Desviaciones al modelo logarítmico-lineal en la solubilidad de ibuprofén y naproxén en mezclas cosolventes propilenoglicol-agua

The deviations observed in the solubility of ibuprofen (IBP) and naproxen (NAP) in propylene glycol (PG) + water (W) cosolvent mixtures with respect to the logarithmic-linear model proposed by Yalkowsky have been analyzed at 25.00 ± 0.05 ºC. Negative deviations were obtained in all cosolvent compositions for both drugs; they were greater for IBP. Another treatment, based on Gibbs free energy relationships, was also employed showing an apparent hydrophobicity chameleonic effect, because at low PG proportions NAP is more hydrophobic, whereas at high PG proportions IBP is more hydrophobic. The results are discussed in terms of solute-solvent and solvent-solvent interactions.

Epinikia

Digitoitu 14. 8. 2008.

Epiphrase

Digitoitu 14. 8. 2008.

Jousikvartetto 4, G-duuri

Soitinnus: viulut (2), alttoviulu, sello.

Juhlakantaatti "Erektheion"

Digitoitu 14. 8. 2008.

86 T

Soitinnus: oktetti.

Sellokonsertto

Digitoitu 11. 8. 2008.

4 kuolemankuvaa [op. 8]

Loppuu kesken.

Elegia I

Digitoitu 11. 8. 2008.

Exercitium academicum

Invocatio: Deo duce.

Entalpía de disolución de sulfacetamida sódica en agua: comparación entre la calorimetría isoperibólica de solución y el método de van't Hoff

The dissolution enthalpy (ΔH0soln) of sodium sulfacetamide in water was determined by means of isoperibolic solution calorimetry. It was found that ΔH0soln diminishes as the drug concentration increases. Otherwise, the calorimetric values obtained as a function of the drug concentration were significantly different than those predicted by the van't Hoff method. It was demonstrated that the later is not a fully reliable method for the determination of ΔH0soln values in the specific case of highly soluble sodium salts. The observed phenomenon could be explained by the presence of strong solute-solute interactions at high salt concentrations, in addition to solute-solvent and solvent-solvent interactions.

[hepreaa] sive eversio Sodomae & Gomorrhae

Invocatio: [hepreaa].

De methodo soliditates corporum duplici integratione eruendi

Dedicatio: Hans Henrik Gripenberg.

Revelationi quid debeat philosophia nostra

Invocatio: D.A.G.

Quod liber vitae naturalis Exod. XXXII. 32

Invocatio: [hepreaa].