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 |