White analytical insight for sensitive fluorescent determination of semaglutide and tirzepatide in pharmaceuticals and biological matrices

The present study is focused on the sensitive determination of newly FDA-approved glucagon-like-peptide agonists semaglutide (SEM) and tirzepatide (TIR). Direct, selective and label-free spectrofluorometric method was proposed and validated (according to ICH guidelines) for determination SEM and TIR in their pure form, newly approved pharmaceuticals and spiked human plasma. The developed method was based on measuring the native fluorescence of SEM and TIR in ethanol at 294.8 and 303 nm after being excited at 216 and 225 nm for SEM and TIR in order. The method sensibility allowed the quantification of both drugs in nano-scale up to 10 ng/mL. Several experimental variables including solvent type, surfactant, and pH were optimized after several attempts to get the best sensitivity for both drugs. The mean recovery percentage of SEM was compared and found in agreement with the reported method using student’s t-test and the variance ratio F-test. Additionally, the greenness and whiteness profiles for this approach were evaluated using the GAPI, AGREE, and RGB algorithm; the positive results supported its use as great candidates for successful implementation in quality control labs and the pharmaceutical analysis companies.