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Now showing 1 - 4 of 4
  • Publication
    Development of a green high-performance liquid chromatography method for tofacitinib quantification in pharmaceutical formulations and degradation studies
    (2024-04-02) TIRIS G.; Genc A. A.; ERK N.; TIRIS, GİZEM
    A new high-performance liquid chromatography (HPLC) method was applied for the quantification of the active substance of tofacitinib. Analysis was performed on a Chromasil 100 C18 (100.0 x 4.0 mm, 3.5 mu m) stationary phase. The mobile phase consisted of acetonitrile:0.2% phosphoric acid in water (12:88, v/v). The prepared sample (20.0 mu L) was injected into the system. A detection wavelength of 285.0 nm was chosen for the compound, and the flow rate was 0.8 mL/min. The experiment was completed in 5.0 min. The analysis temperature was set to 40.0 degrees C. The method was evaluated using green chemistry. The method was validated according to the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines. For linearity studies calibration curves were constructed in the range of 10.0-200.0 mu g/mL. The recovery values were calculated at 97.66% and 105.68%. The method developed for the analysis of the active substance had a short analysis time and was cost-effective. It is an environmentally friendly method due to the mobile phase content used. The technique can be used in laboratory analysis and bioequivalence experiments.
  • Publication
    Fabric phase sorptive extraction combined with high performance liquid chromatography for the determination of favipiravir in human plasma and breast milk
    (2023-01-01) TIRIS G.; Gazioglu I.; Furton K. G.; Kabir A.; Locatelli M.; TIRIS, GİZEM; GAZİOĞLU, IŞIL
    A fast procedure obtained by the combination of fabric phase extraction (FPSE) with high performance liquid chromatography (HPLC) has been developed and validated for the quantification of favipiravir (FVP) in human plasma and breast milk. A sol-gel polycaprolactone-block-polydimethylsiloxane-block-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated on 100% cellose cotton fabric was selected as the most efficient membrane for FPSE in human plasma and breast milk samples. HPLC-UV analysis were performed using a RP C18 column under isocratic conditions. Under these optimezed settings, the overall chromatographic analysis time was limited to only 5 min without encountering any observable matrix interferences. Following the method validation pro-cedure, the herein assay shows a linear calibration curve over the range of 0.2-50 mu g/mL and 0.5-25 mu g/mL for plasma and breast milk, respectively. The method sensitivities in terms of limit of detection (LOD) and limit of quantification (LOQ), validated in both the matrices, have been found to be 0.06 and 0.2 mu g/mL for plasma and 0.15 and 0.5 mu g/mL for milk, respectively. Intraday and interday precision and trueness, accordingly to the International Guidelines, were validated and were below 3.61% for both the matrices. The herein method was further tested on real samples in order to highlight the applicability and the advantage for therapeutic drug monitoring (TDM) applications. To the best of our knowledge, this is the first validated FPSE-HPLC-UV method in human plasma and breast milk for TDM purposes applied on real samples. The validated method provides fast, simple, cost reduced, and sensitive assay for the direct quantification of favipiravir in real biological matrices, also appliyng a well-known rugged and cheap instrument configuration.
  • Publication
    Low-cost voltammetric sensor based on reduced graphene oxide anchored on platinum nanoparticles for robust determination of Favipiravir in real samples
    (2023-01-01) Bouali W.; ERK N.; Kholafazadehastamal G.; Naser M.; TIRIS G.; TIRIS, GİZEM
    © 2022 Elsevier B.V.This research describes a simple, sensitive, and disposable modified glassy carbon electrode constructed using platinum nanoparticles anchored on reduced graphene oxide nanocomposite as a conductive modifier (Pt@rGO/GCE) to detect an anti-coronavirus drug, Favipiravir (FAV). The as-synthesized nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). Under optimized conditions, the square wave voltammetry (SWV) method was used to determine trace amounts of FAV in real samples. The proposed electrode demonstrated a wide linear concentration range of 3.16 to 100.0 μM with a low detection limit (LOD) of 2.46 μM. Moreover, the developed electrode showed outstanding selectivity in the presence of several interferences with high repeatability and reproducibility. Finally, the developed electrode was applied to detect FAV in human plasma and pharmaceutical samples.
  • Publication
    Simultaneous analysis of sacubitril and valsartan by novel analytical methods with green approach
    (2024-04-01) TIRIS G.; Ayse Genc A.; ERK N.; TIRIS, GİZEM
    A novel high performance liquid chromatography (HPLC) and spectrophotometric analysis were applied for quantification of active substances of sacubitril (SAC) and valsartan (VAL). HPLC experiments were conducted on the Waters Spherisorb® (3.0 µm 60.0x4.0 mm) column. Preparation of mobile phase A: 200 mL of 0.1 % solution of trifluoroacetic acid in water and 800 mL of 0.1 % solution of trifluoroacetic acid in acetonitrile by volume are mixed. Preparation of mobile phase B: 800 mL of a 0.1 % solution of trifluoroacetic acid in water and 200 mL of 0.1 % solution of trifluoroacetic acid in acetonitrile by volume were mixed. It was given to the system at the ratio of Mobile Phase A: Mobile Phase B (35:65 v:v). The specimen was injected into the column at 15.0 µL. A detection wavelength of 254.0 nm was preferred for the compound and the flow rate was 2.0 mL/min. Analysis was completed in 4.0 min. The column oven temperature was adjusted to 40.0 °C. The methods were evaluated in terms of green chemistry. The methods have been validated according to ICH guidelines. For HPLC method calibration graphs were constructed in the 20.0– 145.0 and 20.0 – 155 µg/mL SAC and VAL respectively with an R2 of 1.000. In recovery experiments, the RSD values were calculated to be 0.08 % and 0.34 % for SAC and VAL, respectively. Additionally, in intraday and interday experiments, percent RSD values were found to be between 0.23 and 0.49. The method developed for the analysis of the active substances has been developed with a short analysis time and is cost effective. SAC and VAL were determined using a novel method for spectrophotometric analysis. The determination was performed simultaneously using the applied method. This method is a constant center method. Calibration graphs were constructed in the 2.0– 20.0 and 2.0 – 25 µg/mL SAC and VAL with an R2 of 0.9998 and 0.9999 respectively. It is a greenness method in terms of the analysis time and solvent used.