Spectrum 65

Fourier transform infrared spectroscopy (FTIR) was carried out using a Perkin Elmer Spectrum 65 and used to confirm both the N-succinylation of the chitosan and its functionalisation with CB; whereas both morphology and structure of NSC and NSC-CB were investigated using a Zeiss Σigma™ field emission gun scanning transmission electron microscope (SEM, FEG-STEM). The size of the beads was evaluated using a dynamic light scattering system (DLS) from Zetasizer ZS90 (Malvern Instruments Ltd., UK).

The structural characterization of F6 formulation and its excipients was assessed by FTIR-ATR, DSC, TEM, and FE-SEM techniques.
In the ATR-FTIR technique, the spectra were recorded with FTIR spectrophotometer with ATR cell (BRUKER IFS 66 v/S or Perkin Elmer SPECTRUM 65) equipment. The spectra were operated in reflectance mode in the range of 4500-500 cm⁻¹, with a 2 cm⁻¹ resolution. DSC measurements used a cooled TA Q20 calorimeter system. The samples (5 mg) were positioned in aluminum pans and the thermal transitions were assessed in the temperature range from 0 to 100°C, at a heating rate of 10°C/min, under nitrogen flow.
For FE-SEM, the sample was adhered to a stub. After, the stubs were sputtered with gold bath for 120 s at 30 kV. The nanoparticles were visualized in a field JEOL electron scanning microscope (model JSM 5800LV), operating under a variable voltage from 0.3 to 30 kV, with tungsten filament, through the SemAfore 5.21 image capture system software. For TEM, the sample was added to a copper grid. Then, the sample dried with filter paper. The (2% w/w) uranyl acetate was added to provide contrast, and the excess of liquid was removed. Subsequently, deionized water was dropped to the grid, and the excess was removed. The nanoparticles were visualized in a Zeiss–LEO 906 TEM, operating at 60 kV and equipped with an Olympus iTEM CCD camera and image capture software.

The FTIR spectra of the glue samples were recorded using a Spectrum 65 (Perkin Elmer, Waltham, MA, USA) infrared spectrometer using the Attenuated Total Reflectance (ATR) technique. The glue samples were measured from 4000 cm⁻¹ to 600 cm⁻¹ with a 4 cm⁻¹ resolution. The spectra were averaged over 32 scans.

The XRD measurements were performed with a Bruker D8 Advance diffractometer (CuKα, λ = 1.5406 Å) in the range of 2θ = 3–35° with 0.02° step and 0.1 s step time for perovskite films. The morphology of the films was investigated using Carl Zeiss NVision 40 field-emission scanning electron microscope with EDX detector (Oxford instruments). For cross-section observations, the samples were coated with an ultrathin (<10 nm) layer of Cr to avoid sample charging. The IR spectra of the as-grown Phase-1 crystals were recorded in the attenuated total reflection mode in spectral range 400–4000 cm⁻¹ with a resolution of 4 cm⁻¹ on IR Fourier spectrometer Perkin Elmer Spectrum 65. For each spectrum as well as for the background, 128 scans were averaged.

ATR-IR measurements were performed on a Perkin Elmer, Spectrum 65 (Waltham, MA, USA) FTIR spectrometer, equipped with a single reflection diamond crystal at room temperature. ATR-IR spectra were recorded in a range from 4000 to 600 cm⁻¹ at 64 scans per spectrum with a resolution of 4 cm⁻¹.

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis: Infrared analyses (ATR-FTIR) were performed of the PCL nanocapsules with and without LDC + PLC. LDC and PLC were also analyzed in their free forms. The spectra were obtained using FTIR spectrophotometers (Bruker IFS 66 v/S or Perkin Elmer Spectrum 65) fitted with ATR cells and operated in reflectance mode, in the range 4500–500 cm⁻¹, with steps of 2 cm⁻¹.
Differential scanning calorimetry (DSC) analysis: The same formulations were also submitted to DSC measurements performed using a TA Q20 calorimeter equipped with a cooling system. After calibrating the equipment with indium, 5 mg portions of the samples were placed in aluminum pans and the thermal profiles were obtained in the temperature range from 0 to 250 °C, at a heating rate of 10 °C/min, under a flow of nitrogen.