Rapid ultraviolet spectrophotometric assay of benzoyl metronidazole in an oral suspension

Abstract

A procedure is described for the rapid determination of benzoyl metronidazole in an oral suspension which is based on measurement of the change in absorbance at 276 nm during alkaline hydrolysis of the compound in 2 mol dm^–3 NaOH. The change in absorbance follows a linear relationship with concentration in the range 3–18 µg ml^–1. Results of the determination of benzoyl metronidazole in an oral suspension and of the recovery experiments performed on this formulation, and also on various individual excipients and other additives, confirmed the applicability of the proposed method to complex formulations.