Chromatographia最新文献

The aim of this study was to find lipid metabolite concentrations differences between healthy subjects and colorectal cancer patients. A novel high performance liquid chromatography–electrospray ionization tandem mass spectrometry (HPLC–ESI–MS/MS) analytical method was developed for the analysis of nine lipid series (two sphingolipids, seven phospholipids) using the multiple reaction monitoring mode (MRM) on dried plasma spots. The extracted lipids were separated by HPLC using an Imtakt Unison UK-C8. The developed method was applied to human plasma samples obtained from healthy subjects (n = 40) and colorectal cancer patients (n = 40). A partial least squares discriminant analysis (PLS-DA) model, which is a multivariate statistical analysis method, was employed to analyse the quantitative results. The VIP score of the PLS-DA model was employed to effectively discriminate colorectal cancer patients from healthy subjects. Furthermore, a random forest classification method was employed. Through statistical processing, the lipid 18:1 Lyso PC in accordance with VIP score > 1 was identified, and four lipids in accordance with p-value < 0.05, 15:0–18:1 PC, 18:1 Lyso PC, 18:1 Lyso PE, and C15 Ceramide (d18:1/15:0) were identified. The results of this study corresponded to study of Zhao et al.(2007) that 18:1 LPC can be potential biomarker between normal and colorectal cancer patients. This method is expected to be practically useful due to its simple dried plasma spot use and excellent sensitivity for lipid screening when applied to various diseases, including colorectal cancer.

The research presents a novel application of the QbD technique to develop and validate a stability-indicating method for terlipressin quantification in injection form, aligning with ICH Q2 (R2) guidelines using the HPLC method. Terlipressin, a synthetic drug recently approved by the FDA for treating hepatorenal syndrome, lacks an official monograph in any pharmacopeia, and the existing stability indicating methods for its quantification were limited. The primary objective is to establish a method using the QbD approach and ICH Q8 (R2) guidelines, emphasizing accuracy, simplicity, rapidity, and robustness. The method is optimized through the design of experiments, including response surface plots, contour plots, and overlay plots. Successful development of this method results in a shorter retention time (less than 4 min) using a SunFire C₁₈ column with dimensions 250 mm × 4.6 mm and particle size of 5µm, mobile phase consisting of acetonitrile and 0.1% orthophosphoric acid (11:89 v/v), flow rate of 1 ml/min, and the PDA detection at 216 nm, with an injection volume of 8 µl and a column heater temperature of 30 °C. This method’s total run time was 6 min, using water as a diluent. Forced degradation experiments have verified that the approach is stability-indicating for the terlipressin injection dosage form assay. The analytical method has demonstrated a linear response over the 0.25–1.5 µg/ml concentration range, exhibiting an R² of 0.9994 and recovery percentage was 99.09–100.43%.

Polygonati Rhizoma, as a traditional medicinal herb, possesses pharmacological effects enhancing physical strength and immunity. In this study, a systematic analysis of the monosaccharide and non-polysaccharides components in Polygonati Rhizoma was conducted using pre-column derivatization high-performance liquid chromatography (HPLC–DAD) and liquid chromatography coupled to electrostatic orbitrap high-resolution mass spectrometry (LC–Orbitrap-MS) techniques. The polysaccharides from Polygonati Rhizoma were initially extracted, hydrolyzed, and derivatized with 1-phenyl-3-methyl-5-pyrazolone (PMP), resulting in the successful detection of five monosaccharides. The high sensitivity and specificity of the HPLC–DAD method were confirmed. Furthermore, by comparing the external standard method (ESM) and the quantitative analysis of multi-components by single-marker (QAMS) revealed that D-mannose is the most abundant monosaccharide in Polygonati Rhizoma. The LC–Orbitrap-MS analysis of Polygonati Rhizoma led to the identification of 53 compounds, including organic acids, amino acids, amides, saponins, alkaloids, esters, and others. This research provided significant data for the chemical composition analysis and the pharmacological basis study of Polygonati Rhizoma.

The aim of this paper was to present a rapid, simple, and straightforward high-performance liquid chromatography (HPLC) method for the determination of robenacoxib in plasma. Robenacoxib is a member of the COXIB group of nonsteroidal anti-inflammatory drugs developed for veterinary use. The method was validated based on the FDA Guidance for Industry: Bioanalytical Method Validation for selectivity, linearity, accuracy, precision, stability, and recovery. Methylene chloride was used in a liquid–liquid extraction that produced an average recovery of 97%. Chromatographic separation occurred on a Sunfire C₁₈ column (4.6 × 150 mm) using an isocratic combination of 0.025% trifluoroacetic acid in water and acetonitrile (50:50, v/v). Ultraviolet absorbance was measured at 275 nm and the flow rate was 1.1 mL/min. The method was linear in the concentration range of 0.1 to 50 µg/mL. The assay variability ranged from 2.2% to 9.2% while the accuracy was 100%. The lower limit of quantification for a 0.1 mL sample size was 0.1 µg/mL. The method was used for the determination of robenacoxib in plasma samples.

