Thermal stability of anti-rheumatic pharmaceutical drugs parecoxib sodium and valdecoxib

Thermal analysis of antirheumatic drugs, parecoxib sodium (PCX) and valdecoxib (VCX) was achieved. Thermogravimetry (TG), derivative thermogravimetry (DTG), and differential thermal analysis (DTA) were used through the work. The results led to thermal stability data, and also to the determination of kinetic parameters such as activation energy and frequency factor. The differential scanning calorimetry (DSC) was suitable for the purity determination of the compounds. The simplicity, speed, and low operational costs of thermal analysis justify its application in the quality control of pharmaceutical drugs.