 1234; 1213; 1176; 1156; 1127; 1097; 1018; 982; 907; 794;703 cm −1 .