Development and validation of high performance liquid chromatography with a spectrophotometric detection method for the chemical purity and assay of nepafenac.

•New HPLC UV method was developed to analyze the chemical purity and to determine the assay of nepafenac.•8 impurities of nepafenac (degradation and post synthesis products) were separated within 29min.•The degradation studies were carried on to verify the separation efficiency of the method.•The developed method allows simultaneous determination of nepafenac amount.•3 nepafenac batches from manufacturing process were analyzed.