High-performance Liquid Chromatography-ultraviolet Research Articles

Simultaneous determination of six catechins and caffeine in tea and wine using salting-out assisted liquid-liquid extraction and high-performance liquid chromatography with ultraviolet detection.

Catechins, renowned for their antioxidant properties and health benefits, are commonly present in beverages, particularly tea and wine. An efficient and cost-effective salting-out assisted liquid-liquid extraction (SALLE) method has been developed and validated for the simultaneous determination of six catechins and caffeine in tea and wine samples using high-performance liquid chromatography-ultraviolet (HPLC-UV). This method demonstrates outstanding performance: linearity (1-120µg/mL, r2>0.999), accuracy (96.5%-103.4% recovery), and precision (≤14.7% relative standard deviation), meeting validation requirements set by the US Food and Drug Administration. The reduced sample size (0.1g) minimizes matrix interferences and costs without compromising sensitivity. All analytes were detected in Camellia sinensis teas, with green tea displaying the highest total catechin content (47.5-100.1mg/mL), followed by white and black teas. Analysis of wine samples reveals the presence of catechin in all red and white wines, and epigallocatechin gallate in all red wine samples, highlighting the impact of winemaking processes on catechin content. The SALLE-HPLC-UV approach represents a green alternative by eliminating organic waste, surpassing conventional dilution methods in specificity and sensitivity for catechin determination. AGREEprep assessment emphasizes the strengths of the SALLE procedure, including material reusability, throughput efficiency, minimal sample requirements, low energy consumption, and the absence of organic waste generation.

Development, optimization and validation of an analytical method for the determination of Voriconazole in plasma by High-Performance Liquid Chromatography-Ultraviolet detection: Application for comprehensive Study

Voriconazole is a widely used antifungal agent in clinical settings. However, its use has been associated with neurological side effects in some patients. For this reason, it is crucial to monitor its plasma levels to ensure that they are within the therapeutic range. Thus, in this study, we aimed to develop a simple, fast, and efficient method for the determination of voriconazole in plasma using reversed-phase HPLC-UV. We also aimed to validate the method for its application to routine analysis of immunocompromised patients. Plasma samples from immunocompromised patients were subjected to deproteinization with acetonitrile followed by centrifugation. Chromatographic separation was carried out on a C18 column with UV detection at 254 nm in isocratic mode. The concentrations were calculated by comparing peak areas to those of the internal standard, ketoconazole. The method was validated using the accuracy profile, which uses a calibration curve established for the therapeutic range of 1 to 5.5 µg/mL. The developed method was proved to be rapid by giving a short analysis time for voriconazole at around 5.5 min. Additionally, no interference with the biological matrix was detected. The obtained recoveries were higher than 90%. The accuracy profile showed that the method was accurate and precise for the determination of voriconazole in plasma. The developed method was proved to be simple, efficient, that requires minimal sample preparation. Thus it can be routinely applied for the therapeutic monitoring of voriconazole.

High-performance liquid chromatography (HPLC) as a means of assessing the presence of uric acid in archeological human remains: Challenges and future directions.

This research aimed to replicate the Swinson, D., Snaith, J., Buckberry, J., & Brickley, M. (2010). High performance liquid chromatography (HPLC) in the investigation of gout in paleopathology. International Journal of Osteoarchaeology, 20, 135-143. https://doi.org/10.1002/oa.1009 method for detecting uric acid in archeological human remains to investigate gout in past populations and to improve the original High Performance Liquid Chromatography-ultraviolet (HPLC-UV) method by using HPLC-mass spectrometry (HPLC-MS), a more sensitive, compound-specific detection method. We used reference samples of uric acid to create a dilution series to assess the limits of quantification and detection. Samples from individuals with and without gout lesions were taken from foot bones and ribs from the English cemeteries of Tanyard, Hickleton, Gloucester, and Lincoln. We could not replicate the results of Swinson and colleagues using HPLC-UV. Tests using a dilution series of uric acid showed HPLC-MS was approximately 100× more sensitive than HPLC-UV, with the additional benefit of being compound specific. A newly developed hydrophilic interaction chromatography (HILIC) method improved retention characteristics. Fourteen samples from eight individuals, five with skeletal lesions consistent with gout, were analyzed with the final method. None showed evidence of uric acid despite the newly developed method's improved sensitivity and specificity. The lack of detectable uric acid extracted from these samples suggests that (1) urate crystals were not present in any of the bone samples, regardless of gout status; (2) urate crystals did not survive these specific archeological conditions; or (3) the concentration of uric acid in our bone extracts was low, and thus larger samples would be required.

