Development of green micellar HPLC-DAD method for simultaneous determination of some sulbactam combinations used in COVID-19 regimen.

In a new attempt to separate some sulbactam combinations by green chemical method we came up with this research in which an ecofriendly, green, sustainable and selective method was established for separation of four antibiotics, namely, cefoperazone (CFP), cefixime (CFX), ampicillin (AMP) and sulbactam (SLB). No organic solvents were used in the composition of the mobile phase as it was replaced by mixing two surfactants together, sodium dodecyl sulfate (SDS) and polyoxyethylene-23-lauryl ether (Brij-35). Effect of varying the concentrations of the two surfactants on chromatographic separation was studied. Optimum separation was maintained using a mobile phase consisting of 0.01 mol/L SDS, 0.03 mol/L Brij-35, 0.4% Tri-ethylamine (TEA) and pH of 2.8 adjusted by using 1 M ortho-phosphoric acid on reversed phase Isère C18 BDS column with temperature of 40 °C at flow rate 1 mL/min, wavelength 215 nm, and the total run time was 6 min. Validation of the proposed method has been made according International Conference of Harmonization (ICH) guidelines at linearity range of 10-200 µg mL-1 for all drugs under study, high accuracy results (recovery range 98.39-100.35%). and the variation coefficient (RSD) of the points on the calibration curve was ranged from (0.1-1.7%) indicating precise method. The LOQ was (6.09 µg mL-1) for CFP, (6.07 µg mL-1) for CFX, (3.85 µg mL-1) for AMP and (7.20 µg mL-1) for SLB. Successful applications were made on marketed dosage forms with recovery range of (100.16-102.25%) and RSD of (0.03-1.88%). The method was verified on the Green Analytical Procedure Index (GAPI) and Analytical Greenness metric approach (AGREE) and it was found to be an excellent green alternative method.