Correlated quantification using microbiological and electrochemical assays for roxithromycin determination in biological and pharmaceutical samples

• Published in: Talanta (Oxford) 2020-05, Vol.211, p.120703-120703, Article 120703
• Main Authors: Mahmoudi, Abdelghani, Tertiş, Mihaela, Simon, Laura-Mihaela, Van Schepdael, Ann, De Francia, Silvia, Junie, Lia-Monica, Săndulescu, Robert
• Format: Article
• Language: English
• Subjects: Cyclic voltammetry; Differential pulse voltammetry; Human serum; Microbiological assay; Pharmaceutical dosage form; Roxithromycin
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2019.120703

Microbiological and electrochemical assays, applying the cylinder-plate and differential pulse voltammetry as techniques, are reported for the quantitative determination of roxithromycin in serum and solid pharmaceutical form. The microbiological assay is based upon the inhibitory effect of this drug on the strain Bacillus subtilis ATCC 9372 used as the test microorganism. Linearity of the calibration curve was observed over the concentration range of 8.37–83.70 μg mL−1, with relative standard deviation values less than 5.0%. The electrochemical behavior of roxithromycin was studied at a graphite screen-printed electrode modified with graphene by using cyclic voltammetry and differential pulse voltammetry. The current value of the oxidative peak obtained for roxithromycin at 0.65 V vs. Ag/AgCl in 0.03 mol L−1 phosphate buffer solution (pH 7.0) with a scan rate of 0.1 V-1 is a linear function of the concentration in a range of 4.19–83.70 μg mL−1 (5–100 μmol L−1). A comparative study was carried out and both methods were applied for the determination of roxithromycin in solid dosage forms and spiked serum. The bioassay results of human serum samples were in accordance with the electrochemical ones (R2 = 0.988, P