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Development and validation of a reversed-phase HPLC method for simultaneous determination of doxazosin mesylate and finasteride

Krotz D., Mengesha A. E.

Acta Chromatographica

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2017

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Vol. 29, no. 3

309--324

EN

A reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous determination of doxazosin mesylate (DOX) and finasteride (FIN) in bulk powders and pharmaceutical formulations. The compounds were separated on a Pinnacle II C18 column (250 × 4.6 mm i.d.; particle size, 5 μm) with an isocratic mobile phase at a flow rate of 1.0 mL min−1. The mobile phase was a mixture of 25 mM ammonium acetate and acetonitrile in the ratio of 50:50 %v/v. The pH of the buffer was adjusted to 4.0 ± 0.05 with glacial acetic acid. The detection was performed at 230 nm. The total chromatographic analysis time per sample was 15 min with DOX and FIN eluting at 3.9 and 7.2 min, respectively. The accuracy, precision, specificity, linearity, and sensitivity of the method were validated according to the International Conference on Harmonization (ICH) guidelines. The calibration plots were linear (r2 > 0.999) over the concentration range 24.25–291.0 μg mL−1 and 122.5–1470.0 μg mL−1 for DOX and FIN, respectively. The method was used for the simultaneous determination of DOX and FIN in capsules.

2

Identification and simultaneous determination of glycyrrhizin, formononetin, glycyrrhetinic acid, liquiritin, isoliquiritigenin, and licochalcone A in licorice by LC-MS/MS

Xie J., Zhang Y., Wang W., Hou J.

Acta Chromatographica

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2014

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Vol. 26, no. 3

507--516

EN

A new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous determination of glycyrrhizin, formononetin, glycyrrhetinic acid, liquiritin, isoliquiritigenin, and licochalcone A in licorice. An Eclipse Plus C18 column (I.D. 4.6 × 100 mm, 3.5 μm particle size; Agilent) was used in the analysis. Electrospray ionization (ESI)-tandem interface in the negative mode was performed, and multiple reaction monitoring (MRM) was employed with the precursor multiple reaction monitoring production combination for the determination of six analytes. The average recoveries ranged from 98.30% to 100.13% with relative standard deviations (RSDs) ≤ 1.95%, and limits of detection (LODs) ranged from 2.1 to 3.6 pg. The applicability of this analytical approach was confirmed by the successful analysis of six samples. The results indicated that the established method was validated, sensitive, and reliable for the determination of six analytes in licorice.

3

Validated HPLC method development for simultaneous analysis of withaferin-A and 6-gingerol

Jain V., Thakur A, Soman G, Laddha K. S.

Acta Chromatographica

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2010

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Vol. 22, no. 1

153--159

EN

A simple, rapid, and specific reversed-phase HPLC method has been developed for simultaneous analysis of withaferin-A and 6-gingerol in a polyherbal formulation containing Withania somnifera and Zingiber officinalis extracts. HPLC analysis was performed on a C 18 column using a 40:60 ( v / v ) mixture of acetonitrile and water as isocratic mobile phase at a flow rate of 1.5 mL min −1 . UV detection was at 227 nm for withaferin-A and 278 nm for 6-gingerol. The method was validated for accuracy, precision, linearity, specificity, and sensitivity in accordance with International Conference on Harmonization guidelines. Validation revealed the method is specific, accurate, precise, reliable and reproducible. Good linear correlation coefficients ( r 2 > 0.9996) were obtained for calibration plots in the ranges tested. Limits of detection were 0.2 and 0.4 μg and limits of quantification were 0.5 and 1.0 μg for withaferin-A and 6-gingerol, respectively. Intra and inter-day RSD of retention times and peak areas were less than 2.1%. Recovery was between 94.5 and 98.8% for withaferin-A and 94.2 and 102.4% for 6-gingerol. The established HPLC method is appropriate and the two markers are well resolved, enabling efficient quantitative analysis of withaferin-A and 6-gingerol. The method was successfully used for quantitative analysis of these two marker constituents in a marketed polyherbal formulation.

4

An RP-HPLC method for simultaneous analysis of, and interaction studies on, enalapril maleate and H 2 -receptor antagonists

Sultana N., Arayne M. S., Naveed S., Shamshad H

Acta Chromatographica

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2009

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Vol. 21, no. 4

547--558

EN

A simple, sensitive, and rapid RP-HPLC method for analysis of enalapril in the presence of H 2 -receptor antagonists has been developed and validated. Enalapril maleate was separated from H 2 -receptor antagonists by use of a 250 mm × 4.6 mm, 5-µm particle, C 18 column with 86:14 ( υ / υ ) methanol-water, pH adjusted to 3.5, as mobile phase, at a flow rate of 1.5 mL min -1. UV detection was performed at 227 nm. The retention times of enalapril maleate, ranitidine, cimetidine, and famotidine were 3, 5, 7, and 7.5 min, respectively. The detection limit for enalapril was 10 ng mL -1 and the calibration plot was linear in the range 2.5–50 µg mL -1. In-vitro interaction of enalapril with the commonly administered H 2 -receptor antagonists cimetidine, ranitidine, and famotidine in simulated gastric juice at different pH and 37°C was also studied by use of this method. These studies clearly indicated that most of these H 2 -receptor antagonists bind to enalapril causing drastic changes in the availability of the drug. The HPLC method is accurate, selective, sensitive, and reproducible.

5

Joint analysis of histological and ultrasonic images to lean state of thyroid gland

Nedzved A., Zalesky B., Ablameyko S., Drozd V., Fridman M.

Machine Graphics and Vision

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2007

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Vol. 16, No. 3/4

293-304

EN

Simultaneous analysis of histological and ultrasonic (US) images of human thyroid glands for thyroid cancer diagnostics is proposed in the paper. It allows to explain the characteristics of US pictures of the thyroid gland via the sizes of its follicles. To show the dependence of US image features on the state of follicles, statistical analysis of US-texture is performed. In addition, the size of follicles in histological images is calculated by analysis of a distance map for the nuclei of cells. It is shown that echogenicity of the thyroid gland in US images depends essentially on the size of its follicles. The organ regions that contain many follicles of a size smaller than the size of healthy follicles, or contain many destroyed follicles, have low echogenicity. The same effect is observed for regions with oversized follicles. This information can be used to avoid a surgical procedure, including histological analysis.