Solubility and preferential solvation of meloxicam in ethyl acetate + ethanol mixtures at several temperatures.
- Resource Type
- Article
- Authors
- Cristancho, Diana M.; Martínez, Fleming
- Source
- Journal of Molecular Liquids. Dec2014 Part B, Vol. 200, p122-128. 7p.
- Subject
- *SOLUBILITY
*SOLVATION
*NONSTEROIDAL anti-inflammatory agents
*ETHYL acetate
*TEMPERATURE effect
*THERMODYNAMICS
*SOLUTION (Chemistry)
- Language
- ISSN
- 0167-7322
The equilibrium solubility of meloxicam (MEL) in ethyl acetate + ethanol mixtures at five temperatures from 293.15 K to 313.15 K was determined and the respective thermodynamic quantities of solution processes were calculated. Preferential solvation parameters of the drug were also derived by means of the inverse Kirkwood-Buff integrals method. The preferential solvation parameter by ethyl acetate δx 1,3 , is negative in ethanol-rich mixtures but positive in compositions from 0.38 to 0.80 in mole fraction of ethyl acetate. It is conjecturable that in ethanol-rich mixtures the interaction by acidic hydrogen-bonding by ethanol on the basic sites of MEL plays a relevant role in the drug solvation. The more solvation by ethyl acetate in mixtures of similar solvent compositions could be due mainly to polarity effects. Finally, the slight preference of this drug for ethanol in ethyl acetate-rich mixtures could be explained in terms of the common participation of basic sites in both solvents and/or the acidic site of ethanol with the respective counterparts of MEL. [ABSTRACT FROM AUTHOR]