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%).

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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.

New mononuclear mixed ligand Cadmium(II) complexes of the type [Cd(L)(diimine)] (1,2) [where L = 2-(2-hydroxy-2-methyl-1-phenylpropylidene)hydrazinecarbothioamide; diimine = 2,2’-bipyridine (1), 1,10-phenanthroline (2)] have been synthesized and characterized by spectroscopic techniques such as FT-IR, UV-Visible, and1H and 13CNMR Spectroscopy. From the investigations of spectral data, it is evident that the heterocyclic bases (2,2’-bipyridine and 1,10-Phenanthroline) act as neutral bidentate ligand coordinating to the metal ion through two nitrogen donor atoms addition to azomethane nitrogen, thiolate Sulphur, and hydroxyl oxygen in the Schiff base ligand. The synthesized Schiff base metal chelates have been screened for their anti-microbial activities using the agar well diffusion method against different selected types of bacteria and fungi in addition to antioxidant activity. The prepared Schiff base ligand and its metal complexes exhibited good antimicrobial and antioxidant activities. The antibacterial and antifungal efficacy of Complex-1 was higher than that of all the prepared compounds. In the case of antioxidant activity, Complex-2 has stronger scavenging activity among them. Keywords: Cd (II) metal complexes, 2,2’-Bipyridine, 1,10-Phenanthroline, Antimicrobial activities.