Eman S Elzanfaly, Ahmed S Saad and Abd-Elaziz B Abd-Elaleem
Smart simple spectrophotometric method was developed for simultaneous determination of compounds with interfering spectra in binary mixtures without previous separation. The proposed method showed significant advantages over the conventional methods regarding minimal data manipulation and applicability. The new method is based on a modification for the ratio subtraction and derivative ratio methods. This modification enabled wider range of application. The proposed method was applied for the determination of tazarotene and its alkaline degradation product in laboratory prepared mixtures with mean percentage recoveries 99.68 ± 1.36 and 100.86 ± 1.09 respectively. The suggested method was validated according to USP guidelines and can be applied for routine quality control testing.