Zeitschrift für Bioanalyse und Biomedizin

LC-MS multiple reaction monitoring (MRM) method had been evaluated for the determination of the very low level of 4-Oxiranylmethoxy-9H-Carbazole in drug substances such as Carvedilol (U.S. Pharmacopoeia (USP), 32NF-27,British pharmacopoeia (BP), 2009, Martindale 35 th edition) This 4-Oxiranylmethoxy-9H-Carbazole have been identi fi ed as potential genotoxic impurity. LC-MS was found to be more promising and the limit of quanti fi cation was 15 μ g/gm.

The present article reports the synthesis of a series of some new 1-acyl/ benzoyl -1-anilido-4-methyl /aryl-1, 3-butadiene derivatives (II - IV) by warming primary heteroamines and/ or sulfa drugs with pre heated ethyl acetoacetate and / or ethyl benzoylacetate in dry conditions followed by condensation with unsaturated aromatic aldehydes in boiling ethanol-piperidine. The chemical structures of the compounds were characterized via their elemental analysis and spectroscopic measurements (UV Vis., IR, 1 HNMR). Some of the compounds (IIId, e, f, IV d, e,f) were tested as antimicrobial and photochemical probe agents. Compound IVa was physically loaded onto polyurethane solid sorbent and successfully used for the removal and / or pre concentration of bismuth (III) from industrial wastewater. The voltammetric behavior of the two compounds IIa and IVa in N, N-dimethylformamide was investigated.

A simple, speci fi c and rapid LC–MS/MS method has been developed and validated for the estimation of curcumin in rat plasma, using biochanin as internal standard (IS). The assay procedure involved liquid–liquid extraction of curcumin and IS from rat plasma. The recovery of curcumin and IS in rat plasma were 87.62 and 88.25%, respectively. The resolution of peaks was achieved with 0.01 M ammonium acetate (pH 5.5):acetonitrile (10:90, v/v) on a Supelco Discovery C18 column. The total chromatographic run time was 4 min. Speci fi city and matrix effect on ionization was determined and found that method was speci fi c and there was no signi fi cant matrix effect. The method was proved to be accurate and precise at linearity range of 10–2000 ng/mL with a correlation coef fi cient (r) of ≥ 0.995. The MS/MS ion transitions monitored were 367 → 217 for curcumin and 283 → 268 for IS. The intra- and inter-day assay precision ranged from 2.79 to 8.20% and 4.15 to 7.76%, respectively; and intra- and inter-day assay accuracy was between 92.83–107.83% and 93.92–104.26%, respectively. Practical utility of this LC–MS/MS method was demonstrated in a pilot pharmacokinetic study in male Sprague–Dawley rats following intravenous administration of curcumin.

Bioequivalence studies are generally performed as crossover studies and, therefore, information in the Intrasubject Coef fi cient of Variation (CV) is needed for sample size planning. Recently, a confusing point was noticed in calculating the Intrasubject Coef fi cient of Variation (CV) in crossover studies under the additive model (i.e. under normality assumption and the multiplicative mode (i.e under logarithmic distribution). The aim of this paper is to clarify this confusion. Methods used in calculating the Intrasubject Coef fi cient of Variation (CV) are reviewed in this paper from a statistical point of view.