Chromatographia最新文献

Green tea has gained the global recognition for its health-promoting bioactive components such as rutin, caffeic acid, chlorogenic acid, and caffeine. With increasing consumer demand and rising concerns over product authenticity and adulteration, this study presents a qualitative high-performance thin-layer chromatography (HPTLC) for profiling these four marker compounds in five commercially available green tea products compared against a botanical reference material (BRM). The HPTLC method was developed for identifying these compounds using a mobile phase mixture of ethyl acetate, methanol, water, and formic acid (50:4:4:2.5). Additionally, physiochemical differences of green tea samples were also studied, including colour, texture, pH, and solubility in water, providing further insights into product quality and authenticity. This approach contributes to the utility of qualitative HPTLC as a cost-effective, rapid screening tool for standardization and quality control of green tea formulations. The findings are precise and relevant, supporting regulatory and consumer safety to ensure the integrity of green tea supplements in a growing global market.

Accurate quantification of antidiabetic drugs within biological matrices is essential for pharmacokinetic, pharmacodynamic, and therapeutic monitoring. Internal standards (ISs) play a pivotal role in ensuring the precision, accuracy, and reproducibility of bioanalytical assays by compensating for matrix effects, instrumental fluctuations, and inconsistencies in sample preparation. This review systematically examined 73 research articles to discern trends in IS selection, extraction techniques, biological fluid distribution, and analytical methodologies employed for quantifying antidiabetic drugs. The study elucidates the rationale behind IS selection, including the utilization of stable isotope-labeled (SIL) compounds, structurally related drugs, and deuterated analogs, which enhance the reliability and robustness of the method. Furthermore, the review underscores the significance of optimizing sample preparation techniques, such as protein precipitation (PP), liquid–liquid extraction (LLE), and solid-phase extraction (SPE), to improve analyte recovery. Advanced chromatographic and mass spectrometric techniques, particularly LC–MS/MS and HPLC/UPLC–MS/MS, provide high sensitivity and specificity along with broad calibration ranges, facilitating precise drug concentration measurements. These findings highlight the necessity for standardized IS selection criteria and refined bioanalytical methodologies to ensure reliable quantification across diverse biological fluids. By addressing existing challenges and proposing best practices, this review contributes to the advancement of bioanalytical research in diabetes management, aiding the optimization of pharmacokinetic studies and therapeutic monitoring of diabetes. The insights presented herein are crucial for enhancing the accuracy of drug quantification, thereby facilitating improved clinical decision-making and the development of more effective antidiabetic therapies.

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Resmetirom (RMT), a new drug approved for the treatment of metabolic dysfunction-associated steatohepatitis and the present work describes the development and validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) method for the quantification of RMT. The technique utilizes a Kromasil C18 column with mobile phase Acetonitrile and Ammonium acetate buffer (pH 3.5) in a 70:30 ratio, flow rate 0.8 mL min⁻¹, and UV detection at 298 nm. The process was validated as per the ICH Q2 (R2) guidelines, exhibiting specificity, linearity (5–30 µg mL⁻¹, R² = 0.9951), precision (RSD < 2%), accuracy (98–102% recovery), LOD of 0.214 µg mL⁻¹, and LOQ of 0.651 µg mL⁻¹. The method is applicable to the active pharmaceutical ingredient (API) and was successfully validated to estimate RMT content present in tablets prepared in-house. The proposed analytical method was evaluated for environmentally friendliness, assessed qualitatively and quantitatively using AGREE, cGAPI, AGREEPrep, and MoGAPI software. The validated RP-HPLC method gives a good and efficient means for quantifying RMT, is cost saving and time efficient thereby applicable in pharmaceutical quality control and analysis.

