Salting-out induced liquid-liquid microextraction for alogliptin benzoate determination in human plasma by HPLC/UV

Current green capillary electrophoresis and liquid chromatography methods for analysis of pharmaceutical and biomedical samples (2019-2023) - A review

Separation analytical methods, including liquid chromatography (LC) and capillary electrophoresis (CE), in combination with an appropriate detection technique, are dominant and powerful approaches preferred in the analysis of pharmaceutical and biomedical samples. Recent trends in analytical methods are focused on activities that push them to the field of greenness and sustainability. New approaches based on the implementation of greener solvents, non-hazardous chemicals, and reagents have grown exponentially. Similarly, recent trends are pushed in to the strategies based on miniaturization, reduction of wastes, avoiding derivatization procedures, or reduction of energy consumption. However, the real greenness of the analytical method can be evaluated only according to an objective and sufficient metric offering complex results taking into account all twelve rules of green analytical chemistry (SIGNIFICANCE mnemonic system). This review provides an extensive overview of papers published in the area of development of green LC and CE methods in the field of pharmaceutical and biomedical analysis over the last 5 years (2019-2023). The main focus is situated on the metrics used for greenness evaluation of the methods applied for the determination of bioactive agents. It critically evaluates and compares the demands of the real applicability of the methods in quality control and clinical environment with the requirements of the green analytical chemistry (GAC). Greenness and practicality of the summarized methods are re-evaluated or newly evaluated with the use of the dominant metrics tools, i.e., Analytical GREEnness (AGREE), Green Analytical Procedure Index (GAPI), Blue Applicability Grade Index (BAGI), and Sample Preparation Metric of Sustainability (SPMS). Moreover, general conclusions and future perspectives of the greening procedures and greenness evaluation metrics systems are presented. This paper should provide comprehensive information to analytical chemists, biochemists, and it can also represent a valuable source of information for clinicians, biomedical or quality control laboratories interested in development of analytical methods based on greenness, practicality, and sustainability.

Applications of metal organic frameworks in dispersive micro solid phase extraction (D-μ-SPE)

Metal-organic frameworks (MOFs) are a fascinating family of crystalline porous materials made up of metal clusters and organic linkers. In comparison with other porous materials, MOFs have unique characteristics including high surface area, homogeneous open cavities, and permanent high porosity with variable shapes and sizes. For these reasons, MOFs have recently been explored as sorbents in sample preparation by solid-phase extraction (SPE). However, SPE requires large amounts of sorbents and suffers from limited contact surfaces with analytes, which compromises extraction recovery and efficiency. Dispersive SPE (D-SPE) overcomes these limitations by dispersing the sorbents into the sample, which in turn increases contact with the analytes. Miniaturization of the microextraction procedure, particularly the amount of sorbent reduces the amount consumed of the organic solvent and shorten the time required to attain the equilibrium state. This may explain the reported high efficiency and applicability of MOFs in dispersive micro SPE (D-µ-SPE). This method retains all the advantages of solid phase extraction while also being simpler, faster, cheaper, and, in some cases, more effective in comparison with D-SPE. Besides, D-µ-SPE requires smaller amounts of the sorbents which reduces the overall cost, and the amount of waste generated from the analytical process. In this review, we discuss the applications of MOFs in D-µ-SPE of various analytes including pharmaceuticals, pesticides, organic dyes from miscellaneous matrices including water samples, biological samples and food samples.

Ternary solvent based homogeneous liquid-liquid microextraction for the preconcentration of organochlorine pesticides from water and apple juice samples

In the present study, the optimal experimental conditions were determined by optimizing the effect of extraction solvent types and volume, salt types and concentration, centrifugation speed and time using one variable at a time. Under optimal experimental conditions, calibration curves were constructed separately using water and apple juice samples as representative matrices, and good linearities were achieved over a wide concentration range of 0.2-1600 ng L-1 with a coefficient of determination (r2) ≥ 0.998. The limits of detection (LOD) and limits of quantification (LOQ), determined to be 3 and 10 times the signal-to-noise ratios (S/N), were between 0.07-3.9 and 0.2-12.0 ng L-1 for water samples and 2.6-10.0 and 8.0-30.0 ng L-1 for the apple juice sample respectively. The precisions study showed %RSD values of ≤6% for both matrices, indicating satisfactory precisions. The enrichment factors and recoveries of the proposed method ranged from 41.4-74.5 and 86-109% respectively. The proposed method could be used as a simple and environmentally friendly alternative for the analysis of OCPs from environmental and food matrices. This method potentially offers a more sustainable and effective approach to monitoring OCPs in environmental and food products. Its use in the analysis of apple juice samples is particularly novel and can provide valuable insights into pesticide contamination in fruit juices.

