Polymorphism, Tripalmitin

Sample

Tripalmitin

Application

Inactive ingredient

Conditions

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

Interpretation

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.

Evaluation

Conclusion

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}