Abstract

Methods for spectrophotometric determination of cephalosporin antibiotics ceftazidime and ceftriaxone using azocoupling reactions with 8-hydroxyquinoline have been developed. Optimal conditions for the diazotization of antibiotics in hydrochloric acid (C_HCl = 12 M) and subsequent azocoupling with 8-hydroxyquinoline in alkaline medium (0.16 M NaOH in the final volume) were established. The of azocopling products of violet and light red colors are formed, which are characterized by absorption maxima at 553 nm (ε₅₅₃ = 6.31·10³ M^-1 cm^-1) and 550 nm (ε₅₅₀ = 1.45·10⁴ M^-1 cm^-1) for ceftazidime and ceftriaxone, respectively. Stoichiometric ratios of the azo compounds components were determined using continuous variations methods and in both cases are 1:1. Sensitive methods of spectrophotometric determination of ceftazidime (LOD = 1.81∙10^-6 M) and ceftriaxone (LOD = 5.92·10^-7 M) have been developed. The selectivity of cephalosporin antibiotics spectrophotometric determination in the presence of auxiliary substance (sodium carbonate) has been investigated. The elaborated methods has been approved during the analyses of model solutions and the single component drug. The recommended procedure is well suited for the ceftazidime and ceftriaxone assay in medicine to assure high standards of quality control.

Keywords: cephalosporin antibiotics, ceftazidime, ceftriaxone, 8-hydroxyquinoline, diazotization, azocopling, spectrophotometry, drugs

Article language: Ukr