Simultaneous high-performance liquid chromatography analysis of anthraquinones in sicklepod sprouts with α-glucosidase inhibitory activity.

Sicklepod [Cassia obtusifolia L. syn Senna obtusifolia (L.) H.S. Irwin & Barneby, Fabaceae] sprouts are promising ingredients with health-promoting benefits. Notwithstanding, the pharmacologically active compounds in sicklepod sprouts have not been studied or analysed in detail. This study aimed to isolate and structurally identify phytochemicals showing α-glucosidase inhibitory activity in sicklepod sprouts and simultaneously quantify the compounds in the sprouts to determine the optimal cultivation method and germination time to maximise active compounds. A simultaneous high-performance liquid chromatography-ultraviolet (HPLC-UV) method with high sensitivity and accuracy was developed and used to analyse time-dependent changes in anthraquinone content during sicklepod germination. Thirteen anthraquinones were isolated and identified, of which six-chrysoobtusin, emodin, 1-O-methyl-2-methoxychrysophanol, 7-O-methylobtusin, chrysophanol, and physcion-showed moderate α-glucosidase inhibitory activity. The maximum content of anthraquinones in a sprout was observed on Day 5 under both light and dark conditions. The findings of this study revealed that sicklepod sprouts which are promising functional food materials contain a variety of anthraquinones.

Dispersive liquid–liquid microextraction based on deep eutectic solvent followed by high-performance liquid chromatography-ultraviolet for imidacloprid, hexythiazox, and fenpyroximate determination: Experimental design approach

Dispersive liquid–liquid microextraction (DLLME) of three insecticides, including imidacloprid (I), hexythiazox (H), and fenpyroximate (F), was performed as an efficient method for separation and preconcentration using a deep eutectic choline chloride-acetic acid solvent (DES) followed by determination by high-performance liquid chromatography-ultraviolet (HPLC-UV). The experimental design approach (central composite design) was used to optimize the effective parameters. According to the results, the addition of salt had no significant effect on extraction among the four parameters studied, including pH, DES volume (dispersive solvent), salt concentration, and chloroform volume. The optimized conditions in the DES-DLLME-HPLC-UV method were pH = 6.00, 100 µL DES, and 138 µL chloroform. Under optimized conditions, a wide linear range of 1.00 × 10-3-20.00 µg mL−1 was obtained for three insecticides. The enhancement factors were 11.22, 58.04, and 39.65 and the limit of detection of 3.00 × 10-4, 2.00 × 10-4, and 2.00 × 10-4 µg mL−1, and the limit of quantification of 9.00 × 10-4, 8.00 × 10–4, and 6.00 × 10-4 µg mL−1 were also determined for imidacloprid, hexythiazox, and fenpyroximate, respectively. The presence of other components including benomyl, dimethoate, mancozeb, captan, thiodicarb, carbendazim, and oxyfluorfen, showed no significant interference effect on the determination of three insecticides in terms of retention times up to 50-fold. The method is eco-friendly benign, sensitive, precise, and straightforward as shown by the results.

Application of solid-phase extraction materials from ion liquids for the analysis of carbamate pesticide

In this study, ionic liquid immobilised onto silica gel material SiO2-(CH2)3-N(Oct)3Br was successfully synthesised and characterised by Fourier-transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). This material was applied as the stationary phase of solid-phase extraction for the enrichment of trace amounts of carbamate pesticides in water. The cartridge was eluted with 5 ml of acetonitrile (ACN), blow-dried with nitrogen gas, and re-dissolved in ACN:H2O (40:60, v/v) and analysed by high-performance liquid chromatography - ultraviolet (HPLC-UV) at 210 and 245 nm. Within this process, elution of the cartridge with 5 ml of acetonitrile (ACN) was followed by nitrogen gas blow-drying and subsequent re-dissolution in ACN:H2O (40:60, v/v), culminating in analysis by HPLC-UV at 210 and 245 nm. Optimisation of conditions facilitated the analysis of carbamate pesticides, with the limit of quantitation (LOQ)ranging from 0.36-2.00 μg/l for tap water and 0.4-3.5 μg/l for river water. Furthermore, the method exhibited favourable repeatability, with a relative standard deviation (RSD) of less than 10%, thereby meeting the Association of Official Analytical Collaboration (AOAC) standards.

