Sustainable chromatographic assays of a novel antifungal combination for keratomycosis

Abstract Keratomycosis, a sight-threatening fungal infection of the cornea, can be more effectively treated with a novel combination of Natamycin (NAT, 5%) and Fluconazole (FLC, 0.2%) than with NAT alone. To support the development of this therapy, new sustainable, eco-friendly, and sensitive analytical methods were developed for the simultaneous quantification of both drugs in pharmaceutical formulations. Two techniques were successfully employed. The first was a Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) method using an isocratic mobile phase of methanol and water (70:30%v/v) at a 1 mL/min flow rate. Detection was accomplished with both diode array (DAD) and fluorescence (FLD) detectors. The second technique was a Capillary Zone Electrophoresis (CZE) method utilizing a capillary (56 cm effective length, 50 μm internal diameter) at ambient temperature. Samples were injected hydrodynamically at 50 mbar pressure. The environmental sustainability and practical applicability of these methods were rigorously evaluated using modern assessment tools: the Greenness, Whiteness, and Blueness approaches. Furthermore, their innovative character was formally quantified using a novel metric, the Violet Innovation Grade Index (VIGI).