Interactions of Aluminum, Magnesium, and Calcium Ions with Nalidixic Acid

Interaction of nalidixic acid with aluminum ion was revealed by spectrophotometric study. Stoichiometry of the nalidixic acid-aluminum ion complex was estimated to be 3 to 1 by the method of continuous variations. The interaction was further supported by an increase in solubility of the drug with increasing concentration of aluminum ion, by a decrease in (carbon tetrachloride/acetate buffer, pH3.3) partition coefficient with increasing concentration of aluminum ion in the aqueous layer, and by a decrease in the permeation rate of the drug through a cellulose membrane in the presence of aluminum ion in the donor compartment. Interaction of nalidixate anion with magnesium and calcium ions was also shown spectrophotometrically.