Tripalmitin
Inactive ingredient
Measuring cell: DSC820
Pan: Aluminum 40 µl, hermetically sealed
Sample preparation: As received
DSC measurement: Heating from 30 °C to 250 °C at 10 K/min
Atmosphere: Nitrogen, 80 cm3/min
The first heating run shows that tripalmitin as received is in the stable form. On cooling, a metastable modification crystallizes out, whose melting point lies lower than that of the thermodynamically stable form. In the second heating run, the liquid phase formed on melting crystallizes on nuclei of the stable modification. A determination of the heat of fusion of the metastable form is uncertain (and is put in brackets), since the crystallization of the stable form occurs at the same time as the melting of the metastable form. The lower onset temperature and the slightly lower heat of fusion are caused by incomplete crystallization of the stable form.
Onset, °C | ΔH, J/g | Onset, °C | ΔH, J/g | |
---|---|---|---|---|
Heating run 1 | - | - | 67.2 | 196.7 |
Heating run 2 | 43.8 | 113.9 | - | - |
Heating run 3 | 46.7 | (66.8) | 65.4 | 190.6 |
The DSC is an excellent technique for the detection of polymorphic modifications.
Polymorphism, Tripalmitin | Thermal Analysis Application No. HB833 | Application published in METTLER TOLEDO TA Application Handbook Pharmaceuticals