A new RP-HPLC approach for estimation of potential impurities of Fosamprenavir - method development and validation

The current work aims to develop a reliable and robust RP-HPLC method for analyzing Fosamprenavir and its potential impurities, including isomer, amino, propyl, nitro, and Amprenavir. The method used a Zobrax C18 column with a mobile phase of 0.1% V/V orthophosphoric acid in water and acetonitrile in gradient elution at a flow rate of 1 mL/min to accomplish efficient separation with detection at 264 nm and column temperature of 30 ± 2⁰C. A diluent with a 1:1 water-to-acetonitrile ratio was used to prepare standard and sample solutions. The developed approach was validated as per ICH Q2(R1) guidelines. Fosamprenavir, Amino, Propyl, Isomer, Nitro impurities, and Amprenavir impurities were eluted at retention time (RT) of 5.3 min, 2.3 min, 4.3 min, 4.7 min, 8.1 min and 8.6 min correspondingly with good resolution within a 10-minute run time. Method validation confirmed system suitability, linearity (R² = 0.999), good sensitivity (LOD/LOQ), specificity, precision (% RSD: 0.5-1.7), accuracy (% recovery: 90.9-104.3%), and robustness. The optimized approach excelled existing methods in lower retention time, run time, sensitivity, and linearity for all potential impurities, making it a novel and trustworthy method for monitoring Fosamprenavir drug quality and assessing stated impurities. The established method allows precise measurement of Fosamprenavir and related substances, supporting drug safety and regulatory compliance.