New ecological first derivative synchronous spectrofluorimetric method for simultaneous quantification of carvedilol and ivabradine in tablets

A new, rapid, selective, green, and highly sensitive method has been established to determine ivabradine and carvedilol simultaneously. The first derivative synchronous spectrofluorimetric approach was applied for the determination of the studied drugs. Assessment of the first derivative amplitude of carvedilol and ivabradine has been done at 339 nm and 298 nm respectively which are the zero crossing points of each other. The method validation is estimated and was found to be consistent with International Conference on Harmonization guidelines. Linearity was found to be in the range of 10.0 to 90.0 ng/mL for carvedilol and from 80.0 to140.0 ng/mL for ivabradine. The detection limits were found to be 1.2 ng/ mL and 3.3 ng/mL and the quantitation limits were 3.7 ng / mL and 10.0 ng /mL for carvedilol and ivabradine, respectively. The method was effectively applied for the determination of both drugs in their synthetic mixture in different ratios and in their prepared co-formulated tablets. The results were compared with those of comparison HPLC methods. Ethanol was used as a green solvent. The proposed method is suitable for the determination of ivabradine and carvedilol with satisfactory accuracy and precision. The greenness of the method was evaluated using four assessment tools, i.e. NEMI, GAPI, Eco-scale, and AGREE. The proposed method is simple with a low cost compared to HPLC methods.

Green fluorometric strategy for simultaneous determination of the antihypertensive drug telmisartan (A tentative therapeutic for COVID-19) with Nebivolol in human plasma

Telmisartan (TEL) and Nebivolol (NEB) are frequently co-formulated in a single dosage form that is frequently prescribed for the treatment of hypertension, moreover, telmisartan is currently proposed to be used to treat COVID19-induced lung inflammation. Green rapid, simple, and sensitive synchronous spectrofluorimetric techniques for simultaneous estimation of TEL and NEB in their co-formulated pharmaceutical preparations and human plasma were developed and validated. Synchronous fluorescence intensity at 335 nm was used for TEL determination (Method I). For the mixture, the first derivative synchronous peak amplitudes (D¹) at 296.3 and 320.5 nm were used for simultaneous estimation of NEB and TEL, respectively (Method II). The calibration plots were rectilinear over the concentration ranges of 30-550 ng/mL, and 50-800 ng/mL for NEB and TEL, respectively. The high sensitivity of the developed methods allowed for their analysis in human plasma samples. NEB`s Quantum yield was estimated by applying the single-point method. The greenness of the proposed approaches was evaluated using the Eco-scale, National Environmental Method Index (NEMI), and Green Analytical Procedure Index (GAPI) methods.