Table 7.
Effect of loading method and drug physicochemical properties on the drug ionization. Values in brackets indicate the standard deviation from reported mean (n = 3; * Significantly different from corresponding unmedicated hydrogels; p < 0.05).
| Sample | Drug concentration (% w/w) | Apparent pH | Drug ionization in film (%) | Drug ionization in phosphate buffer pH 7.2 (%) |
|---|---|---|---|---|
| Unmedicated | - | 5.61 (±0.01) | - | - |
| Unmedicated (EtOH) | - | 5.61 (±0.00) | - | - |
| Post-loaded LID | 9.75 | 5.80 (±0.00) * | 99.14 | 82.05 |
| Post-loaded DIC | 20.68 | 6.71 (±0.00) * | 0.27 | 0.09 |
| Post-loaded IBU | 59.09 | 4.66 (±0.01) * | - | - |
| In situ Loaded LID | 9.93 | 6.34 (±0.01) * | 97.07 | 82.05 |
| In situ Loaded DIC | 20.26 | 6.75 (±0.01) * | 0.25 | 0.09 |