The thermal decomposition of antituberculous, local anaesthetic and ca
lcium salts of organic acids used as the drugs has been studied by dif
ferential thermal and thermogravimetric techniques. General characteri
stics of their thermal decomposition has been made. The effect of samp
le size over the range 20-200 mg and heating rate over the range 3-15
deg.min(-1) on the thermal degradation has been investigated. The valu
es of the kinetic parameters has been also determined.