Separation and Characterization of the Related Substances of Bedaquiline Fumarate Using HPLC and Spectral Methods.

The study focuses on isolating and characterizing the potential degradation products (DPs) and impurities of Bedaquiline fumarate in bulk drug form. A stability-indicating related substance method was developed and validated using high-performance liquid chromatography. Agilent Poroshell 120EC- C18 (150 mm × 4.6 mm, 2.7 µm) column showed an optimum separation of 10 analytes. The mobile phase contained 0.05% trifluoroacetic acid, acetonitrile and methanol in a time gradient mode. Bedaquiline fumarate was susceptible to acid hydrolysis, oxidation, base hydrolysis and showed three potential DPs, including DP-1, DP-2 and Impurity-8. Degradation products, DP-1 and DP-2, were isolated and characterized by ESI-MS, 1H, NMR and 13C NMR spectroscopy. The developed method was validated according to ICH tripartite guidelines and showed adequate specificity, accuracy and linearity. The limit of detection and limit of quantitation were 0.05 and 0.15 µg/mL, respectively.

Identification and characterization of Prothionamide degradation impurities by mass spectrometry, NMR spectroscopy, and ultra high performance liquid chromatography method development.

Stability-indicating and liquid chromatography-mass spectrometry compatible ultra high performance liquid chromatography method was developed for the degradation and drug substances related impurities of Prothionamide. Forced degradation of Prothionamide was carried out under acidic, basic, thermal, oxidative, and photolytic stress conditions. The impurities separation was achieved on Acquity UPLC BEH-C18 (50 mm × 2.1 mm, 1.7 µm) with the mobile phase of 10 mm ammonium acetate pH 6.0 and Acetonitrile in a time gradient mode. Related substances by ultra-performance liquid chromatography method was validated according to ICH tripartite guidelines. Degradation products were isolated by Column chromatography and characterized by liquid chromatography-mass spectrometry, 1 H, and 13 C nuclear magnetic resonance spectroscopy. The developed related substances method showed adequate specificity, sensitivity, accuracy, linearity (0.4-1.5 µg/mL), precision, and robustness in line with ICH tripartite guidelines for validation of analytical procedures. Limits of detection and quantitation were 0.1 and 0.4 µg/mL, respectively, for Prothionamide and all the impurities. The method was found to be linear with a correlation coefficient > 0.99, precise (%RSD < 5.0), robust and accurate (%recovery 85-115%).