Development and validation of a highly sensitive second derivative synchronous fluorescence spectroscopic method for the simultaneous determination of elbasvir and grazoprevir in pharmaceutical preparation and human plasma
Elbasvir and grazoprevir combination has been newly approved for the treatment of patients infected with hepatitis C virus. In the present work, a highly sensitive, selective and accurate second derivative synchronous fluorescence spectroscopic method was developed for the simultaneous determination of elbasvir and grazoprevir in their pharmaceutical dosage form without previous separation. The developed method based on the measurement of the synchronous fluorescence intensity of the studied drugs at constant wavelength difference (Δλ) = 50 nm and the peak amplitudes of the second derivative were measured at 308 and 389 nm for the quantitative analysis of elbasvir and grazoprevir, respectively. Different parameters that affect the synchronous fluorescence intensity of the cited drugs were carefully studied and optimized. Calibration graphs were found to be linear over the concentration range of 100–800 ng mL−1 for elbasvir and 150–900 ng mL−1 for grazoprevir. The developed method was successfully applied to the quantitative analysis of the two drugs in Zepatier® tablets and spiked human plasma. The results were statistically compared with another published analytical method with no significant difference by applying a Student t-test and variance ratio F-test.