Table 3.
Enthalpies of solution in phosphate buffer (pH8) and methanol at 25°C, solubility, enthalpies of solvation of Atorvastatin and its solvates
| Solubility in phosphate buffer pH7 (mg/ml) (SsolpH7 ) |
Molar enthalpy of solution in its own solvent (kJ mol-1) |
Enthalpy of solvation ΔsolvH (kJ mol−1) |
Molar enthalpy of solution (kJ mol-1) |
|||
|---|---|---|---|---|---|---|
| Solvates (ΔsolH2) | Atorvastatin Calcium (ATC) (ΔsolH1) | Phosphate buffer (pH8) ΔsolH | Methanol ΔsolH (methanol) | |||
|
Atorvastatin Calcium (ATC) |
0.166 |
− |
− |
− |
21.89 |
19.11 |
|
Solvate- I (ATC + 0.5 Isopropyl alcohol)) |
0.374 |
−24.45 |
−13.52 |
−10.93 |
2.51 |
1.15 |
|
Solvate- II (ATC + THF) |
0.192 |
−11.32 |
10.85 |
−22.17 |
14.31 |
9.95 |
|
Solvate- III (ATC + Ethanol) |
0.292 |
−7.61 |
32.06 |
35.55 |
5.46 |
3.05 |
|
Solvate- IV (ATC + 0.5 t-butanol) |
0.225 |
3.16 |
34.85 |
−31.69 |
11.50 |
5.45 |
|
Solvate- V (ATC + methanol) |
0.341 |
2.12 |
16.35 |
−19.98 |
3.85 |
2.12 |
|
Solvate-VI (ATC + 1 Acetone +0.5 Ethanol) |
0.245 |
−10.80 |
41.20 |
−48.40 |
8.35 |
5.1 |
|
Solvate-VII (ATC + 0.5 Ethanol + Water) |
0.185 |
−4.25 |
112.49 |
−116.74 |
16.98 |
12.7 |
| Solvate- VIII (ATC + 1- butanol) | 0.387 | −4.6 | 13.36 | −17.96 | 1.17 | 0.57 |