Patent ID: 7501515

Claim:
A polymorphic Form-III of 17-β-(N-ter. butyl carbamoyl)-4-aza-5-α-androst-1-en-3-one having the formula, which is characterized by the following data: DSC: exhibits a melting endotherm with a peak temperature of about 262° C. and preceded by another minor endotherm at about 245° C. and an exotherm at about 253° C.; XRD (2θ): 5.32, 10.70, 13.64, 14.96, 15.86, 16.12, 16.56, 17.20, 18.22, 19.60, and 23.04; FT-IR (In KBr): 3427, 3233, 2931, 1679, 1600, 1501,1451 and 820 cm −1 .