Table 1.
Ribociclib solubility vs. pH
| pH | Buffer | Solubility, mg/mL | Bile salt concentration |
|---|---|---|---|
| 2.0 | HCl/KCl | >2.4a | — |
| 4.5 | Acetate | >2.4a | — |
| 6.8 | Phosphate | 0.8 | — |
| 7.5 | Phosphate | 0.3 | — |
| 6.5 | FaSSiF‐V1b | >2.4 | 3 mM |
| 5.0 | FeSSiF‐V1c | >2.2 | 15 mM |
a
Equates to 600 mg (clinical dose) of free base in 250 mL solution (volume represents typical quantity of water taken during drug administration).
b
FaSSiF = Fasted‐state simulated intestinal fluid (pH = 6.5, sodium taurocholate 3 mM, lecithin 0.75 mM, sodium chloride 105.9 mM, monobasic sodium phosphate 28.4 nM, sodium hydroxide 8.7 mM, pancreatin 10 mg/mL).
c
FeSSiF = Fed‐state simulated intestinal fluid (pH = 5.0, sodium taurocholate 15 nM, lecithin 3.75 nM, sodium chloride 203.2 nM, acetic acid 144.1 mM, sodium hydroxide 101 mM, pancreatin 40 mg/mL).