Easy and fast synthesis of MnCo-LDH yolk-shell spheres porous composites applied electrospinning nanofibers highly effective for extracting triazole fungicides

Today, the wide utilization of triazole fungicides due to environmental damage and its side effects has raised global concern. Thus, in this investigation, polyacrylonitrile/MnCo-layered double hydroxides nanofiber was synthesized and applied as an effective and novel adsorbent at thin-film solid-phase micro-extraction technique for the quick and concurrent extraction of five triazole fungicides in fruit and vegetable samples before quantitative analysis by high-performance liquid chromatography-ultraviolet. The incorporation of MnCo-layered double hydroxides with porous structure and abundant functional groups in a polymer medium improves the extraction efficiency of nanofibers owing to hydrogen bonding and π-π interactions formed between analytes and synthesized nano-adsorbent. Various important elements that affect the extraction efficiency of the intended analytes were optimized using a time-variable approach. Under the optimum conditions, the limit of detection and quantification range from 0.1 to 0.15 and 0.3–0.5 ng mL−1, respectively.

Development and Validation of a New High-Performance Liquid Chromatography-Ultraviolet Assay for Quantification of Mitoxantrone in Plasma of BALB/c-nu Mice.

The concentration of mitoxantrone in the blood of mice was determined by a high-performance liquid chromatography-ultraviolet method with aloe-emodin as the internal standard. The separation was performed on a Hypersil BDS2 column (4.6 × 250mm, 5μm) as the analytical column, the mobile Phase A was acetonitrile, and B was 20-mM potassium dihydrogen phosphate (adding 1% triethylamine and adjusting the pH to 2.8 with phosphoric acid) and 4.6-mM sodium octyl sulfonate. The flow rate was 1.0mL·min-1, the detection wavelength was 243nm, the column temperature is 25 ± 5°C and the injection amount was 20μL. Finally, the linear range of mitoxantrone was 5-200μg·mL-1, and the correlation coefficient was r = 0.9999. The recovery rate of the method was 91.93-105.5%, and the extraction recovery rate was 91.45-105.5%. The intraday precision and interday precision were <3.29% (limit of detection = 0.3μg·mL-1). The HPLC method established in this paper was simple, rapid, sensitive and accurate, and can be used to determine the content of mitoxantrone in mouse plasma after tail vein injection.

Terpenes based hydrophobic deep eutectic solvents for dispersive liquid-liquid microextraction of aliphatic aldehydes in drinking water and alcoholic beverages

Aliphatic aldehydes are a class of organic compounds containing aldehyde groups, which are widespread, and closely related to people's daily life and health. In this work, a series of terpenes based hydrophobic deep eutectic solvents were designed and synthesized using hexafluoroisopropanol as hydrogen bond donor and menthol/thymol as hydrogen bond acceptor. Then they are used as extraction solvent in dispersive liquid-liquid microextraction for extracting and determining seven aliphatic aldehydes from drinking water and alcoholic beverage combined with high performance liquid chromatography-ultraviolet. Due to the fact that these hydrophobic deep eutectic solvents are liquid at the room temperature, a density greater than that of water, a lower viscosity (≤26.10 mPa s, 25 °C), after extraction and centrifugation, the microvolume DES-rich phase in the bottom is convenient for collection and direct analysis without further dissolution or dilution with organic solvents. Some factors affecting the extraction recovery were optimized by one-variable-at-a-time and response surface methodology. Under the optimal conditions, the enrichment factors for the seven aliphatic aldehydes were 48–56. The method had good performance: linear ranges of 1.0–200, 0.5–200, 0.2–200, 0.4–400, 1.0–400, 0.4–400 and 0.4–400 μg L−1 for seven aliphatic aldehydes (r2 ≥ 0.9949), limits of detection of 0.1–0.5 μg L−1, intra-day and inter-day precisions <4.9%. The recoveries of seven aliphatic aldehydes ranged from 76.0 to 119.0%. The proposed dispersive liquid-liquid microextraction method is simple, rapid, highly efficient, and green, which effectively reduces the amount of toxic chemical reagents used and their impact on the environment. Rapid and efficient detection of aliphatic aldehydes helps ensure a healthy diet and has great application prospects in food safety analysis.

