Research Article
Development of Modified-Release Diclofenac Sodium Capsules Using Blends of Pectin-Clay Multiparticulate Hybrid Systems as Release Retardants
Table 4
Characteristic FTIR peaks for the various materials and formulations.
| | Materials | Relevant peaks (cmā1) | Type of bond |
| | Talc | 667.82 | O-H bending | | 991.39 | Si-O stretching | | 3675.47 | O-H stretching (with no hydrogen bonding) |
| | Diclofenac | 614.90, 747.34 | C-Cl bending vibrations | | 1383.73 | O-H bending | | 1452.28, 1470.27 | C-H bending | | 1306.89 | C-N stretching | | 1505.43, 1551.42 | C=C stretching of aromatic ring | | 1573.83 | C=O stretching of carboxylic acid | | 3225.90 | O-H stretching due to carboxylic acid | | 3386.67 | N-H stretching |
| | Bentonite | 514.88 | Si-O bending vibrations | | 996.31 | Si-O stretching | | 1634.72 | O-H bending vibrations in water | | 3619.64 | O-H stretching from water | | 3695.55 | O-H stretching from silanol (Si-OH) groups |
| | Pectin | 1030.87 | C-O stretching of alcohol | | 1248.01 | C-O stretching ether bond | | 1435.89 | O-H bending of carboxylic acid | | 1605.56 | C=O stretching of carboxylic acid | | 2853.15, 2919.19 | C-H stretching (aliphatic) | | 3293.90 | O-H stretching |
| | P/T/D | 666.98 | O-H bending | | 1009.83 | Si-O stretching | | 1385.91 | O-H bending | | 1453.21 | C-H bending | | 1505.65 | C=C stretching | | 1574.69 | C=O stretching | | 3323.25 | O-H stretching due to carboxylic acid | | 3675.92 | O-H stretching (with no hydrogen bonding) |
| | P/B/D | 743.90 | C-Cl bending vibrations | | 1030.14 | C-O stretching of alcohol | | 1304.48 | C-N stretching | | 1386.53 | O-H bending | | 1450.81 | C-H bending | | 1505.74 | C=C stretching (aromatic) | | 1557.66 | C=C stretching (aromatic) | | 1574.62 | C=O stretching of carboxylic acid | | 3252.92 | O-H stretching due to carboxylic acid |
|
|
