I have no experiences with that kind of samples particularly, but that change in the DSC trace looks more to a second order transition rather than a first order transition (like melting). Is it possible that your encapsulator form glassy phases?

Matias Ezequiel Gutierrez Suburu If you mean by glassy phase as if it were in a gel phase, so yes the lipids should b in a gel phase when the temperature is below the melting one.

No, I mean a glass phase. It is reported in some liposome system that they can present both, glass transitions and gel-to-liquid transitions on heating.

Maybe this can help you.

Article Deconvoluting Lipid Nanoparticle Structure for Messenger RNA Delivery

Matias Ezequiel Gutierrez Suburu Sorry to bother you again, but in the paper you kindly sent me, the glass transition took place way beyond the phase transition temperature. So, how a peak of glass transition can appear here without the appearance of the melting peak?

That´s depend completly on the sample, you can have a much lower gel-to-liquid transition, or even maybe you can have no gelification at all. Probably temperature dependent x-ray diffraction could give you a more detailed information about what kind of phases you have below and over 40°C.

Probably you need to do also DSC measurements with at least 3 cycles, to see, if that transition is still there or is just that is a kinetic-sink phase.

The endotherm starts after 50 oC. It is related to the moisture in the sample. Your sample undergoes a change in the heat capacity. However you need to continue heating to about 200oC. To restore the baseline.

Mahmood M. Barbooti Even if the liposome is composed of soybean lecithin, which should show a melting peak ranging from 40-60 degrees Celsius?

One more thing to mention is that the encapsulated drug should lower the melting temperature of such nano-formulation.