## 3 Results
Therefore, the pure Ind decomposes (96.6%) in a temperature range of 336-397 \({}^{\circ}\)C (onset-endset temperature), while in the case of the Ind-loaded microparticles there is mass loss (95.9%) in the range of 401 \({}^{\circ}\)C and 452 \({}^{\circ}\)C. The small difference that is observed between the onset temperature in the case of Ind-SLM and bulk Compritol (97.4% loss of mass with onset temperature 403 \({}^{\circ}\)C), is almost unnoticeable when placebo-SLM without Ind are tested (96.9% loss of mass with onset temperature 403 \({}^{\circ}\)C). The same effect was also observed in the tested formulations with other active substances (e.g., CsA, Figure 3a). Figures 3 and 4 also show the hypothetical peak sizes of drug substances (CsA and Ind, respectively), determined on the basis of the conversion of the pure substance peak into the peak corresponding to its concentration in the tested formulation. As can be seen under magnification (Figures 3b and 4b), there is no drug substance peak in any of the tested drug-loaded SLM. In the next step, physical mixtures of the Ind and Compritol were tested. When the Ind is present, the physical mixtures show typical endothermic peaks corresponding to Compritol and the second peak of Ind, which is also endothermic (Figure 5). The aspect that should be noted is the shift of the Ind peak towards a lower temperature, which is the greater the lower the concentration of Ind is in the mixture. This fact is confirmed by all parameters characterizing the peak: onset, peak temperature, endset (see Figure 5). In addition to the shift, the width of the Ind peak also changes in a characteristic way, becoming narrower and sharper with increasing Ind concentration. Moreover, none of the  
Figure 4: (**a**) DSC and TG curves and (**b**) the zoom of: (**a**) F1-SLM placebo dispersion, (**b**) F10-SLM dispersion with 0.2% of Ind, (C) F11-SLM dispersion with 1% of Ind, (D) the bulk Ind and (E in figure (**a**) and E in figure (**b**)) the bulk Ind peak converted to Ind concentration in the F11-SLM with 1% of Ind. Ind peaks, regardless of their concentration in the physical mixtures, show an intensity proportional to the peak of bulk Ind, although the increase in peak intensity corresponds to the increasing concentration of the active substance in the physical mixtures. Since during SLM dispersion tests, the distribution of the drug substance is determined by shaking the microspheres with methanol [18], DSC/TG tests were also performed before and after this process. The DSC curves, after evaporation of the water-methanol mixture in the distribution test, do not differ in any way from those obtained before the dissolution of the surface-located drug substance fraction (Figure S2). Spray-dried SLM dispersions with or without the addition of auxiliary substances (e.g., PVP) were also tested (Figure 6). Figure 5: (**a**) DSC and TG curves and (**b**) the zoom of: (A) the bulk Ind, (B) the physical mixture (PM) of Compritol and Ind (1:1), (C) the physical mixture (PM) of Compritol and Ind (3:1), (D) the physical mixture (PM) of Compritol and Ind (9:1), (E) the bulk lipid Compritol. The parameters of the DSC curves characterizing the Ind peak are also listed below the graph. Figure 6: (**a**) DSC and TG curves and (**b**) the zoom of: (A) F10-SLM dispersion with Compritol and 0.2% of Ind, (B) F10-SLM after spray drying, (C) F10-SLM after spray drying with PVP, (D) F10-SLM after spray drying with Mx, (E) the bulk PVP and (F) the bulk Mx. The parameters of the DSC curves characterizing the lipid peak are also listed below the graph. The obtained thermograms indicate that there is no significant effect of the drying process on the properties of the dried formulations with Compritol (regardless of the tested active substance: the results of SLM with Ind are shown in Figure 6, and the microspheres with CsA and SPIR have been described previously [19]).