Phytochemical and physicochemical studies of different apple varieties grown in Morocco

Abstract The apple is an important part of the human diet and is one of the most popular fruits in Morocco, with varieties that are now suitable for human consumption. This study aims to clarify several aspects of apples, such as their physical and chemical compositions and nutrient profiles. Total polyphenols, flavonoids, tannins, and anthocyanins were determined using spectrophotometer and organic acid compounds were identified by high-performance liquid chromatography-ultraviolet. The results show a significant difference between the several varieties under study in terms of their physico-chemical and phyto-chemical characteristics. In general, the studied apples are juiciness, with a percentage ranging from 60 to 71%. The pH values demonstrate how acidic the apples are. The Brix parameter denotes values greater than 13°Brix. Total polyphenols and condensed tannins (1154.65 ± 13.54 µg EAG/g and 514.09 ± 32.40 µg EAT/g, respectively) are more present in the Ahjjani variety than they are in other varieties. This demonstrates their good nutritional quality while not being consumable. However, the Story variety has a predominance of flavonoids (75.074 ± 2.309 µg QE/g) and flavones (45.074 ± 2.09 µg QE/g). The detection of organic acids has shown that the acid succinic is the most abundant in all the varieties of studied apple fruits. These results allow us to infer that non-consumable varieties are also important dietary sources of bioactive molecules, notably for polyphenols. The fact that these kinds can be used to produce other byproducts is therefore highly intriguing.

In situ growth of ZIF-67 to construct core-shell mosaic structural composites for efficient extraction of benzoylurea insecticides.

A novel mosaic structure Silica@C/Co@ZIF-67 composite was synthesized by successfully embedding Co nanoparticles on the surface of silica spheres with the help of thermoplastic polyethyleneimine by carbon-reduction. The ZIF-67 half-shell layer structure was synthesized by the in-situ growth of ZIF-67 on the surface of silica spheres through the coordination of 2-methylimidazole with Co metal nodes. The composite was used as a magnetic solid-phase extraction adsorbent combined with high performance liquid chromatography-ultraviolet detector (HPLC-UV) for the extraction and determination of benzoylurea insecticides (BUs) in vegetables and tea. Based on the presence of π-π, hydrophobic and hydrogen bonding interactions between Silica@C/Co@ZIF-67 and BUs, the BUs were rapidly captured by the composites resulting in high adsorption performance. Under the optimal extraction parameters, the linear ranges were 0.3-200µg L-1 for diflubenzuron, 0.6-200µg L-1 for chlorbenzuron, and 1.0-200µg L-1 for triflumuron, teflubenzuron, and flufenoxuron, with correlation coefficients (R2) greater than 0.9991. The limits of detection (LODs) of the method were 0.1-0.3μg L-1, and the relative standard deviations (RSDs) were 1.2-3.0% for intra-day and 2.6-4.6% for inter-day. In the spiked recovery experiments of vegetables and tea, the recoveries of the five kinds of BUs ranged from 75.8 to 112.9%. In addition, after 10 repetitions using Silica@C/Co@ZIF-67, the recoveries of the five kinds of BUs were still as high as 78.4 to 83.9%.

Magnetic r‐graphene oxide‐doped tin‐lanthanum intercalated thiosulfate layered double hydroxide as a new nanocomposite sorbent for the extraction of tetracycline and oxytetracycline residues in pharmaceutical wastewater

