Abstract
Thermogravimetry (TG) and differential scanning calorimetry (DSC) are useful techniques that have been successfully applied in the pharmaceutical industry to reveal important information regarding the physicochemical properties of drugs and excipient molecules, such as polymorphism, stability, purity, formulation compatibility, among others. AMI presents a thermal stability of up to 431 K and a fusion onset temperature of 432 K. The drug has proven to be incompatible with magnesium stearate, eskis red pigment, and yellow iron oxide. In the present study, this drug presented degradation upon undergoing basic hydrolysis and oxidation; the degradation product produced under basic hydrolysis is 2-butyl-3-benzofuranyl-3,4-dihydroxy-5-iodophenylketone. Assessing the degradation kinetics, the drug presented a shelf life (t90) of 43 years, while a pharmaceutical formulation showed a t90 of 1.7 years, which is consistent with commonly understood incompatibilities in pharmaceutical formulations.
Acknowledgements
The authors wish to thank FAPES, CNPq, and FAPEMIG for their financial support and Laboratório Teuto Brasileiro for their donation of raw materials.
Declaration of interest
Financial support for this research was provided by FAPES, CNPq, and FAPEMIG.