Sulphamethoxydiazine crystal forms

Abstract

Methods of preparation of three polymorphs, two solvates and an amorphous modification of sulphamethoxydiazine are described. Infrared spectroscopy and X-ray diffraction data are given for the characterization of the various forms. The interconversion of these forms under various conditions of heating, suspension in water and grinding is studied. The dissolution behaviour of the different forms is also discussed. All forms on heating to 150° change to the same form and on suspension in water change to another water-stable form.