Table III.
Frequencies of Selected Raman Bands for the Crystalline, Amorphous, and Formulated Forms of CBZ
| Raman frequency (cm−1) | |||||||
|---|---|---|---|---|---|---|---|
| Raman band assignment (59) | Crystalline CBZ | Amorphous CBZ | CBZ-AFF100 | CBZ-AFF4000 | CBZ-EPO | CBZ-VA 64 | CBZ-Soluplus |
| Lattice vibration | 374.4 | 369.3 | 364.4 | 364.8 | 369.7 | 365.2 | 365.4 |
| C–N–C stretch | 723.4 | 718.1 | 718.1 | 718.2 | 719.3 | 720.2 | 719.4 |
| C–C ring stretch/C-N-C asymmetric stretch | 1160.4 | 1158.4 | 1154.8 | 1154.8 | 1154.2 | 1154.8 | 1154.9 |
| C–N stretch (amide III) | 1222.0 | 1218.4 | 1219.4 | 1219.4 | 1217.8 | 1219.6 | 1219.4 |
| C=C ring stretch | 1565.6 | 1562.8 | 1563.9 | 1563.8 | 1561.8 | 1563.4 | 1563.9 |
| Mean difference from crystalline CBZ | −3.7 | −5.0 | −5.0 | −4.6 | −4.5 | −4.6 | |
For each formulation, the Raman spectrum of the neat polymer was subtracted from the Raman spectrum of the 30% CBZ/polymer formulation
CBZ carbamazepine, EPO EUDRAGIT® E PO