“SIMULTANEOUS DETERMINATION OF CO-ADMINISTERED METFORMIN AND AMIODARONE IN PHARMACEUTICAL PREPARATIONS AND SPIKED HUMAN PLASMA USING RP-HPLC METHOD”

The goal of this work is to establish a sensitive, accurate, precise, and selective RP-HPLC method for the simultaneous determination of metformin and amiodarone in bulk powder, pharmaceutical preparations, and plasma. Chromatographic separation was performed using a Kinetex C18 column (100 × 4.6 mm, 5 µm), with a mobile phase of acetonitrile:0.1% ortho-phosphoric buffer (pH 5.0) (30:70, v/v), degassed prior to use, delivered at a flow rate of 1 mL/min in an isocratic mode at ambient temperature. The injection volume was 10 µL and UV detection was carried out at 230 nm. The retention times were 2.48 min for metformin and 4.36 min for amiodarone. Linearity was obtained over the range of 1–25 µg/mL for both drugs with correlation coefficients (r²) of 0.9999. The LOD and LOQ were 0.221 and 0.688 µg/mL for metformin, and 0.289 and 0.873 µg/mL for amiodarone, respectively. Mean recoveries were 99.32% and 99.46% for metformin and amiodarone, with %RSD values less than 2.0%, indicating high accuracy and precision. The method was successfully applied to pharmaceutical dosage forms and spiked human plasma with satisfactory recovery (98–99%). To the best of our knowledge, this is the first RP-HPLC method developed and validated for the simultaneous determination of metformin and amiodarone in pharmaceutical dosage forms and spiked human plasma, which highlights the novelty and significance of the study.