Solubility and thermodynamics of tenoxicam in (PEG-400Â +Â water) binary solvent systems at different temperatures

In this study, the solubility and thermodynamics of an anti-inflammatory drug tenoxicam (TNX) in various [polyethylene glycol-400 (PEG-400) + water] binary solvent systems was measured at temperatures T = (298.15 to 323.15) K and pressure p = 0.1 MPa. The solubilities of TNX were measured by an isothermal method and correlated with calculated ones. The mole fraction solubility of TNX was recorded highest in neat PEG-400 (3.50 × 10− 2 at T = 323.15 K) and lowest in neat water (4.13 × 10− 6 at T = 298.15 K) over the entire temperature range investigated. Thermodynamic studies on solubility of TNX indicated an endothermic, spontaneous and entropy driven dissolution behavior of TNX in all binary solvent systems investigated. The solubility experimental data of this research work could be useful in preformulation studies and formulation development of TNX.