Measurement and Modeling the Volumetric Properties of Aqueous Solutions of Guaifenesin Drug in the Presence of NaCl

Guaifenesin(GG), also known as guaiphenesin or glyceryl guaiacolate, is an expectorant medication sold over the counter and usually taken by mouth to assist the bringing up (expectoration) of phlegm from the airways in acute respiratory tract infections[1]. Study on the thermodynamic and physicochemical properties of each component of medicines before the complexity of the systems can provide useful informations[2]. Therefore, in this work, density data of GG drug in water and aqueous solutions of NaCl have been measured within NaCl molality range of (0.05, 0.1, and 0.15) mol kg-1 at T = (298.15, 308.15 and 318.15) K. The apparent molar volume have been calculated from density values with equation of in which m is molality of solution, M is the molar mass of the GG drug, d and d0 are densities of solution and solvent, respectively. The behaviours of apparent molar volume for aqueous solution of GG and also GG + NaCl indicates a decrease in the interaction of GGH2O, as well as GG-NaCl-H2O with temperature increasing.The values for the aqueous solutions containing drug and NaCl are higher than those of the aqueous solutions containing the drug and increase with increasing the concentration of salt. This behaviour suggests that the size of the GG molecule increases due to the decrease in the interaction of GG with water in the presence of salt. The apparent molar volume values of the considered solutions have successfully been modelled via the Redlich–Meyer type equation[3] in the dilute region.