ABSTRACT
The present study describes the isolation, characterization and in vitro cytotoxic effect of all forced degradation products of niclosamide (NCM) an anthelmintic class of drug used specifically to treat tapeworms. NCM was subjected to forced degradation involving hydrolysis (acidic, alkaline and neutral), oxidative, photolysis and thermal stress, as per ICH (Q1A (R2)) suggested conditions. The drug under hydrolytic (acidic and basic) conditions showed extensive degradation, while it was stable under neutral hydrolytic, oxidative, photolytic and thermal stress conditions. A total of four degradation products (DPs) were observed and chromatographic separation of drug and its degradation products were achieved on a reverse phase Fortis diphenyl column (150×4.6mm, 5µm) using 0.1% formic acid and acetonitrile as mobile phase in gradient mode. All the four degradation products were isolated by semi preparative LC and its structures were characterized and confirmed by high resolution MS and 1H NMR spectroscopic techniques. In view of safety aspects, cytotoxicity assay were carried out for NCM and its four degradation products on human mononuclear cells and cell lines depicting the major organelle: neuronal (Neuro 2a), hepatic (HepG 2) and alveolar (A549). NCM was found to be non toxic on human mononuclear cells and cell lines at tested concentrations. However DP-1, DP-2, DP-3 and DP-4 showed significant increase in LDH release as compared to control at a concentration of 100µM. DP-1 and DP-3 exhibited toxicity on A549 cells with an IC50 of 92.18±4.93µM and 65.42±6.29µM respectively. DP-2, DP-3 and DP-4 were cytotoxic to Neuro 2a cells with an IC50 of 63.62±3.85µM, 86.09±6.19µM and 42.81±8.10µM respectively. The degradation products were found to be nontoxic on HepG 2 cells.
Subject(s)
Anthelmintics/isolation & purification , Chromatography, Liquid/methods , Magnetic Resonance Spectroscopy/methods , Niclosamide/isolation & purification , Spectrometry, Mass, Electrospray Ionization/methods , A549 Cells , Anthelmintics/chemistry , Anthelmintics/toxicity , Cell Survival/drug effects , Drug Stability , Hep G2 Cells , Humans , Hydrolysis , Leukocytes, Mononuclear/drug effects , Molecular Structure , Niclosamide/chemistry , Niclosamide/toxicity , PhotolysisABSTRACT
Racecadotril, an enkephalinase inhibitor, was subjected to hydrolysis (acidic and alkaline), oxidation, photolysis and thermal stress, as per ICH specified conditions. The drug showed extensive degradation under acidic, basic hydrolysis and oxidative stress conditions whereas, it was stable under other stress conditions. A total of seven degradation products (DPs) were observed. The chromatographic separation was optimized on Acquity HSS Cyano (100×2.1mm, 1.8µ) column using 0.1% formic acid and acetonitrile as mobile phase in gradient mode. Six DPs were characterised by LC-MS/MS and DP1 by GC-MS. The major DPs (DP 2 and DP 5) were isolated and characterised by NMR. This is a typical case of degradation where co solvent methanol reacts with racecadotril leading to the formation of pseudo DPs, DP 6 and DP 5. Interestingly the MS/MS spectra of protonated drug, DP 4 and DP 7 showed product ions which were formed due to intramolecular benzyl migrations. In vitro cytotoxic activity studies on isolated DP 2 and DP 5 revealed that the former has no cytotoxic nature, whereas the latter has potential pulmonary and hepatic toxicity.
Subject(s)
Solvents/chemistry , Thiorphan/analogs & derivatives , Acetonitriles/chemistry , Chromatography, High Pressure Liquid/methods , Drug Stability , Formates/chemistry , Hydrolysis , Magnetic Resonance Spectroscopy/methods , Oxidation-Reduction , Photolysis , Tandem Mass Spectrometry/methods , Thiorphan/chemistryABSTRACT
Pioglitazone is an oral anti-hyperglycemic agent. It is used for the treatment of diabetes mellitus type 2. It selectively stimulates nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-gamma). It was the tenth-best-selling drug in the U.S. in 2008. This article examines published analytical methods reported so far in the literature for the determination of pioglitazone in biological samples and pharmaceutical formulations. They include various techniques like electrochemical methods, spectrophotometry, capillary electrophoresis, high-performance liquid chromatography, liquid chromatography-electrospray ionization-tandem mass spectrometry and high-performance thin layer chromatography.
