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- Author or Editor: Ahmad Adnan x
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A simple and sensitive high-performance thin-layer chromatographic (HPTLC)-densitometric method was developed for the simultaneous quantification of two flavonoid compounds, persicogenin and homoeriodictyol, in the methanol extracts of the aerial parts of two species (Rhus retinorrhoea and Rhus tripartita) of the genus Rhus grown in the Kingdom of Saudi Arabia. Chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates using toluene-ethyl acetate-methanol (8:2:0.5, v/v) as the mobile phase. Scanning and quantification were done at 293 nm. The system was found to give compact spot for homoeriodictyol and persicogenin at, R
F = 0.30 ± 0.01 and 0.48 ± 0.01, respectively. The linearity ranges for homoeriodictyol and persicogenin were found to be the same (100–800 ng spot−1) with correlation coefficients (r
2 values) of 0.9989 and 0.9983, respectively. The limit of detection (LOD) for homoeriodictyol and persicogenin was found to be 26 and 31 ng band−1, respectively, while the limit of quantification (LOQ) was found to be 77 and 92 ng band−1, respectively. Homoeriodictyol (7.06%) and persicogenin (2.33%) were only found in R. retinorrhoea. The developed method was found to be accurate and precise; hence, it can be used as an important tool to assure the therapeutic dose of homoeriodictyol and persicogenin in herbal formulations as well as for the standardization and quality control of bulk drugs.
The present work aimed to develop and validate a simple, rapid, sensitive, accurate, and precise method for simultaneous determination of metformin hydrochloride and vildagliptin in tablet and biological samples. Isocratic elution of both the analytes was performed at 35 °C by injecting 20 μL into Thermo Hypersil ODS C18 column (5 μm, 4.6 mm× 250 mm), while the flow rate was set to 0.8 mL/min. The mobile phase comprised of methanol, acetonitrile, and phosphate buffer (5:30:65, v/v, pH 3.5), and wavelength was selected at 212 nm. The overall run time per sample was 7.0 min with a retention time of 3.36 and 5.41 min for metformin hydrochloride and vildagliptin, respectively. The calibration curve was linear from 10–140 μg/mL for metformin and 1–14 μg/mL for vildagliptin with a coefficient of determination (R 2) ≤ 0.9919, while repeatability and reproducibility (expressed as relative standard deviation) were lower than 1.13 and 0.97%, respectively. Force degradation studies indicated a complete separation of the analytes in the presence of their degradation products providing a high degree of method specificity. The proposed reversed-phase high-performance liquid chromatography (RP-HPLC) method was demonstrated to be simple and rapid for the determination of metformin hydrochloride and vildagliptin in commercially available tablet and biological samples providing recoveries ranged between 100.13–100.29%.
