Investigation of chromatographic conditions for developing a method to quantify losartan potassium in film-coated tablets using HPLC-PDA

To overcome the risk of salt precipitation associated with phosphate-buffered mobile phases specified in the Vietnamese Pharmacopoeia V, which may reduce the lifespan of chromatographic systems, a high-performance liquid chromatography (HPLC) method was developed and optimized without the use of a buffer system for quantifying losartan potassium in film-coated tablets. Key chromatographic conditions affecting the separation of the active ingredient and impurities were investigated using a Thermo 3000 system. The optimized conditions included a Phenomenex Kinetex C18 column (150 × 4.6 mm; 5 µm), a mobile phase of acetonitrile and 0.1% phosphoric acid solution (35:65, v/v), a flow rate of 1.0 mL/min, injection volume of 10 µL, column temperature of 25°C, and detection at 204 nm using a PDA detector. The method demonstrated excellent separation efficiency and fully satisfied analytical requirements, offering a safe and sustainable alternative for routine quality control.