Stability Indicating 1st Derivative Synchronous Spectrofluorimetric Method for the Determination of the Newly Approved Antiviral Drug Daclatasvir in Presence of Its Oxidative and Photolytic Degradation Products: Application to Tablet Dosage Form

A highly sensitive, simple and rapid first derivative synchronous spectrofluorimetric method was utilized for the determination of daclatasvir dihydrochloride (DCV) in presence of its oxidative and photolytic degradation products. Where synchronous 1st derivative spectrofluorimetric approach was utilized to quantitatively determine DCV at 373 nm in presence of its oxidative degradation product and at 388 nm in presence of its photolytic degradation product that is obtained by exposing DCV to UV light at 312 nm, these were the zero-crossing wavelengths of degradation products without interference. The synchronous fluorescence was scanned at Δ λ of 80 nm. The method was found to be linear across the concentration range of 0.5-5.0 ng/mL with lower detection limit of 0.090 and lower quantification limit of 0.275 ng/mL (at 373 nm) and 0.268 ng/mL (at 388 nm). The adopted approach was successfully applied to commercial tablet and the results exhibited that the derivative synchronous fluorescence spectroscopy is a stabilityindicating method, suitable for routine use within a short analysis time. The proposed method was carefully validated for linearity, accuracy, precision, specificity and robustness.