At first, physical-chemical properties of raw material were characterized to investigate changing in drug solid state after formulation. ATR-FTIR was used to assess main peaks related to PVA, PHEA, and ibuprofen sodium, respectively. Notably, this method allows identification of creation of hydrogen bonding that might indicate the formation of new bonds between drug and polymers (35). Figure 1 presents ATR-FTIR spectra for raw material and peak assignation was reported in Table II. Peak assignation was coherent with literature, and ibuprofen sodium spectra resulted in being consistent with pure drug spectra in the crystalline form (36–38).
Fig. 1 ATR-FTIR spectra of raw materials PVA, PHEA, and ibuprofen sodium
Table II Peak Assignation for Each Raw Material PVA, PHEA, and Ibuprofen Sodium. Data Are Coherent with Literature Findings (36–38)
Raw material Peaks Assignation
PVA 3290 cm−1 Stretching O–H group
2939 cm−1 Asymmetric stretching C–H group
1732 cm−1 Stretching C=O
1567 cm−1 Stretching C=C
1421 cm−1 Symmetric bending CH2 group
PHEA 3276 cm−1 Stretching O–H bond
2938 cm−1 Aliphatic stretching C–H group
1633 cm−1 Stretching C=O group
1525 cm−1 Vibrations N–H group
1427 cm−1 Aliphatic bending C–H group
1362 cm−1 Bending O–H group
1056 cm−1 Ester group
Ibuprofen sodium 2951 cm−1 Asymmetric stretching CH3 group
1698 cm−1 Stretching C=O group
1545 cm−1 Stretching vibrations C=C
1251 cm−1 C–O stretching
748 cm−1 Vibration CH2 group
PVA polyvinyl alcohol, PHEA poly-N-hydroxyethyl-aspartamide