Stability Constant of Ce(III), Pr(III) and Tb(III) Chelates with Some Substituted Drugs

Abstract

The interaction of Ce(III), Pr(III) and Tb(III) metal ions with cefadroxyl or 8-[2-amino-2-(4-hydroxylphenyl)acetyl]- amino-4-methyl-7-oxo-2-thia-6-azobicyclo[4,2,0]oct-4-ene 5-carboxylic acid (ligand-1), deoxycycline or 4-(dimethylamino)- 1,4,4a,5,5a,6,11,12a-octahydro-3,6,10,12,12a-pentahydroxy- 1,11-dioxonaphthene-2-carboxamide (ligand-2) and dexamethasone or 9-fluro-11β, 17,21-trihydroxy-16a-methylpregna- 14-diene-3,20-dione (ligand-3) have been investigated by pH-metric technique at 0.1 M ionic strength and at 27 ± 0.1 ºC in 70 % DMF-water mixture. The data obtained were used to estimate the values of proton-ligand stability constant (pK) and metal ligand stability constants (log K). It is 1:1 and 1:2 complexes with all the three ligands.