To determine the physical state of the PGZ-NPs and their interactions with any compound of the formulation, studies by Differential Scanning Calorimetry (DSC), X-ray spectroscopy, and Fourier Transform Infrared (FTIR) were performed before and after the spray drying process.
DSC analysis was performed using a DSC 823e System (Mettler Toledo, Barcelona, Spain). The temperature was calibrated by the melting transition point of indium (purity ≥ 99.95%; Fluka, Switzerland) prior to sample analysis. The DSC measurements used a heating ramp from 30 to 240 °C at 10 °C/min in a nitrogen atmosphere. Data were evaluated using the Mettler STARe V 9.01 dB software (Mettler Toledo, Barcelona, Spain).
To determine the state—crystalline or amorphous—of the samples, X-ray spectral measurements were performed using Siemens D500 system (Karlsruher, Germany). X-ray powder diffractograms were recorded using a Cu Kα2 radiation (45 kV, 40 mA, λ = 1.544 Å) in the range (2θ) from 2° to 60° with a step size of 0.026° and the measuring time was 200 s per step.
FTIR spectra were achieved using a Thermo Scientific Nicolet iZ10 with an ATR diamond and DTGS detector (Thermo Fischer Scientific, Waltham, MA, USA). The scanning range used was 500–4000 cm−1.
DSC analysis was performed using a DSC 823e System (Mettler Toledo, Barcelona, Spain). The temperature was calibrated by the melting transition point of indium (purity ≥ 99.95%; Fluka, Switzerland) prior to sample analysis. The DSC measurements used a heating ramp from 30 to 240 °C at 10 °C/min in a nitrogen atmosphere. Data were evaluated using the Mettler STARe V 9.01 dB software (Mettler Toledo, Barcelona, Spain).
To determine the state—crystalline or amorphous—of the samples, X-ray spectral measurements were performed using Siemens D500 system (Karlsruher, Germany). X-ray powder diffractograms were recorded using a Cu Kα2 radiation (45 kV, 40 mA, λ = 1.544 Å) in the range (2θ) from 2° to 60° with a step size of 0.026° and the measuring time was 200 s per step.
FTIR spectra were achieved using a Thermo Scientific Nicolet iZ10 with an ATR diamond and DTGS detector (Thermo Fischer Scientific, Waltham, MA, USA). The scanning range used was 500–4000 cm−1.