Solubility measurement, model evaluation and Hansen solubility parameter of ipriflavone in three binary solvents

Ipriflavone is a drug widely used in clinical treatment and prevention of osteoporosis, and it also has a certain protective effect on the nervous system. In this work, the laser dynamic method was used to measure the solubility data of IP in three binary solvents under normal pressure (temperature range: 278.15 K to 323.15 K). The results show that as both the mass fraction of positive solvents (NMP, DMF, DMAC) in the binary mixed solvents and the temperature increase, the solubility of IP increases. In addition, the Hansen solubility parameter (HSP) was used to analyze the order of solubility. The results indicated that the selected solubility parameters (Δ δ d , Δ δ p , Δ δ h , Δ δ t and Δ δ ) could explain the solubility trend well. Furthermore, the modified Apelblat equation, λH equation, NRTL model and UNIQUAC model were used to correlate the solubility data in binary mixed solvents. By calculating the deviation between the experimental data and the fitting data, it shows that the selected models have a good correlation with the solubility data of IP. Finally, the modified van’t Hoff equation was used to calculate the apparent thermodynamic properties of IP during the dissolution process . The results show that the dissolution process is always endothermic and entropy driven.