Solubility Determination and Thermodynamic Correlation for Terbinafine Hydrochloride in Several Mono-solvents from 283.15 to 323.15 K

In this paper, the solubility of terbinafine hydrochloride in 13 mono-solvents was measured in the temperature range from 283.15 K to 323.15 K at ambient pressure with the assistance of a laser-based dynamic solubility-monitoring device. It was concluded that the solubility of terbinafine hydrochloride in these mono-solvents increases with rising temperature. At 323.15 K, the molar solubility shows the following order: cyclohexanol (7.739 × 10 –2 ) > n -propyl alcohol (7.351 × 10 –2 ) > n -amyl alcohol (6.967 × 10 –2 ) > iso-butanol (6.932 × 10 –2 ) > n -butanol (6.850 × 10 –2 ) ≈ ethanol (6.778 × 10 –2 ) > isoamyl alcohol (4.926 × 10 –2 ) >1-hexanol (4.689 × 10 –2 ) > dimethyl sulfoxide (4.010 × 10 –2 ) > sec-butanol (2.878 × 10 –2 ) > isopropyl alcohol (2.452 × 10 –2 ) > isooctyl alcohol (2.211 × 10 –2 ) > acetonitrile (0.532 × 10 –2 ). Subsequently, the relationship between the solubility of terbinafine hydrochloride and temperature was correlated by six models (Apelblat, van’t Hoff, λ h, Wilson, NRTL, and Jouyban models), and the mixing thermodynamic properties of the solutions were evaluated with the solubility and the parameters simulated by the Wilson model. In addition, the solvent effect on the solubility of terbinafine hydrochloride was discussed based on the Kamlet–Abboud–Taft linear solvation energy relationships.