Solubility analysis of 18 active pharmaceutical ingredients and intermediates in the non-polar solvents dioxane, toluene and cyclopentyl methyl ether

The temperature dependent solubility of 18 organic compounds, which some are active pharmaceutical ingredients, was measured in 1,4-dioxane, toluene and cyclopentyl methyl ether over a range between 0 70 °C using turbidity method. the studied compounds three solvents increases with all binary solute-solvent systems, exhibit higher 1,4-dioxane than ether. non-ideal behaviour systems evaluated terms activity coefficient. All presented positive deviation from ideal solution, while both negative deviations were observed for model other two apolar solvents. From coefficient, number thermodynamic models including van’t Hoff, Apelblat, ?h, Margules, van Laar, Wilson, Non-Randomness Two Liquids (NRTL) used correlation experimental data. NRTL Hoff equations present closer overall correlations, Margules ?h show >5 % several solvent systems. mixing properties further analyzed by ‘t Wilson better understanding solution behaviour. analysis revealed apparent where counteracting non-ideality effects cancel each other’s.