## 3 Results and Discussion
### Simultaneous Thermal Analysis (TGA-DSC)  
The thermal behavior of the films based on starch, chitosan, maltodextrin, and the active pharmaceutical ingredient was analyzed using TGA and DSC, as evidenced in Figures 5 and 6, respectively. For the TGA curves and the respective derivatives (DTG) obtained for each polymer mentioned above, two very similar stages of mass loss are identified. The first stage occurs around 100 \({}^{\circ}\)C and is attributed to the loss of water and volatile components. The second stage, observed around 300 \({}^{\circ}\)C, corresponds to the degradation and decomposition of the compounds. Among the analyzed samples, TPS exhibits the lowest thermal stability, as evidenced by continuous weight loss with a maximum slope between 25 \({}^{\circ}\)C and 270 \({}^{\circ}\)C. Thus, the TGA thermogram of the TPS film demonstrated a weight loss in three stages. In the first stage, the loss of moisture was observed at a temperature below 100 \({}^{\circ}\)C. The second stage indicated the degradation of the plasticizer between 250 \({}^{\circ}\)C and 275 \({}^{\circ}\)C. The third stage is related to the decomposition of the polymeric material between 300 \({}^{\circ}\)C and 350 \({}^{\circ}\)C. The above is corroborated by the DSC curve through the endothermic peaks. As for the active ingredient, a moisture loss of -15% is observed in the TGA curve, followed by excellent stability in which the mass content is not altered. The initial degradation temperature (T\({}_{0}\)) is observed at 272 \({}^{\circ}\)C, and it ends at 354 \({}^{\circ}\)C (final degradation temperature, T\({}_{\text{f}}\)). The thermal behavior of the ternary TPS-CH-M mixture suggests the presence of weak intermolecular interactions. In polymeric systems, high viscosity in physical mixtures, along with steric hindrance caused by coiled polymer chains, limits the extent of interaction between components [43]. The TPS-CH-M blend presented a maximum degradation temperature equal to 290 \({}^{\circ}\)C, while the TPS-CH-M-A blend decreased its value significantly by 20 \({}^{\circ}\)C. The incorporation of the API in a solid state is distributed and inserted between the polymer chains, limiting the interactions and blocking the dissipation of thermal energy [44]. DSC provides insight into the thermal transitions characteristic of different materials. Neat starch exhibits a second-order transition (see  
Figure 4: XRD patterns of TPS-CH-M and TPS-CH-M-A. broad band between 50 \({}^{\circ}\)C and 65 \({}^{\circ}\)C). On the other hand, starch in the presence of plasticizers and under thermomechanical process conditions presents an increase in heat absorption due to the change in the polymeric network. This process, known as gelatinization, is highly dependent on plasticizer content. For TPS, a transition in heat flow is observed beginning at approximately 50 \({}^{\circ}\)C and reaching an endothermic minimum at 87.9 \({}^{\circ}\)C. This process concludes around 150 \({}^{\circ}\)C. Similarly, maltodextrin presents a less pronounced endothermic event near 100 \({}^{\circ}\)C. The glass transition of chitosan occurs at 67.4 \({}^{\circ}\)C within an endothermic band extending up to approximately 100 \({}^{\circ}\)C, which is associated with the evaporation of solvents, such as water and acetic acid. The TPS-CH and TPS-CH-M mixtures undergo complete gelatinization due to extensive intermolecular interactions between the polymeric components. These blends demonstrate enhanced thermal stability, as corroborated by TGA, which reveals an increase in degradation temperatures. Additionally, the thermal transitions are delayed, with a glass transition temperature (T\({}_{\text{g}}\)) of 124.7 \({}^{\circ}\)C and a melting temperature (T\({}_{\text{m}}\)) of 156.8 \({}^{\circ}\)C. These results are not comparable to those obtained in the molten state or through reactive extrusion, emphasizing the significance of processing variables during mixing [45].