Monitoring the polymorphic transformation on the surface of carbamazepine tablets generated by heating using near-infrared chemical imaging and chemometric methodologies

• Polymorphic transformation of carbamazepine in pharmaceutical formulations
• Heating at 140 °C for 7 h, with data acquisition in each hour
• NIR-CI in conjunction with chemometric methodologies
• MCR and PARAFAC were able to identify and quantify the polymorphic forms.
• Possibility of dynamic study of the system using NIR chemical imaging

This work presents the monitoring of the polymorphic transformation of carbamazepine (form III to form I) in pharmaceutical formulations as tablets, generated by heating at a temperature of 140 °C for 7 h, with data acquisition in each hour. Near infrared chemical imaging in conjunction with chemometric procedures was used to evaluate the change on the distribution of each polymorph in the tablet surface. The concentration distribution maps of polymorphic forms I and III of carbamazepine in the tablet were estimated by matrix-augmented multivariate curve resolution (MCR) and parallel factor analysis (PARAFAC). The concentration profile as a function of time under heating allowed a dynamic study of the system. The results show that MCR was able to provide information about the polymorphic transformation of carbamazepine tablets in the dynamic process, generating distribution maps for each acquisition time. PARAFAC provided global information about the system, but it was not able to completely resolve the spectral components.