*2.8. Di*ff*erential Scanning Calorimetry*

A differential scanning calorimeter (DSC3, Mettler Toledo, Columbus, OH, USA) was used for thermal analysis of the samples. The scans were carried out in the interval between 30 and 200 ◦C with a rate of 10 ◦C/min, followed by an isothermal step at 200 ◦C for 5 min. The amount of crystalline drug can be calculated on the basis of the melting enthalpy of the drug [48]. Here, a simplified method was used [49,50] to calculate the amount of crystalline drug in FCC-Nif and D5N20 formulations:

$$X\_c(\%) = \frac{\Delta H\_{load}}{\Delta H\_{bulk}} \times 100\tag{3}$$

where *X<sup>c</sup>* is the amount of crystalline drug, ∆*Hload* is the melting enthalpy of the drug-loaded formulation, and ∆*Hbulk* is the melting enthalpy of the drug in bulk nifedipine.