AbstractA new analytical method combining magnetic micro‐solid phase extraction (μ‐SPE) in tandem with high‐performance liquid chromatography‐ultraviolet (HPLC‐UV) analysis was developed and used for the simultaneous extraction/preconcentration of tetracycline (TC) and oxytetracycline (OTC) residues in drug manufacturing effluents. The μ‐SPE conducted by the introduction of iron oxide reduced‐graphene oxide (MrGO) doped tin‐lanthanium intercalated with thiosulfate ions to produce magnetic LDH (MrGO/Sn‐La‐S). The adsorbent was synthesized and characterized using x‐ray diffraction, Fourier transform infrared, scanning electron microscopy, energy‐dispersive x‐ray, elemental mapping, transmission electron microscopy, x‐ray photoelectron spectroscopy, and value stream mapping techniques. The effective parameters, including the extraction and desorption steps, were investigated and optimized. Under optimized conditions, the limits of detection (LOD) for TC and OTC were obtained as 5.42 and 3.31 μg.L−1, respectively, while the linearity was in the range of 10.0–500.0 μg.L−1 for both antibiotics with satisfactory determination coefficients (R2) of 0.9811 and 0.9846 for TC and OTC, respectively. The recovery percentages for the analytes in real samples were achieved in the ranges of 89.2%–101.6% and 91.0%–101.3% for TC and OTC antibiotics, respectively. All these features proved the potential of the developed method and adsorbent for real world applications.

Optimization and validation of high-performance liquid chromatography using modified QuEChERS to determine anthelmintic drugs in mutton.

The aim of this study was to rapidly determine the presence of anthelmintic drugs in sheep meat using the optimized high-performance liquid chromatography-ultraviolet (HPLC-UV) method with modified QuEChERS (quick, easy, cheap, effective, rugged, safe) technology. Fifty fresh sheep meat samples from different slaughterhouses were collected. A double extraction procedure (QuEChERS/HPLC-UV technology) was used to extract the target analytes. A multilevel calibration curve from 1 to 1000 g/kg was used to establish instrument linearity for rafoxanide, albendazole, and closantel, whereas 0.1-100 μg/kg was used for ivermectin, levamisole, and oxyclozanide to find the lowest concentration, maximum residue limit (MRL), and occupied range for targeted analytes. The concentration levels were used to investigate the linearity, whereas several certified reference materials were applied to determine accuracy. The process was linear for all combinations, from the limit of quantification (LOQ) to the maximum concentration. The LOQ was established at 0.5μg/kg for ivermectin, levamisole, and oxyclozanide and 10μg/kg for rafoxanide, albendazole, and closantel. Recovery values were 70%-120%, and repeatability/reproducibility stated in relative standard deviation was obtained at less than 20%. QuEChERS method revealed that most meat samples contained anthelmintic drug residues, of which the majority exceeded the MRLs. Thus, the drugs should be used correctly in animals to avoid residues in food for human consumption.

Identification of ascorbic acid  and phytochemical profiles of Scotch Bonnet pepper (Capsicum chinense) using High-Performance Liquid Chromatography-Ultraviolet  Detector (HPLC-UV)

Researchers have discovered that red and green scotch peppers are extremely rich in phytochemicals and that these secondary metabolites are connected to several biological processes in the human body. This study aimed to determine the numerous phytochemicals present in scotch pepper seeds, flesh, and red and green varieties. The samples were pulverized after being air-dried. The phytochemicals and ascorbic acid contents were examined using a High-performance Liquid Chromatography-Ultraviolet  detector (HPLC-UV). Twelve phytochemicals and ascorbic acid were identified in the flesh and seed of red scotch pepper, with lycopene having the highest content (83.10 mg/kg), the ascorbic acid content of 8.80 mg/kg; moreover, the seed of red scotch pepper revealed twelve phytochemicals and lycopene being the highest content (75.60 mg/kg) and ascorbic acid content of 6.80 mg/kg, furthermore, fourteen phytochemicals were identified in the flesh of red scotch bonnet pepper with lycopene the highest quantity (86.00 mg/kg) and ascorbic content of 10.60 mg/kg. Twelve phytochemicals were identified in the flesh and seed of green scotch bonnet pepper, lycopene (68.70 mg/kg) being the highest content, ascorbic acid content (6.50 mg/kg), twelve phytochemicals were revealed in the flesh of green pepper and lycopene had highest quantity (76.30 mg/kg), in the seed of green pepper, the lycopene content was 68.70 mg/kg. However, it has been shown that capsaicin, dihydrocapsaicin, and lutein concentrations varied, with red scotch pepper flesh having the highest concentration of capsaicin (7.50 mg/kg). The lycopene and ascorbic acid contents of flesh were the highest (86.00 mg/kg) and (10.60 mg/kg). The study's findings showed that red pepper flesh was better than other components that were looked at.  

Comparative Pharmacokinetic Study of Rhubarb Anthraquinones in Normal and Nonalcoholic Fatty Liver Disease Rats.

