Table 4.
FTIR band assignment of various spray-dried formulations
| Band assignment | Wavenumber (cm−1) | |||
|---|---|---|---|---|
| Colistin | Colistin: Meropenem_1:1 | Meropenem | ||
| Colistin | C-H stretching | 2956.3 | NA | |
| Amide I C=O stretching | 1645.0 | 1650.8 | ||
| Amide II N-H bending | 1525.4 | 1531.2 | ||
| C-N stretching | 1068.4 | 1074.1 | ||
| Meropenem | Carboxyl O-H stretching | NA | 2958.2 | |
| β-lactam C=O stretching | 1758.7 | 1756.8 | ||
| Carboxyl C=O stretching | 1650.8 | 1658.5 | ||
| Dimethylcarbamoyl C-N stretching | 1380.8 | 1373.1 | ||
| β-lactam C-N stretching | 1255.4 | 1253.5 | ||
| Pyrrolidine C-N stretching | 1139.7 1074.1 |
1145.5 | ||
| 1095.4 | ||||
| 1072.2 | ||||
| Hydroxyethyl and β-lactam C-H wagging and twisting | 1074.1 | 1051.0 | ||