An eco-friendly spectrophotometric analysis tool with whiteness assessment to assay erythromycin in pharmaceutical formulation through metal complexation with Ni2+: application to the microbiological activity using agar diffusion method

Abstract

A new, facile and eco-friendly spectrophotometric method for estimating erythromycin (ERY) in its dosage form has been proposed and validated. It depends on the formation of a complex between the drug and nickel at pH 7, using distilled water as a diluent, where the absorbance of the generated complex was measured at 228.5 nm. The formed complex followed a linear response over the concentration range of 80.0 to 300.0 µg/mL of ERY. The proposed method was fully validated according to international conference of harmonization (ICH) and was used to estimate the relevant concentration of the drug in its oral suspension formulation providing mean percentage recovery of 100.0±1.08 with a limit of detection and limit of quantification of 60 µg/mL and 80 µg/mL, respectively. the reaction stoichiometry was investigated and a reaction mechanism proposal was offered. Eventually, the antimicrobial effect of ERY and its metal complex with Ni2+ were compared using agar diffusion method, where no significant difference in their activities was observed.