Solubility and Thermodynamic Properties of Clotrimazole in 16 Organic Solvents at Temperature of 283.15 to 323.15 K

Abstract

In this paper, the solubility of clotrimazole, an antifungal drug, in 10 alcohols (n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, n-pentanol, iso-pentanol, n-hexanol, n-heptanol, and n-octanol) and 6 esters (methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, isopropyl acetate, and methyl propionate) was experimentally determined using a laser dynamic solubility-monitoring device in a temperature range of 283.15 to 323.15 K at atmospheric pressure. The functions of solubility versus temperature were regressed using three semi-empirical models (modified Apelblat, three-parameter van’t Hoff, and λh) and two activity coefficient models (Wilson and NRTL). The results show that all the five models can be used to correlate the solubility of clotrimazole with temperature in these solvents satisfactorily. Furthermore, the thermodynamic mixing properties (ΔmixG, ΔmixH, ΔmixS, ln(γ1∞), and H1E, ∞) were evaluated using the measured solubility values and Wilson model parameters.