Stability-indicating UPLC-PDA Method for Ambrisentan Tablets and Identification of a Main Degradation Product by UPLC-MS/MS

Abstract

Background: Ambrisentan is a drug used to treat the pulmonary arterial hypertension symptoms, commercialized as coated tablets. Drug quality control is an essential part for the development and release of drugs for consumption; however, there are few studies related to the proposition of analytical methods and stability study for ambrisentan. Objective: The development of an UPLC assay of ambrisentan in tablets with degradation product`s elucidation was proposed. Methods: Tests with different solvents and chromatographic columns were carried out, achieving an optimal condition using mobile phase in gradient mode, Waters® BEH C18 column and detection at 260 nm. Results: Satisfactory system suitability was obtained (theoretical plates, sensitivity and resolution among peaks), with a reduced analysis time (6 minutes). The method was validated in accordance with the international guidelines and it demonstrated adequate specificity, either for the drug assay as for the identification and quantification of degradation product. It showed linearity (r= 0.999), accuracy (degradation products recovery: 98.47 - 102.44; assay recovery: 99.98 - 104.32%) and precision (RSD: 0.69), with limits of quantification and detection in suitable magnitude in order to evaluate possible drug degradation. Conclusion: UPLC method demonstrated to be fast with satisfactory robustness. The main ambrisentan degradation product formed under thermal stress conditions was elucidated by UPLC-MS/MS and its structure was suggested.