Physico-chemical characterisation of different solid forms of spironolactone

Spironolactone is a steroidal diuretic showing incomplete oral behaviour be cause of its low solubility and slow dissolution rate. Four solid forms wer e obtained by recrystallisation of a commercial sample from different solve nts (acetone, methanol, ethyl acetate). These samples have been characteris ed by Fourier transform infrared (FT-IR) Spectroscopy, X-ray powder diffrac tion, thermogravimetric analysis coupled with FT-IR spectroscopy (TG/FT-IR) and differential scanning calorimetry (DSC). The aim of the work is establ ish evidence for differences, if any, between the forms and, possibly, to u nderstand their nature. A careful analysis of the collected data makes it p ossible to rule out the presence of any solvate and to distinguish three di fferent polymorphs. (C) 1999 Elsevier Science B.V. All rights reserved.