Simultaneous ecofriendly HPLC determination of clotrimazole, miconazole, metronidazole, and lidocaine in pharmaceutical dosage forms.

The analysis of multicomponent pharmaceutical formulations containing drugs with significant diverse physicochemical properties, like 6 orders of magnitude of pKa values, which permanently represents a significant challenge in modern pharmaceutical analysis. The simultaneous determination of multiple active agents offers substantial advantages by reducing analysis time and resource consumption. Furthermore, the increased analytical demand during health emergencies highlights the necessity for validated, rapid, and reliable methods capable of supporting both therapeutic assessment and regulatory decision-making. In the present study, a reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and optimized for the simultaneous determination of four analytes: clotrimazole, miconazole, metronidazole, and lidocaine. Various approaches were investigated for mobile phase composition and column selection to achieve optimal separation and accurate quantitative determination. Chromatographic separation was examined using several columns, including Waters Spherisorb CN (250 × 4.6 mm, 5 µm), LiChrospher 100 CN (125 × 4 mm, 5 µm), LiChrospher 100 CN (250 × 4 mm, 5 µm), Zorbax SB CN (150 × 4.6 mm, 3.5 µm and 250 × 4.6 mm, 5 µm), Zorbax Rx C8 (250 × 4.6 mm, 5 µm), and Zorbax SB Phenyl (150 × 4.6 mm, 3.5 µm). Isocratic elution was employed using mixtures of acetonitrile, methanol, and phosphoric acid or trifluoroacetic acid in different proportions at flow rates of 1.0 and 1.2 mL min