Development and validation of a green DLLME -spectrophotometric method for simultaneous determination of loratadine and Desloratadine by the formation of an ion-pair complex with determination alizarin yellow

A novel, eco-friendly analytical method has been developed and validated for the simultaneous determination of loratadine (LOR) and its active metabolite desloratadine (DES) using dispersive liquid-liquid microextraction (DLLME) coupled with UV–Visible spectrophotometry. The method is based on the formation of yellow-colored ion-pair complexes between LOR/DES and alizarin yellow (ALZ) in acidic media, followed by extraction with chloroform and ethanol as green solvents. Optimal absorbance was observed at 350 nm for LOR and 280 nm for DES. The method demonstrated excellent linearity (R 2 > 0.999), low detection limits (0.35 mg/L for LOR and 2.7 mg/L for DES), and high recovery rates (99.99–102.06 %). Validation was performed according to ICH guidelines, and the procedure was successfully applied to commercial pharmaceutical formulations. The proposed method is cost-effective, environmentally friendly, and suitable for routine quality control of antihistamine drugs.