A stability-indicating high-performance liquid chromatographic (HPLC) method for Vibegron (VBG) was developed and validated based on the analytical quality-by-design (AQbD) concept. Screening of critical factors were studied using risk assessment, followed by Plackett–Burman design, and optimization of critical factors were done using an I-optimal response surface design. The optimized chromatographic conditions include a Kromasil Classic C18 column (250 × 4.6 mm, 5 µm) and a mobile phase consisting of acetonitrile (A) and 10 mM ammonium acetate buffer pH adjusted to 4.5 with trifluoroacetic acid (B); in a ratio of (A:B; 46:54 v/v) ratio, at a flow rate of 0.8 mL/min, with a detection wavelength of 248 nm. The method has been validated as per ICH guidelines and demonstrated linearity (R² > 0.997), precision (% RSD < 2), and accuracy (99.97 ± 1.61% recovery). VBG was found to be sensitive during stress testing under various environmental conditions, including hydrolytic, oxidative, thermal, and photolytic stress. A total of 18 degradation products were separated, identified, and quantified using the developed method. The method's sustainability was assessed using the Whiteness assessment via the RGB 12 algorithm, the Analytical GREEness Tool (AGREE), the Complex Green Analytical Procedure Index, and the Blue Applicability Index, ultimately confirming that it is both green and practical. The developed method can be applied in pre-formulation studies, quality control, and pharmacovigilance.

Pyrantel is used as an active pharmaceutical ingredient (API) in both human and veterinary drug products. It is widely available as pyrantel pamoate (PP) and is also referred to as pyrantel embonate. It acts as a depolarizing neuromuscular blocking agent, causing paralysis in parasitic worms (helminths). The objective of this work was to develop an efficient, selective, and robust reversed phase high-performance liquid chromatography (RP-HPLC) method to determine PP and its related impurities in bulk API batches. The new method utilizes a Waters Xselect®HSS T3 column (100 mm × 4.6 mm i.d., 2.5 μm particle size) at 30 °C, with 0.1% TFA in H2O as mobile phase A and 100% methanol as mobile phase B. Analytes were separated by gradient elution at a flow rate of 1.0 mL/min and were detected by UV at 280 nm, except for impurity D (at 215 nm). The total run time of the method is 18 minutes. Unlike the PP methods prescribed in USP and Ph. Eur., the new HPLC method described in this paper adequately separates all peaks of interest and have demonstrated excellent robustness and reproducibility across various varied conditions. The results of forced degradation studies confirmed its stability-indicating capability. The validation results demonstrated that the new method is accurate, robust, specific, and stability-indicating. One of the key strengths and highlight of the new method is its capability in resolving the co-eluting peaks under the conditions of the USP/Ph. Eur. Methods.

An ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLME) technique with low LODs, high enrichment factors, and reduced solvent use was devised for the extraction and determination of multiclass pesticide residues in tomato samples. The extraction process uses acetone for the initial extraction of pesticides from tomatoes, followed by dispersive liquid–liquid microextraction using 1-hexyl-3-methylimidazolium hexafluorophosphate as the extraction solvent. The critical parameters that affect the extraction efficiency, such as the type and volume of the extraction solvent, the volume of the dispersive solvent, the type and volume of the ionic liquid, pH, and salt addition, were meticulously optimized. Under these optimized conditions, the method exhibited robust linearity (R² ≥ 0.9960), low limits of detection (2.0–7.3 µg/kg) and quantification (5.6–19.4 µg/kg), along with satisfactory precision (RSD ≤ 10.4%) and recovery rates (88.0 to 105.3%) for the pesticides of interest. The proposed method represents a promising tool for routine pesticide monitoring in food quality control laboratories.

