A simple, accurate, precise and sensitive method has been developed for the determination of Vardenafil (Vd) using direct
coupled plasma atomic emission spectrometry. The ion associates formed as a result of the reaction of vardenafil with ammonium
reineckate, Mn(II) and Co(II) thiocyanates and sodium cobaltinitrite are precipitated. The solubility of the solid complexes
under the optimum conditions of pH and ionic strength was studied. Saturated solutions of each ion associate at different
temperatures under the optimum precipitation conditions were prepared, and the metal ion content in the supernatant was determined.
The solubility products were thus calculated at different temperatures, and the thermodynamic parameters ΔH, ΔG and ΔS were
calculated. The method has been used for the determination of vardenafil (1.36–68.32 µg·mL
−1) in pure solutions and in Levitra tablets.
Key words: Atomic emission spectrometry; vardenafil; ion associate complexes; pharmaceutical analysis.