The demand for novel flavors and fragrance (F&F) compounds has increased, highlighting the need for a systematic design approach. Currently, the F&F industry relies heavily on experimental approaches without considering the potential consequences of altering the features that contribute to the fragrance of the compound. In silico approaches have great potential to identify the necessary features for creating novel F&F compounds. In the present study, Quantitative Structure–Property Relationship (QSPR) models were developed using 1208 compounds and simple 2D descriptors, focusing on the RI (retention index) as the endpoint to predict the olfactory properties of molecules. Feature selection was initially carried out by multi-layered stepwise regression followed by feature thinning using the Genetic Algorithm (GA) and optimal feature combination selection using the BSS (best subset selection) method. Final models were developed using the Partial Least Squares (PLS) method. Additionally, internal and external validation of the models was performed using different validation metrics suggesting that the developed models are reliable, predictive, reproducible, and robust. To enhance the external prediction of the developed models, an Intelligent Consensus Prediction (ICP) method was employed and CM3 (consensus model 3) (best selection of predictions (compound-wise) from individual models) was found to provide the best predictivity. The modeling descriptors suggested that the hydrophobicity, high molecular weight, aromaticity, and presence of large-size fragments (high percentage of carbon) enhance the RI values. Conversely, polarity and hydrophilicity decrease the RI values. This study can be used to optimize the stationary phase according to the flavor and fragrance compounds to obtain the desired retention index (RI values).

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Violae herba (Zihuadiding) is a common Chinese herbal medicine. The current Chinese Pharmacopeia (ChP) defines Viola yedoensis Makino as the sole plant origin and esculetin as its sole quality-marker (Q-marker). Esculetin, however, occurs in some counterfeits as well. This implies that current ChP criterion actually cannot recognize the counterfeits of V. yedoensis. The study thus created a specialized MS library using ultra-high-performance liquid chromatography with quadrupole-orbitrap tandem mass spectrometry (UHPLC-Q-Orbitrap-MS/MS) analysis. Through library-comparison, 36 compounds were putatively identified from V. yedoensis; especially, four isomers were successfully distinguished, that is, vitexin vs isovitexin and schaftoside vs isoschaftoside. The subsequent UHPLC-Q-Orbitrap-MS/MS semi-quantification suggested that the chemical contents of 36 compounds varied from 0.001 to 1.958% and the old Q-marker esculetin had high content (0.484 ± 0.028%). According to the relevant principles, flavonoid luteolin was proposed as the new and additional Q-marker. The proposal offers a preliminary evidence to recognize seven adulterations (or counterfeits) of V. yedoensis.

Helicobacter pylori (H. pylori) infection is one of the primary risk factors of peptic ulcer disease worldwide. Treatment of H. pylori with the conventional dosage form is often challenging due to the ineffective reach of the antibiotics to the inner layers of gastric mucosa, where the organism resides. This study developed an eco-friendly, stability-indicating RP-HPLC method to simultaneously estimate amoxicillin and tinidazole from mucoadhesive formulation targeting H. pylori infection. The mucoadhesive GRDDS formulation of antibiotics was developed with a goal of improving bioavailability at the gastric mucosa. The multivariate Box–Behnken design (BBD) was utilized to optimize chromatographic parameters. Independent variable such as ratio of mobile phase, flow rate, pH and injections volume were optimized using DoE, and analyzed using perturbation plots. A desirability of 0.981 was achieved for the optimized variables. The optimized method utilized methanol and phosphate buffer (25:75) at pH 6.3 as the mobile phase in an isocratic elution mode on a Luna ODS C18 column kept at 25 °C as the stationary phase. The method was linear from 0.25 to 20 µg/mL, for both the drugs with R² values of 0.9993 and 0.9997 for amoxicillin and tinidazole, respectively. This validated RP-HPLC technique demonstrated selectivity in the presence of possible degradation products and excipients present in the mucoadhesive GRDDS beads. The method was used for the determination of entrapment efficiency and in vitro release profile for tinidazole and amoxicillin in the mucoadhesive GRDDS formulation.

Graphical Abstract

Chitosan is a chiral polyglucosamine polysaccharide that selectively binds to S-enantiomer of ketorolac rather than R-enantiomer. In this paper, a novel chiral stationary phase was prepared by molecular imprinting of chitosan using racemic ketorolac as a template. This imprinting process resulted in a high enantioselectivity (59.66% ee and enantioselectivity coefficient of 2.6) as evaluated by the batch rebinding study. The prepared stationary phase enabled chiral resolution of racemic ketorolac when packed into a solid-phase extraction cartridge. Moreover, promising results were obtained when an HPLC column packed with the proposed stationary phase was tested for chiral separation. The selectivity factor (α) was calculated to be 5.3 indicating the enantioselectivity of the prepared stationary phase. The chromatographic resolution trials revealed a mixed hydrophilic interaction liquid chromatography (HILIC) and reversed-phase (RP) separation modes in addition to the imprinted cavities. These results showed that racemic compounds could be cheaper and more available templates for imprinting of enantioselective polymers for chiral stationary phases.