Development and validation of a stability-indicating assay method for determination of metronidazole benzoate in bulk: Spectroscopic approach

A new, simple, rapid, accurate, sensitive and cost effective spectrophotometric stability indicating assay method was developed for the quantification of metronidazole benzoate in bulk and validated according to ICH guidelines using different parameters. In the present study an attempted has been made to develop an effective method which will surpass the disadvantages associate with other reported methods like tedious in use, less sensitive and costly etc. The assay method was based on the forced degradation study of metronidazole benzoate under different ICH recommended stress conditions like hydrolytic, oxidation, thermal, and photolysis. Drug shown maximum absorption at 322nm and a regression coefficient value (R2) of 0.999 indicates linearity followed within the concentration range of 5µg/ml to 50µg/ml. During forced degradation study, metronidazole was significantly degraded in alkaline conditions whereas mild degradation occurs in acidic, neutral and oxidative stress. The drug was stable to dry heat and photolytic degradation conditions. Statistical validation result of the developed method indicates that it was a simple, precise, reproducible, selective, specific and accurate method for analysis of Metronidazole and could be successfully adopted to estimate the drug in bulk and formulations.