Development of hybrid spectrofluorimetric method for simultaneous determination of Valsartan and Sacubitril in LCZ696 tablets.

A hybrid Spectrofluorimetric method was developed for the simultaneous determination of binary mixtures, without prior separation steps. It coupled synchronous spectrofluorimetry with derivative ratio mathematical treatment. The method was applied successfully to quantify a new model binary mixture consisting of Valsartan (VAL) and Sacubitril (SAC). This mixture was recently approved by FDA as LCZ696. It added a great value in reducing morbidity and mortality in resistant heart failure (HF) patients. First derivative ratio synchronous fluorescence was measured at 258-295 (peak-to-peak) and 204 nm for VAL and SAC, respectively. ICH guidelines were fulfilled for the method validation. VAL and SAC showed linear responses in the range of 60-200 and 20-200 ng mL, respectively. The proposed method was compared, in details, with the reported ones. Its high accuracy, selectivity, simplicity and affordable cost recommend method application in large-scale routine analysis of LCZ696 tablets. Moreover, reliable application of this new integrated spectrofluorimetric method suggests expansion of its application for various therapeutic combinations and different matrices.