Rhubarb anthraquinones contain five main components, that is, rhein, emodin, aloe-emodin, chrysophanol, and physcion, which demonstrate good therapeutic effects on nonalcoholic fatty liver disease (NAFLD). However, research on its pharmacokinetics in NAFLD remains lacking. This study aimed to investigate the pharmacokinetic differences of rhubarb anthraquinones in normal and NAFLD rats. This study developed an NAFLD rat model by high-fat diet feeding for 6weeks. Normal and NAFLD groups were orally administered different rhubarb anthraquinones doses (37.5, 75, and 150mg/kg). The concentration of the rhein, emodin, aloe-emodin, chrysophanol, and physcion in plasma was determined by high-performance liquid chromatography-ultraviolet. The results revealed significant differences in pharmacokinetic behavior between normal and NAFLD rats. Compared with normal rats, NAFLD rats demonstrated significantly increased maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC0 → ∞) of rhubarb anthraquinones (P<0.05), as well as significantly prolonged time to reach maximum plasma concentration (Tmax), terminal elimination half-life (t1/2), and mean residence time (MRT) of rhubarb anthraquinones (P<0.05). This study indicates significant differences in the pharmacokinetics of rhubarb anthraquinones between the physiological and NAFLD states of rats. Rhubarb anthraquinone demonstrated a longer retention time and slower absorption rate in NAFLD rats and exhibited higher bioavailability and peak concentration. This finding provides important information for guiding the clinical use of rhubarb anthraquinones under pathological conditions.

Preparation and extraction property study of corn cob-like magnetic mosaic carbon materials derived from MOF-on-MOF composites

BackgroundLarge accumulations of pesticide residues in the environment eventually enter the human body with food. Based on magnetic solid-phase extraction (MSPE) technology, it is possible to achieve efficient extraction of trace pesticide residues in foodstuffs, and the construction of MSPE adsorbents with excellent magnetic properties and many active sites is still one of the main research topics. Based on this, we developed a new strategy for the preparation of "MOF-on-MOF" composites, which were carbonized and used as adsorbents for the extraction of pesticide residues in cereals. ResultsA novel corn cob core-shell composite Fe2O3@C@ZIF-8 was created by embedding ZIF-8 onto the surface of Fe2O3@C derived from MIL-88A(Fe), and used for the extraction of benzoylurea insecticides(BUs) from cereals. The adsorption behaviour between Fe2O3@C@ZIF-8 and BUs was investigated by static and kinetic experiments and the adsorption mechanism was elaborated. For the trace analysis of BUs, a magnetic solid-phase extraction combined with high performance liquid chromatography-ultraviolet detector (HPLC-UV) approach was also developed. Under the optimized experimental conditions, the limits of detection and quantification were 0.015–0.03 μg L−1 and 0.05–0.1 μg L−1, and the relative standard deviations for the intra-day and inter-day ranges were 1.82%–2.13 % and 3.85%–4.59 %, respectively. The spiked recoveries of the four cereals ranged from 82.72% to 104.45 %. After 10 cycles of use of Fe2O3@C@ZIF-8, the recoveries of BUs ranged from 77.90% to 96.74 %. SignificanceThe analytical method based on Fe2O3@C@ZIF-8 as adsorbent has a low limit of detection, a wide linear range and is highly applicable to the analysis of real samples. In addition, the strategy developed in this study for the preparation of thermoplastic polymer-assisted "MOF-on-MOF" composites has promising applications.

Pharmacokinetics of meloxicam following intravenous administration at different doses in sheep.

The aim of this study is to determine the pharmacokinetic change after intravenous administration of meloxicam at doses of 0.5, 1 and 2 mg/kg to sheep. The study was carried out on six Akkaraman sheep. Meloxicam was administered intravenously to each sheep at 0.5, 1, and 2 mg/kg doses in a longitudinal pharmacokinetic design with a 15-day washout period. Plasma concentrations of meloxicam were determined using the high performance liquid chromatography-ultraviolet, and pharmacokinetic parameters were evaluated by non-compartmental analysis. Meloxicam was detected up to 48 h in the 0.5 mg/kg dose and up to 96 h in the 1 and 2 mg/kg doses. As the dose increased from 0.5 to 2 mg/kg, terminal elimination half-life, and dose normalized area under the concentration versus time curve increased and total clearance decreased. Compared to the 1 mg/kg dose, it was determined that Vdss decreased and C0.083h increased in the 2 mg/kg dose. Meloxicam provided the therapeutic concentration of >0.39 μg/mL reported in other species for 12, 48 and 96 h at 0.5, 1 and 2 mg/kg doses, respectively. These results show that meloxicam exhibits non-linear pharmacokinetics and will achieve unpredictable plasma concentrations when administered IV for a rapid effect at dose of ≥1 mg/kg in sheep.

