Solid state modifications of drospirenone

Abstract

This manuscript presents a structural, thermal and spectroscopic characterization of two different solid state forms of drospirenone (C24 H30 O3), a crystalline phase and an amorphous one. The molecule contains three fused six-membered rings and two five-membered rings; none of them is planar in character. An intra-molecular hydrogen bond was observed in the crystalline phase. Although the melting point is 202(1) °C, only very weak interactions could be considered responsible for the packing in the crystal. The amorphous phase was obtained from molten material and was found five times more soluble than the crystalline one. Infrared and Raman spectra for both phases were recorded and the vibrational properties were calculated using the GAUSSIAN 03 software package; overall agreement between calculations and experiment was obtained.