A simple, rapid and sensitive liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) assay method is proposed for the determination of tolvaptan in human plasma samples using tolvaptan d7 as internal standard (IS). Analyte and the IS were extracted from 100 μL of human plasma via simple liquid-liquid extraction. The chromatographic separation was achieved on a C18 column using a mixture of methanol and 0.1% formic acid buffer (80:20, v/v) as the mobile phase at a flow rate of 1.0 mL/min. The calibration curve obtained was linear (r(2) ≥ 0.99) over the concentration range of 0.05-501 ng/mL. Method validation was performed as per US Food and Drug Administration guidelines and the results met the acceptance criteria. The intra-day and inter-day precision (coefficient of variation) and accuracy results in three validation batches across five concentration levels were well within the acceptance limits. A run time of 2.0 min for each sample made it possible to analyze more samples in a short time, thus increasing the productivity. The proposed method was successfully applied to a pharmacokinetic study of 15 mg and 60 mg tolvaptan tablet formulation in healthy South Indian male subjects under fasting condition.
A series of novel 3-(substituted)-2-(substituted quinazolinylamino)quinazolin-4(3H)-ones were synthesized by the reaction of 3-(substituted)-2-hydrazino-quinazoline-4(3H)-ones with 2-phenyl-3,1-benzoxazin-4-one. The starting materials 3-(substituted)-2-hydrazino-quinazolin-4(3H)-ones were synthesized from various primary amines by a multistep synthesis. All the title compounds were tested for their antibacterial activity using ciprofloxacin as reference standard. Compounds 3-(4-fluorophenyl)-2-(4-oxo-2-phenylquinazolin-3(4H)-ylamino)quinazolin-4(3H)-one (9a) and 3-(4-chlorophenyl)-2-(4-oxo-2-phenylquinazolin-3(4H)-ylamino)quinazolin-4(3H)-one (9h) emerged as the most active compounds of the series. These compounds have shown most potent antibacterial activity against the tested organisms of Proteus vulgaris and Bacillus subtilis having zone of inhibition values of 1.1 cm and 1.4 cm for compound 9a 1.2 cm and 1.0 cm for compound 9h, respectively.
The whole plant of the methanolic extract from Leucas cephalotes was screened for in vitro antioxidant (using the DPPH method), in vivo analgesic (using hot plate test in mice) and anti-inflammatory (using rat paw edema test) activities. The methanolic extract of Leucas cephalotes (MELC) scavenged the DPPH radicals in a dose-dependent manner. The IC 50 value to scavenge DPPH radicals was found to be 421.3µg/ml. A significant (p<0.0005) analgesic activity was observed at 60 min with 200 mg/kg, and 400 mg/kg exhibited maximum activity. The maximum anti-inflammatory response was produced at 3 hr and 2 hr with doses of 200 and 400 mg/kg, respectively. These results suggest that the methanolic extract from Leucas cephalotes exerts significant analgesic and anti-inflammatory effects, which were comparable with standard drugs. O extrato metanólico total de Leucas cephalotes foi submetido à triagem para as atividades antioxidante in vitro (utilizando o método DPPH), analgésica (utilizando teste da placa quente, em camundongos) e antiinflamatória (utilizando teste de edema da pata de rato), nas doses de 200 e 400 mg/kg. O extrato metanólico de Leucas cephalotes (MELC) inativou radicais difenil picril hidrazila (DPPH) de forma dose-dependente. O IC 50 para essa atividade foi de 421,3 µg/mL. Observou-se atividade analgésica significativa (p<0,0005) a 60 minutos, com 200 mg/kg, e, com 400 mg/kg, observou-se atividade máxima. A resposta antiinflamatória máxima foi produzida, respectivamente, em 3 h e 2 h, com doses de 200 e 400 mg/kg. Estes resultados sugerem que o extrato metanólico de Leucas cephalotes apresenta efeitos analgésico e antiinflamatório significativos, comparáveis aos fármacos padrão.
Unitermos
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