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EN
Purpose: Development and validation of a selective analytical method to accurately and precisely quantify nicotine and cotinine levels in rat's plasma after exposure to tobacco cigarettes and tobacco water-pipe. Methods: An easy HPLC-Photodiode-Array Detection (PDA) method was developed and validated for simultaneous determination of nicotine and cotinine levels in plasma of 15 rats (10 rats after tobacco products exposure and 5 control rats). Nicotine and cotinine were extracted in one step from plasma using acetonitrile and concentrated to lowest volume using nitrogen stream. Results: The developed method offered a rapid analysis time of 14 min with single step of analytes extraction from rat's plasma with recovery percentage range between 93 and 95% and excellent linearity with correlation factor more than 0.994 with analytical range between 50 and 1000 ng mL⁻¹ and LOD of 25 ng mL⁻¹ and 23 ng mL⁻¹ for nicotine and cotinine, respectively. The analysis of rat's plasma after 28 days of exposure to tobacco cigarettes and tobacco water-pipe revealed that the average concentrations of 376 ng mL⁻¹ for cotinine and 223 ng mL⁻¹ for nicotine were obtained after tobacco cigarettes exposure, and 220 ng mL⁻¹ for cotinine and 192 ng mL⁻¹ for nicotine after tobacco water-pipe exposure. Conclusion: Higher nicotine and cotinine levels were found in plasma after tobacco cigarettes exposure than water-pipe exposure which may have potential undesirable effects on passive smokers in both cases.
EN
A new High Performance Liquid Chromatography–Photodiode Array Detector (HPLC–PDA) method has been developed for the chromatographic separation and simultaneous quantitative determination of nine bioactive compounds, i.e. four phenolic (gallic acid, ellagic acid, chebulinic acid, and tannic acid), two flavanoids (rutin and quercetin), two anthraquinones (sennoside A and B) and one oxygenated hydrocarbon (vitamin C) in a well-known Unani polyherbal formulation namely Itrifal’s. Separation was accomplished on a C18 LiChrospher 100 column (5 mm, 250 3 4.6 mm) with a gradient elution and recorded at 254 nm. The results demonstrated that the proposed method is reproducible, accurate, economic, and suitable for the quality control of traditional polyherbal Unani formulations containing complex compounds with different structures such as Itrifals.
EN
The US Food and Drug Administration (FDA) has affirmed the use of letrozole (LTZ combined with palbociclib (PLB) to treat breast malignant tumor growth in postmenopausal women. A straightforward and extremely sensitive reversed-phase high-performance liquid chromatography method with photodiode array detection (RP-HPLC–PDA) was created and validated for the simultaneous determination of LTZ and PLB in rat plasma. The parameters used to give the best separation were a C18 column (150 mm × 4.6 mm, 3.5 μm) as the stationary phase with an isocratic mobile phase composed of methanol–30 mM ammonium acetate at a ratio of 60:40 (v/v), pH = 5.5, a flow rate of 0.8 mL/min, and detection wavelengths of 240 and 220 nm for LTZ and PLB, respectively. The developed method was assessed by the FDA rules over a range of 10–600 ng/mL for LTZ and PLB. The mean of %recovery of LTZ and PLB extracted from rat plasma by acetonitrile-based deproteinization was 91.06 ± 2.73 and 90.30 ± 1.95%, respectively, and the limits of detection were 5 ng/mL for LTZ and 7 ng/mL for PLB in rat plasma. The mean values of Tmax and Cmax were 6 ± 0.00 h and 266.96 ± 21.23 ng/mL for LTZ and 4 ± 0.00 h and 508.75 ± 61.56 ng/mL for PBL, respectively, after intraperitoneal administration of both drugs to rats. The developed HPLC–PDA method was demonstrated to be robust and was effectively applied to study the pharmacokinetics of LTZ and PLB in rat plasma.
EN
Alectinib is a central nervous system-active small molecule anaplastic lymphoma kinase (ALK) inhibitor that is effective in the treatment of patients with ALK positive tumors, including advanced non-small cell lung cancers and lymphomas. A simple, isocratic high-performance liquid chromatography–photo diode array detection (HPLC–PDA) assay for measurement of alectinib in human plasma is described. Alectinib is extracted from the plasma matrix by addition of methanol, followed by centrifugation and acidification with 0.1% formic acid. It elutes with a run time of 4.6 min using a 250 mm × 4.6 mm RP-C18 column with 0.1% aqueous formic acid and methanol (35:65, v/v) and a flow rate of 1 mL/min. Detection was at 339 nm. Linear calibration plots were achieved in the range of 0.1–20 μg/mL for alectinib (r2 = 0.9996). With limits of detection and quantification of 0.05 and 0.1 μg/mL, respectively, and excellent precision (%CV < 10%), accuracy (bias < ±12%), and recovery (>97%) within the 1–20 μg/mL concentration range, this assay was suitable for measuring pre-dose alectinib concentrations in an adolescent receiving 600-mg doses twice daily.
EN
Simple and rapid reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated using Phenomenex Gemini c18 (4.6 x 250 mm, 5 μ) reverse phase column for the determination of LAF in human plasma, Solid Phase Extraction (SPE) technique was used for the extraction of analyte, detection was carried out by Photo Diode Array detector at 216 nm. Chromatographic resolution of the LAF was achieved within 4.6 min by using mobile phase Methanol and 5 mM Di-Potassium Hydrogen Phosphate Buffer (pH 9.5) (80:20, v/v), flow rate was 1.0 mL/min. Calibration curve was linear with correlation coefficient of 0.9996 in the range of 50-1000 ng/mL, Limit of Detection (LOD) and Limit of Quantitation (LOQ) were 10 ng/mL and 30 ng/mL respectively, intra and inter-day deviations were lower than 3.92 % and 3.98 % respectively. The overall mean recovery of LAF was 94.57 %. No any endogenous constituents were found to interfere at retention time of the analyte. This new RP-HPLC method was successfully validated and may be applied to conduct bioavailability & bioequivalence studies of LAF.
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