The presence of impurities and degradation products will affect the pharmacokinetic, pharmacodynamic properties and alter the safety of the drug. Hence, development of stability indicating assay method is an integral part of quality product development and is crucial for the regulatory approval of drug products.
Acotiamide was subjected to stress degradation under hydrolytic, oxidative, photo and thermal stress conditions. The resulted degradation products (DPs), as well as process related impurity (IMP), were selectively separated from the drug on Waters Acquity HSS cyano column (100 × 2.1 mm, 1.8 μm) with mobile phase containing a gradient mixture of 0.1 % formic acid and acetonitrile (ACN) at flow rate of 0.25 mL min‐1.
The drug was found to degrade in hydrolytic (Acidic and basic), oxidative and photolytic stress while it remained stable in neutral hydrolytic and thermal stress conditions. The seven degradation products (DPs) and one process related impurity (IMP) were observed. All the DPs and process IMP were well separated by the developed UHPLC method and subsequently characterized by UHPLC‐ESI‐QTOF‐MS/MS. The proposed UHPLC method was validated with respect to specificity, linearity, accuracy, precision and robustness as per ICH guideline, Q2 (R1).
All the observed DPs were new and formed by hydrolysis of an amide bond, phenyl ring hydroxylation and hydrolysis of methoxy group the phenyl ring. The despropyl process impurity was observed and well separated from the drug. The proposed UHPLC mass spectrometric method has greater utility in the identification of degradation products in much less time with great selectivity.