Amorphization of a crystalline active pharmaceutical ingredient and thermoanalytical measurements on this glassy form

Abstract

Amorphization is nowadays a method that is frequently applied in the pharmaceutical industry. The primary aim of this study is to achieve the amorphization of clopidogrel hydrogen sulphate as an active pharmaceutical ingredient (API) with various solvents and to choose the most suitable one. A secondary aim was to determine the glass-transition temperature (T g) of this API and to classify it as a good or poor glass former. To investigate the amorphous form, differential scanning calorimetry, X-ray powder diffraction, and FT-IR analysis were applied. The melting point (T m) was 177.4 °C (450.6 K), and T g was determined to be 88.9 °C (362.1 K). The quotient T g/T m was 0.80, and this API was therefore classified as a good glass former.