Utilizing an air-assisted liquid-liquid microextraction based on a natural hydrophobic deep eutectic solvent for the efficient determination of the anti-conjunctivitis olopatadine

A simple, green, and efficient air-assisted hydrophobic natural deep eutectic solvent-based liquid-liquid microextraction (AA-NaDES-LLME) was developed for the determination of the new anti-conjunctivitis, olopatadine, in eye drops and aqueous humor prior to its spectrophotometric determination. The hydrophobic NaDES was prepared from menthol and n-octanol at a molar ratio of 1:1. The key parameters (NaDES volume, air cycles, pH, and ionic strength) affecting the AA-NaDES-LLME were optimized in detail using the One-Factor-At-a-Time (OFAT) approach. Under the optimized conditions, the method linearity (0.10-15.0 mu g/mL), limit of detection (0.046 mu g/mL), and limit of quantification (0.10 mu g/mL) were determined. The method was successfully applied to determine olopatadine in artificial aqueous humor and pharmaceutical eye drops in the ultra-trace range with the recovery values of 95.52-104.95%. The AA-NaDES-LLME method enables the selective extraction of olopatadine in a shorter time and uses less energy compared to similar studies. Lastly, a thorough assessment of the method's environmental impact was conducted using different tools, demonstrating its remarkable sustainability. The developed method exhibits substantial promise for implementation in quality control and drug biomonitoring.