Study of Stability Constant of Some Transition Metal Complexes Formed With 4-[(1R)-2-amino-1-hydroxyethyl] benzene-1, 2-diol.

Abstract

The Simple, selective, and expeditious spectrophotometric methods have been developed for the determination of complexation of 4-[(1R)-2-amino-1-hydroxyethyl] benzene-1,2-diol with metal ions in pharmaceutical field. The method was based on complex formation between the antihypotensive drug and transition metal ions in a basic medium (pH 9.2). The colored complexes were measured at 280 nm wavelength for 4-[(1R)-2-amino-1-hydroxyethyl] benzene-1, 2-diol. The different experimental parameters affecting the development and stability of the colour were carefully studied and optimized. The stability constant of complex were calculated to be Ag(Ι)-4-[(1R)-2-amino-1-hydroxyethyl] benzene-1,2-diol is 4.34, Pd (ΙΙ)-4-[(1R)-2-amino-1-hydroxyethyl] benzene-1,2-diol is 5.75 & Cd (ΙΙ) - 4-[(1R)-2-amino-1-hydroxyethyl] benzene-1,2-diol is 3.82 by job’s continuous variation method. The stoichiometry of the complexes formed between the antihypotensive drugs and the metal ions was 1:1 M/L ratio. The proposed method was further applied to the determination of drug in pure and dosage forms. The results obtained were in good agreement with those obtained by a reference to UV–Visible Spectrophotometric method.