Thermodynamic study of complex formation of β-cyclodextrin with ibuprofen by conductometric method and determination of ibuprofen in pharmaceutical drugs

The equilibrium constants and the thermodynamic parameters for complex formation of beta-cyclodextrin (beta-CD) with ibuprofen have been determined by conductivity measurements in water. The inclusion complexation of ibuprofen in beta-cyclodextrin (beta-CD) has been examined by means of the conductometric method. The results suggest that stable1:1 complex is formed between ibuprofen and beta-cyclodextrin. The thermodynamic parameters (Delta H degrees(c); Delta S degrees(c)) for this complexation reaction have been determined from temperature dependence of the stability constant using the van't Hoff plots. Based on the obtained results, a conductometric method for the determination of ibuprofen in the presence of beta-CD at 25 degrees C was developed in the range of 10(-3) -10(-5) mol dm(-1). The method was satisfactorily applied to the quantification of ibuprofen in pharmaceutical preparations. (C) 2013 King Saud University. Production and hosting by Elsevier B.V.