Green analytical protocol for the liquid chromatographic determination of ketoprofen in human urine after microextraction using Carbowax 20 M – modified cellulose membrane

• A Carbowax 20 M – modified cellulose membrane was utilized for the extraction of ketoprofen. • The FPSE membrane was found to be reusable at least 30 times. • Determination of ketoprofen in urine after oral administration of its pharmaceutical formulation. • The green character of the developed method was assessed using various metric tools. A Carbowax 20 M – modified cellulose membrane was utilized for the fabric sorptive phase extraction of ketoprofen from human urine samples followed by liquid chromatographic analysis. Among the various sorbents examined, the sol-gel Carbowax 20M-modified fabric phase sorptive extraction membrane was found to be the most effective for the drug extraction. Due to their engineered affinity, these membranes exhibit high permeability, enabling the extraction of biological samples without prior pretreatment. Experimental parameters were systematically studied and optimized using a face-centered central composite design and one-factor-at-a-time approaches. The analytical method was validated for linearity (25 – 2000 ng/mL), selectivity, limit of detection (LOD) (8 ng/mL), limit of quantitation (25 ng/mL), precision (<10.2 % in all cases), and accuracy (relative recovery: 82.9–101.6 %). The membranes maintained their performance for at least 30 extractions, with a maximum allowable deviation of 10 % from the initial performance. The green character and the applicability of the method were evaluated through ComplexMoGAPI, BAGI, AGREE and AGREEprep tools. The final method was successfully applied to detect ketoprofen in authentic human urine samples after oral administration of a ketoprofen-containing tablet (25 mg/tab).