Quality by Design Approach to Develop Stability Indicating Method to Quantify Related Substances and Degradation Products of Sacubitril by High Performance Liquid Chromatography.

Sacubitril (SBT) is a neprilysin inhibitor, approved by food and drug administration (FDA) in 2015, under the FDA's priority review process. In this work, we report the validated stability indicating method of SBT by employing quality by design (QbD) principles related to analytical method development, capable in separation of 11 impurities. Chromatographic separation was performed on an ascentis phenyl hexyl column using 10 mM KH2PO4 as a mobile phase-A and the pH adjusted to 2.1. Methanol: acetonitrile (70:30 v/v) solvent mixture was employed as the mobile phase-B in a gradient mode of elution at a flow rate 0.8 mL/min at 30°C. The column effluents were monitored by a photo diode array detector set at a wavelength of maximum absorption 254 nm noted for all the impurities and furthermore for SBT. This method was remarked to be accurate in the range from 92 to 116%, precise with relative standard deviation 0.9% for SBT (0.8 mg/mL) and 1.0 to 2.1% for its related impurities (0.0005 mg/mL) also linear with correlation coefficient r ≥ 0.9989. The limits of quantification for all impurities were 0.05% with respect to sample concentration 0.8 mg/mL. The developed method revealed a good method operable design range for the experimental chromatographic conditions. Forced degradation of SBT carried under acidic, basic and oxidative stressed conditions manifested that the method is stability indicating.