Polymorphs of an active pharmaceutical ingredient

A crystalline Form I of Febuxostat having an X-ray powder diffraction pattern as measured using CuKα radiation comprising peaks at 2-theta angles of 6.6±0.2°, 12.8±0.2°, 24.5±0.2, 25.8±0.2°, 26.6±0.2°, and

• being characterized by an IR spectrum comprising absorption bands at wavenumbers of about 2960±2 cm−1, 2874±2 cm−1, 2535±2 cm−1, 2229±2 cm−1, 1673±2 cm−1, 1605±2 cm−1, 1509±2 cm−1, 1422±2 cm−1, 1368±2 cm−1, 1323±2 cm−1, 1274±2 cm−1, 1166±2 cm−1, 1116±2 cm−1, 1045±2 cm−1, 1013±2 cm−1, 911±2 cm−1, 820±2 cm−1, 763±2 cm−1 and 725±2 cm−1.