Thermogravimetry, derivative thermogravimetry (TG, DTG), differential scann
ing calorimetry (DSC) and X ray diffraction powder patterns have been used
to study trimethoprim, sulfamethoxazole, ampicillim, tetracycline hydrochlo
ride and rifampim. The results revealed the extent of their thermal stabili
ty and also allowed interpretations concerning their thermal decompositions
in air atmosphere.