Patent ID: 6906062

Claim:
Crystalline Form I of 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine characterized by x-ray powder diffraction peaks at approximately 9.94, 8.53, 8.19, 6.86, 6.35, 5.47, 4.83, 4.71, 4.53, 4.22, 4.08, 3.82, 3.75, 3.69, 3.50, 3.34, 3.11, 2.94, 2.82, 2.76, 2.59, 2.34, 2.03, 1.92 d (interplanar spacing) values and having stable colour upon storage at ambient conditions.