Thermal decomposition of some diuretic agents

Thermogravimetry-derivativc thermogravimetry and differential scanning calorimetry were used to study the thermal behaviour of furosemide, hydrochlorothiazide, spironolactone, and amiloride hydrochloride. The results revealed the extents of their thermal stability and also permitted interpretations concerning their thermal decompositions.The authors thank FAPESP (Proc. 90/2932-4) and CNPq for financial support, and Hoechst of Brazil, Prodome Química e Farmaceutica Ltda, Campinas, Brazil, and Biolab. Industrias Farmaceuticas, Brazil, for supplying the diuretic agents used in this study.