Abstract (EN):
Particular interest in analytical applications of micellar systems derives from their important role in solubilization process as well as from their effects on overall reaction rates and equilibria. The tensioactive agents are one of the most important groups of adjuvants in pharmaceutical formulations and play an important role in the pharmacokinetic properties of the drugs. In this work we report the determination of the binding constants of substances with pharmacological interest, namely two ß-blockers (atenolol and nadolol) with SDS micelles. The binding constants were obtained by fluorimetric titration and by solubility studies. The effects of SDS micellar solutions on the solubility of these compounds in basic and acidic media were determined by UV/visible spectroscopy and fluorimetry. All the studies were performed with an ionic strength 0.1 M in Na Cl and at 25°C. The fluorimetric and solubility results shows that binding constants for neutral species are smaller than those of positively charged. The association constants determined by these methods are in good agreement with those previously obtained by the potentiometric and spectrophotometric determination of acidity constants in SDS solutions.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
1