Table 3.
Microenvironmental pH (pHh=0 ) at the surface of ketoconazole (KTZ) free base, ketoconazole-fumaric acid (KTZ-FUM) cocrystal and ketoconazole-succinic acid (KTZ-SUC) cocrystal during dissolution testing in different buffers as determined by the slurry pH method. Each pH value is the average of two determinations
| Buffers | pH h=0 (slurry pH) | |||
|---|---|---|---|---|
| Composition | Initial pH (bulk pH) |
KTZ base | KTZ-FUM cocrystal | KTZ-SUC cocrystal |
| pH 3 phthalate buffer | 2.93 | 4.17 | 3.13 | 4.38 |
| pH 4 phthalate buffer | 3.96 | 4.38 | 4.08 | 4.19 |
| pH 5 neutralized phthalate buffer | 4.97 | 5.00 | 4.23 | 4.40 |
| pH 7 phosphate buffer | 6.97 | 7.05 | 4.53 | 4.67 |