Eco-friendly RP-HPLC determination of bambuterol hydrochloride and montelukast sodium in tablet dosage with dissolution analysis

A simple, eco-friendly, and precise isocratic RP-HPLC method was developed and validated for the simultaneous determination of bambuterol hydrochloride (BBL) and montelukast sodium (MTK). Separation was performed on an Inertsil C18 column (250 × 4.6 mm, 5 μm) using ethanol/0.025 M phosphate buffer (pH 3.0) at 70:30 (v/v) on an Agilent 1200 Infinity II system. The method complied with ICH criteria and showed linearity over 1.20–100.00 µg mL⁻¹ (BBL) and 5.00–100.00 µg mL⁻¹ (MTK). Application to a combined tablet dosage form yielded mean recoveries of 100.92 ± 1.08% (BBL) and 99.39 ± 1.41% (MTK). Dissolution profiling was performed in 900 mL of 0.5% sodium lauryl sulfate medium. Method greenness and sustainability were benchmarked against a reported procedure using multiple tools, Analytical Eco-Scale, MoGAPI, AGREE, RGB-12, D-CHEMS-1, GEAR, CaFRI, CACI, and BAGI demonstrating a safer solvent profile via ethanol/buffer. Notably, the separation time is longer (≈ 16 min), indicating a deliberate trade-off between reduced solvent hazard and throughput; analytical performance was maintained. Overall, the method offers a robust, greener alternative for routine assay and dissolution testing of BBL and MTK in pharmaceuticals.