Abstract
The application of isothermal microcalorimetry to the drug stability was investigated. Studies of reaction and decomposition kinetics under various conditions were deduced from the shapes of the heat flow curves, and the activation energy of the decomposition was determined from Arrhenius plots. The decomposition mechanisms of drugs in the presence of oxygen, water and an additive were also studied and the utility of this technique to evaluate the solid-state stability of drugs was demonstrated. Consequently, it is expected that the use of isothermal microcalorimetry would provide a direct, rapid and simple method of assessing drug stability.
