Evaluation and Application of ZIC-HILIC Columns Selectivity for Four Angiotensin Ii Receptor Blockers in Pharmaceutical Formulations

The present article describes and validates sensitive hydrophilic interaction liquid chromatography methods to simultaneously analyse four angiotensin II receptor blockers: valsartan, telmisartan, losartan, and irbesartan. Numerous chromatographic parameters were studied and optimized in detail. The best separation was obtained on two handmade columns (ZIC-S1 and ZIC-S4) using acetonitrile/sodium acetate buffer (40 mM, pH 4.75) as a mobile phase. The detection of target pharmaceuticals was obtained at 220 nm. The linear ranges of target drugs (valsartan, telmisartan, losartan, and irbesartan) were 0.02-4, 0.06-7, 0.005-6 and 0.08-5 μg/mL on ZIC-S1 and ZIC-S4 columns, respectively. The suggested methods demonstrated high precision (RSD ≤ 1.15), linearity (r² ≥ 0.9964), and accuracy (between 98.88 and 101%) with detection and quantitation limits of (0.0021-0.0550 and 0.0063-0.1666 μg/mL, respectively) for all target pharmaceuticals. The suggested methods have been validated and applied to pharmaceutical formulations, indicating that it is suitable for therapeutic drug monitoring of these medications.