The classical theoretical model of the field-flow fractionation, assuming the exponential concentration distribution of the species affected by the external fields in polarization mechanism, is just an approximation neglecting the possible formation of the organized structures. Original use of Riemann’s integral to calculate the dimensionless exponential concentration distribution enables to study the thermodynamic aspects and the related transport phenomena for model systems where the field forces are weak and to obtain precise and predictive results on the equilibrium positions of the species forming the focused zones by two different mechanisms. The samples injected into the separation units of the field-flow fractionation are rather diluted but the applied field forces transport the macromolecular or particulate species and produce the zones of much higher concentration. Consequently, the organized structures, that constitute the spacially oriented concentration gradients in the direction of the effective field forces, appropriate to each particular separation mechanism, may appear whenever the repulsive interactions among the dissolved or dispersed species restrict their free Brownian motion. It is difficult to detect the existence of such structures directly in thin field-flow fractionation channels but it was unquestionably proven by the small angle X-ray scattering of larger volume of the negatively charged nanometer sized particles in aqueous suspension of silica. The experimental equilibrium positions of the particles of different densities but almost the same size, focused by the action of lift forces, were identical, but their trajectories from the starting takeoff from the accumulation wall to the equilibrium positions were different. This finding inspired the idea to exploit this effect for rapid focusing micro-TFFF.

The purpose of the study was to synthesize bergapten-loaded nanostructured lipid carriers (NLCs) to characterize and develop an HPLC method. The bergapten-loaded NCLs were characterized for size, polydispersity index (PDI), and zeta potential (ZP). The morphology of NLCs was observed by scanning electron microscopy (SEM). The drug encapsulation and loading efficiency were evaluated. Moreover, an HPLC method was developed and validated in terms of accuracy, precision, specificity, linearity, limit of detection, and limit of quantitation. Bergapten-loaded NLCs exhibited a size of 23.5 nm with 0.25 PDI, confirming narrow size distributions, whereas blank NLCs showed 20.7 nm size and 0.19 PDI. The ZP of bergapten-loaded NLCs was − 13.0 mV, which was found to be almost the same as blank NLCs. SEM images confirmed the smooth surface and spherical shape of NLCs. The HPLC-validated method for drug quantification was found to be simple and efficient. Successful fabrication of drug-loaded NLCs showed size, PDI, and ZP within range with a smooth and spherical shape, and HPLC methods showed good estimation of bergapten in NLCs.

Microfluidic paper-based analytical devices (µPADs) are valued of their low cost and portability, making them perfect for testing at the point of need. Their adaptability in size and shape further improves their portability, detection and analysis that can be carried out with portable devices. µPADs meet the essential demand for quick, dependable and simple testing in diverse areas, such as environmental monitoring, healthcare and food safety. This review offers a thorough overview of the development of µPADs, exploring key design factors such as the type of paper utilized and the core operational principles. Key detection methods include colorimetry, fluorescence, and electrochemistry, with recent innovations combining optical and electrochemical techniques to improve sensitivity and selectivity. In addition, distance-based detection methods are emphasized for their ability to provide instrument-free analysis and minimize error, which is especially important in resource-limited settings. The review concludes by addressing the practical challenges and requirements of µPADs, providing valuable insights for future research and advancements in the field of analytical chemistry.

The determination of chloride in crude oil and its derivatives is a matter of utmost importance for the petroleum industry. In this study, we developed a straightforward methodology for chloride extraction for its determination in diesel oil. The extraction was performed using deionized water, employing microwave radiation as the energy source, and the quantification of chloride in the extracts was conducted by ion chromatography. The method was optimized using a multivariate approach through a Doehlert design. The optimized variables included sample mass (between 0.25 and 1.25 g), extraction time (between 5 and 35 min), and extraction temperature (between 100 and 150 °C). Only sample mass showed a significant effect on extraction efficiency, although the temperature used in the process could not exceed 150 °C to avoid sample degradation. Under the optimized conditions (0.25 g of sample in 10.00 mL of deionized water, maintained at 125 °C for 20 min), the limits of detection and quantification of the method were 0.24 µg g^–1 and 0.72 µg g^–1, respectively. It was successfully applied for chloride determination in six samples of both commercial and raw diesel oil. An average recovery rate of 94 ± 10% was obtained in the recovery assays.