Stability‐Indicating Reversed‐Phase High‐Performance Liquid Chromatography Method With Photodiode Array Detection for Simultaneous Quantification of Futibatinib and Binimetinib in Dual‐Drug‐Loaded Nanobubbles for Lung Cancer Therapy

ABSTRACT A robust, stability‐indicating reversed‐phase high‐performance liquid chromatography (HPLC) with photodiode array (PDA) detection was developed and validated for the simultaneous quantification of futibatinib (FTB) and binimetinib (BTB) in a dual‐drug‐loaded poly(lactic‐ co ‐glycolic acid) nanobubble formulation intended for targeted lung cancer therapy. The method was systemically optimized using an analytical quality by design approach, incorporating the Box–Behnken design for multivariate analysis of three critical method parameters. Chromatographic separation was achieved on a Waters X‐Bridge RP‐C18 column (250 × 4.6 mm 2 , 5 µm) using a mobile phase composed of 0.01 N KH 2 PO 4 buffer (potential of hydrogen [pH] 3.5, adjusted with 0.1% orthophosphoric acid) and acetonitrile in a 55:45 (v/v) ratio at a flow rate of 1.0 mL/min. Detection was carried out at 270 nm, with sharp and symmetrical peaks for BTB and FTB eluting at 4.938 and 7.198 min, respectively. The method was validated by International Council for Harmonisation (ICH) Q2 (R1) guidelines, demonstrating excellent linearity, accuracy, precision, robustness, and specificity. Forced degradation studies under photolytic, thermal, neutral, acidic, alkaline, and oxidative conditions confirmed the method's stability‐indicating capability. The developed HPLC–PDA method is suitable for routine analysis and quality control of FTB and BTB in nanopharmaceutical formulations.