Abstract
Stability constant (Ke) for 1 : 1 inclusion complexes of α-and β-cyclodextrins with barbiturates, phenothiazines, sulfonylamides, and sulfonylureas were determined by high performance liquid chromatography (HPLC). The retention times of the drugs following the binding to cyclodextrins in aqueous mobile phase on ion exchange support were quantitatively treated to obtain the Ke values. The Ke values obtained by HPLC method were in fair agreement with those obtained by other methods such as solubility and spectroscopic methods. The advantages of HPLC method developed here were that Ke values could be rapidly obtained by simple procedure with minimum quantity of the drugs and reproducibility and accuracy were not less than other methods. Furthermore, this method was proved to be particularly suitable for chemically unstable compounds such as phenothiazines.