Thermal decomposition kinetics of the antiparkinson drug “entacapone” under isothermal and non-isothermal conditions

Abstract

The thermal decomposition kinetics of entacapone (ENT) have been investigated via thermogravimetric analysis (TGA) under non-isothermal and isothermal conditions which provide useful stability information for their processing in the pharmaceutical industry and also for predicting shelf life and suitable storage conditions. The determination of the kinetic parameters for the decomposition process under non-isothermal conditions in a nitrogen atmosphere at four heating rates (5, 10, 15, and 20 o C min-1) was performed. Kinetic parameters of the decomposition process for ENT were calculated through Friedman, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, and Li-Tang methods. This work demonstrates that the activation energies calculated from the decomposition reactions by different methods are consistent with each other. Moreover, the thermodynamic functions of the decomposition reaction were also calculated.