Development and validation of UV spectroscopic method for estimation of sacubitril and valsartan combination (LCZ696) in bulk and pharmaceutical tablet dosage forms

Abstract

Sacubitril and valsartan combination is a member of a new class of agents called angiotensin receptor-neprilysin inhibitors (ARNI’s) which combine neprilysin inhibitor and angiotensin receptor blocker (ARB). It is currently indicated for treating patients with heart failure with reduced ejection fraction (HFrEF) in place of an angiotensin-converting enzyme (ACE) inhibitor or ARB alone. The aim of present investigation is to develop a simple UV spectrophotometric method for the determination of sacubitril and valsartan combination in its pure form and pharmaceutical tablet formulations in 0.1N HCl (pH 1.2) and pH 6.8 phosphate buffer, and further to validate the developed method. The combination in bulk was estimated at λmax of 253 nm in 0.1N HCl and pH 6.8 phosphate buffer. The observed λmax was close to the calculated λmax predicted using Woodward Fieser rules. The method was validated using analytical parameters like linearity, precision, and accuracy as per guidelines laid down by International Conference on Harmonization (ICH). Beer’s law was obeyed in the concentration range of 1–20 μg/mL in both media with correlation coefficient value of 0.999. The accuracy was found between 99-101% in both media. The method showed good reproducibility with % RSD values less than 2. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.5353 μg/mL, 1.6222 μg/mL in 0.1N HCl and 0.395 μg/mL, 1.198 μg/mL in pH 6.8 phosphate buffer respectively indicating its sensitivity. Molar absorptivity of the drug was found to be 3.84x104, 3.68x104 L mole-1 cm-1 and Sandell’s sensitivity values were found to be 0.0249 and 0.025 μg cm-1/0.001 absorbance unit in 0.1 N HCl and pH 6.8 phosphate buffer respectively. The assay values of the drugs in pharmaceutical dosage forms were also found close to the labelled claim. The results demonstrated that the procedure is accurate, precise, and reproducible besides being simple, economical, and less time consuming and hence, suitably applied for routine analysis of sacubitril and valsartan combination in bulk, marketed tablet dosage forms and in vitro dissolution samples.