Differential Scanning Calorimetry (DSC) Profiles of Polyols

Pharmaceutically applicable polyols are represented with different chemical compounds and thermal properties. Thermal properties, such as melting temperature (onset, peak, and offset) and recrystallisation temperature are very important characteristics for the formulation, processing, and physical/chemical stability of compounded samples or products. One of the most reliable ways for the characterization of thermal properties (melting and recrystallisation temperature) is Differential Scanning Calorimetry (DSC).
Thus, project-related samples of commercially available polyols were characterised using a Chip DSC 100 (Linseis; Selb, Germany). The representative individual DSC profiles were organised in a dataset in the form of an Excel spreadsheet. To simplify the perception of data, on the separate Excel spreadsheet, DSC profiles are visualised in graphical form (heat flow vs. temperature), and the summary table of characteristic thermal events (if applicable) was added.
To investigate the thermal properties of sucrose, dextrin, inulin, xylitol, sorbitol, isomalt, mannitol, oligofructose, polyethylene glycol, caffeine, and α,α-trehalose dihydrate, the study of commercially available grades was conducted. For this purpose, a Chip DSC 100 (Linseis; Selb, Germany) was used. Each sample was weighed (3 – 5 mg) into individually weighed aluminium DSC pans. The sample chamber with the sample present was purged each time with Nitrogen gas (200 sccm/min) for 5 minutes prior to the analysis. Each sample was analysed at a heating rate of 10 ℃/min [1] from 30 ℃ to approximately 20 ℃ above each respective sample’s melting point (but 10 – 20 ℃ below each respective sample’s degradation point). The samples were then cooled down at a rate of 10°C/min to 30 ℃, and heated once again as previously described. Throughout the whole duration of the analyses, a constant flow of Nitrogen gas (20 sccm/min) was applied. For the analysis of caffeine, crimped aluminium DSC pans were used with individually weighed lids.
The data was processed with Universal V4.5A software (Linseis; selb, Germany), and the dataset in the form of an Excel spreadsheet was composed of the representative individual DSC profiles of specific polyol grades: heat flow (mW) vs. temperature (℃).
To simplify the reusing of data, on the separate Excel spreadsheet, all DSC profiles were presented on the same graph (heat flow vs. temperature), and the table of characteristic thermal events (if applicable) for each sample was composed/presented too.
The samples after DSC analysis are stored in a controlled environment (25 ℃/60 %rh) for future (stability) investigations.