Eco-friendly micellar HPLC approach for simultaneous estimation of combination therapy for hidradenitis suppurativa: Applications to spiked human plasma and different dosage forms.

This study introduces a new method for analyzing rifampicin, moxifloxacin, and metronidazole using a green micellar High Performance Liquid Chromatography-Ultraviolet method in bulk drugs, different commercial formulations, and spiked human plasma. The combined therapy of these three broad-spectrum antibiotics is used to cure refractory hidradenitis suppurativa (HS), an inflammatory condition affecting the skin. The sustainable separation was attained on a reversed-phase C18 Kinetex® column maintained at ambient temperature in less than 5 min. The mobile phase comprises 0.1 M sodium dodecyl sulfate (SDS) in water, pH 3.5, adjusted using o-phosphoric acid, and 10% n-butanol. The flow rate was 1 mL/min, with 10 μL injection volume and UV detection at 230 nm. The impact of three key significant variables, SDS concentration, n-butanol percentage, and the mobile phase pH, on suitability parameters was studied. ICH and FDA guidelines were committed to when validating the technique. The results showed linear calibration graphs with high precision and accuracy, in both pure and spiked plasma. The method is efficient, easy to use, and has a high sample throughput, making it suitable for routine analysis in the quality control department and therapeutic monitoring. It is also evaluated as a green-and-white substitute for traditional reported methods.

A Simple HPLC-UV Method for Ivosidenib Determination in Human Plasma.

Ivosidenib is used for the treatment of acute myeloid leukemia (AML) with isocitrate dehydrogenase 1 (IDH1) mutations. However, increased blood concentrations of ivosidenib are associated with a risk of a prolonged QT interval in patients with AML. Therapeutic drug monitoring in patients with AML with IDH1 mutation offers the potential to improve treatment efficacy while minimizing toxicity. In this study, we developed an efficient high-performance liquid chromatography-ultraviolet (HPLC-UV) method for the quantification of ivosidenib in plasma. Human plasma samples (50μL) were processed by protein precipitation using acetonitrile, followed by chromatographic separation on a reversed-phase column with an isocratic mobile phase of 0.5% KH₂PO₄ (pH4.5) and acetonitrile (45:55, v/v) at a flow rate of 1.0mL/min, with ultraviolet detection at 245nm. Calibration curves were linear over the range of 0.25-20μg/mL with a coefficient of determination (r2) of 0.99999. Intra-day and inter-day precision were 1.20-8.04% and 0.69-4.20%, respectively. The assay accuracy was -2.00% to 1.93% and recovery was >91.2%. These findings support the effectiveness of the newly developed HPLC-UV method for the quantification of ivosidenib in human plasma. This simple and cost-effective method is expected to expand ivosidenib monitoring in laboratories lacking LC-MS/MS instruments.

Validation of a method for measuring rifampicin plasma drug concentration in tuberculosis patients

Rifampicin is a first-line drug used in the management of tuberculosis (TB) due to its sterilizing effect that targets the bacteria responsible for the disease. This study modified and validated a method for quantitatively determining rifampicin plasma drug concentration of TB patients through High Performance Liquid Chromatography Ultraviolet Visible detection. The analytic method modified from a standard method was validated for linearity, coefficient of variation, intra-day and inter-day precision, and recovery rate. The retention time of rifampicin was reduced from 18.3 to 3.1 minutes after the method was modified. To validate the method, the coefficient of determination was determined for the linearity to be between 0.975 and 0.998, the coefficient of variation ranged between 2.8% to 15.5% for both intra-day and inter-day precision. Recovery rates ranged between 87% and 125%. The results indicated that the analytical method developed was valid, precise and feasible, and could be useful for quantitatively determining rifampicin plasma drug concentration in TB patients.