The invention provides a methylene chloride solvate of 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine. The invention provides a method for using such solvate.
2-Methyl-4-(4-methyl-1-piperazinyl)-10H-thieno-[2,3-b][1,5]benzodiazepine, or an acid salt thereof, has pharmaceutical properties, and is of particular use in the treatment of disorders of the central nervous system. The compound has the following structure: ##STR1##
The invention relates to the methods for preparation of olanzapine polymorphic Form I. The invention also provides new mixed solvates of olanzapine, which are valuable intermediates used in the preparation of pure olanzapine polymorphic Form I.
Crystalline Form I of 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine characterised 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; infrared absorbance bands at approximately 1456, 1365, 905, 757, 662 & 604 cm.sup.-3 and having stable colour at ambient conditions of storage; and the process of its preparation comprising at least two repetitive steps of crystallization from one or more organic solvent by dissolving 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine in said solvent and allowing crystallization to occur; wherein in at least one step the solution is purified by treating with a solid adsorbent material and filtering; and wherein in the last step the crystalline material is subjected to drying.
