Stability indicating assay method for simultaneous estimation of nebivolol and valsartan in pharmaceutical dosage form by RP-HPLC

A simple, rapid, precise, and accurate isocratic reversed-phase stability indicating HPLC method was developed and validated for simultaneous determination of the nebivolol and valsartan in the tablet dosage form. The effective chromatographic separation was achieved by a YMC pack pro octadecyl silane (150×4.6 mm, 3 μm) column using a mobile phase composed of methanol: acetonitrile: 0.05 M potassium dihydrogen phosphate buffer (pH=3.0 with 10% ortho phosphoric acid after addition of 0.2% triethylamine) (30:30:40, v/v/v) at a flow rate of 1 mL/min and UV detection at 282 nm. Drugs were subjected to the acid, base, oxidation, heat, and photolysis to apply the stress. Linearity ranges were 5–30 μg/mL (r2= 0.9989) for nebivolol and 80-480 μg/mL (r2=0.9991) for valsartan. Limit of detection was 0.38 μg/mL and 1.08 μg/mL for nebivolol and valsartan, respectively. The limit of quantification for the nebivolol and valsartan was 1.15 μg/mL and 3.27 μg/mL, respectively.