Thermodynamic investigation of the effect of octanol–water mutual miscibility on the partitioning and solubility of some guanine derivatives

Abstract

The effects of mutual saturation of octanol and water on solute partitioning and solubility have been examined. The partition coefficients and solubilities in octanol, water and mutually saturated octanol-water phases were determined for eight antivirus guanine derivatives. Using the Solubility data, enthalpies of fusion (A,,,H) and melting temperatures (Tm), determined by differential scanning calorimetry (DSC), the activity coefficients of the solutes in the aqueous and organic phases were calculated. From these results the intermolecular interactions among the solute and solvent molecules in the aqueous and octanol phases were estimated. It has been shown that the mutual saturation of the octanol and aqueous phases plays an important role in the partitioning of semipoiar substances, such as guanine derivatives.

Thermodynamic study of the solubility of triclocarban in ethanol + propylene glycol mixtures

“…In a first approach the term (V 2 f 1 2 /RT ) T,P may be considered approximately constant at the same temperature, and then g 2 depends almost exclusively on w 11, w 22 and w 12 . 12 While the term w 12 term favors the solution process, both w 11 and w 22 terms are unfavorable for solubility. This happens because energy must be supplied first, against the cohesive forces of the solute in solid state to separate them, and second, against the cohesive forces of the solvent to create the respective cavity (for solute accommodation).…”

The solubility of liquid and solid compounds in dry octan-1-ol

“…The very useful statistic, PSD, the predicted standard deviation is obtained from the leave-one-out Finally, we combine the two data sets, together with some additional compounds taken from the literature (Alexander et al, 1977;Gharavi et al, 1983;Martin, Wu and Beerbower, 1984;Niimi, 1991;Pinsuwan, Li and Yalkowsky, 1995;Bernazzani et al, 1995;Kristl and Vesnaver, 1995;Bustamante, Pena and Barra, 1998;Martinez and Gomez, 2001;Avila and Martínez, 2002;Perlovich et al, 2003Perlovich et al, , 2010Perlovich et al, , 2011Ran et al, 2002;Sepassi and Yalkowsky, 2006;Quingzhu et al, 2007Quingzhu et al, , 2008Thimmasetty et al, 2008) or from our own previous work (Fletcher et al, 1998;Hoover et al, 2004Hoover et al, , 2005aHoover et al, , 2005bHoover et al, , 2006Charlton et al, 2005;Stovall et al, 2005aStovall et al, , 2005bFlanagan et al, 2006aFlanagan et al, , 2006bHolley et al, 2011;Ye et al, 2011;Stephens et al, 2012;Wilson et al, 2012;Bowen et al, 2013). For most of the common compounds in the Admire and Raevsky data sets, the listed log Soct(mol/L) values were the same.…”

“…Not surprisingly, there have been a number of methods put forward for the correlation and prediction of octanol solubility of liquids and solids (Li, Pinsuwan and Yalkowsky, 1995;Sepassi and Yalkowsky, 2006;Admire and Yalkowsky, 2013;Raevsky and Schaper, 2008;Raevsky, Perlovich and Schaper, 2007). It is important to note that all this work refers to dry octanol; it is well-known that solubilities in wet (water-saturated) octanol and dry octanol are not the same (Bernazzani, Cabani, Conti and Mollica, 1995;Kristl and Vesnaver, 1995;Martínez and Gómez, 2001), possibly because the microscopic structure of wet and dry octanol are not the same (Chen and Siepmann, 2006).…”

Thermodynamic study of the solubility of some sulfonamides in cyclohexane

“…The term (V 2 φ 1 2 / RT) may be considered constant at the same temperature, then γ 2 depends almost exclusively on w 11, w 22 and w 12 . 23 It can be seen in equation 10 that the contribution of w 22 is constant for each sulfonamide, since it represents the work necessary to take a molecule to the vapor state. The greater γ 2 values in cyclohexane (close to 10 6 ) compared with those obtained in octanol, water or mutually saturated solvents, 5 which are hydrogen bonding solvents (close to 10 3 ), indicate that the contribution of w 11 in cyclohexane (aprotic solvent) is lower, hence the w 12 values (relative to solute-solvent interactions) are also very small.…”