Homogeneous liquid-liquid microextraction coupled with HPLC/DAD for determination of nirmatrelvir and ritonavir as COVID-19 combination therapy in human plasma

The study reports the development of a high-performance liquid chromatography/diode array detection method to measure the levels of nirmatrelvir and ritonavir in human plasma. These two antiviral medications are used for the treatment of COVID-19 and are marketed as Paxlovid®. The method employed sugaring-out induced homogeneous liquid-liquid microextraction to improve sensitivity. Optimization of the method was performed using the one variable at a time approach by adjusting several factors such as type of sugar, extractant, amount of sugar, volume of extractant, and pH of the aqueous sample to achieve the highest efficiency. The developed method was validated according to the Food and Drug Administration guidelines and demonstrated good linearity, accuracy, and precision. The range of linearity was from 1000 to 20,000 ng/mL for nirmatrelvir and 200 to 20,000 ng/mL for ritonavir with correlation coefficient values of 0.998 and 0.996, respectively. Selectivity studies revealed that no others peaks appeared in the retention times of the studied drugs. The stability of nirmatrelvir and ritonavir were also investigated through short term and three cycles of freeze-thaw, and both drugs were found stable. This analytical method could be useful for monitoring drug concentrations in patients undergoing treatment with these medications for COVID-19. In this work, for the first time, SULLME was used for the sensitive determination of nirmatrelvir and ritonavir in biological fluids. The developed method was able to determine both drugs in therapeutic levels with no need to sophisticated techniques like LC-MS. In addition to that, SULLME is considered a simple and green sample preparation in comparison with conventional sample preparation methods.

Analytical Methods for the Determination of Quercetin and Quercetin Glycosides in Pharmaceuticals and Biological Samples

Flavonoids are plant-derived compounds that have several health benefits, including antioxidative, anti-inflammatory, anti-mutagenic, and anti-carcinogenic effects. Quercetin is a flavonoid that is widely present in various fruits, vegetables, and drinks. Accurate determination of quercetin in different samples is of great importance for its potential health benefits. This review, is an overview of sample preparation and determination methods for quercetin in diverse matrices. Previous research on sample preparation and determination methods for quercetin are summarized, highlighting the advantages and disadvantages of each method and providing insights into recent developments in quercetin sample treatment. Various analytical techniques are discussed including spectroscopic, chromatographic, electrophoretic, and electrochemical methods for the determination of quercetin and its derivatives in different samples. UV-Vis (Ultraviolet-visible) spectrophotometry is simple and inexpensive but lacks selectivity. Chromatographic techniques (HPLC, GC) offer selectivity and sensitivity, while electrophoretic and electrochemical methods provide high resolution and low detection limits, respectively. The aim of this review is to comprehensively explore the determination methods for quercetin and quercetin glycosides in diverse matrices, with emphasis on pharmaceutical and biological samples. The review also provides a theoretical basis for method development and application for the analysis of quercetin and quercetin glycosides in real samples.

A hybrid microcrystalline cellulose/metal-organic framework for dispersive solid phase microextraction of selected pharmaceuticals: A proof-of-concept

Solid phase microextraction (SPME) is considered simple, ecofriendly, sustainable, cost-effective and timesaving sample preparation mode in comparison with other sample preparation procedures. The researchers always try to develop new sorbents with higher surface area in comparison with other conventional sorbents aiming to enhance the extraction efficiency. In this work for the first time, a comparative study was performed between Ca-BTC MOF (1,3,5-benzenetricarboxylic acid, BTC; metal-organic framework, MOF) and a hybrid Ca-BTC-MCC MOF (microcrystalline cellulose, MCC) by using as model compounds seven drugs with different physicochemical properties. The evaluation of the extraction efficiency of both sorbents were obtained by means of an HPLC/DAD instrument configuration in reversed phase mode under isocratic elution mode. The results indicate that Ca-BTC MOF showed superior extraction efficiency than Ca-BTC-MCC MOF in the case of all analytes except nirmatrelvir and ritonavir. The results highlight that not only the surface area of adsorbents controlled the adsorption capacity, but also other factors have a role in extraction efficiency including morphology of adsorbent and physico-chemical properties of the analytes. It is worth mentioning that this is the first time that a comparative study was performed between Ca-BTC MOF and Ca-BTC-MCC MOF hybrid material.

An Effective Chromatographic Method for Simultaneous Quantification of Antidiabetic Drugs Alogliptin Benzoate and Pioglitazone HCl in Their Tablet Dosage Form: Implementation to In vitro Dissolution Studies and Uniformity of Dosage Unit

In patients with Type 2 diabetes, a combination of Alogliptin and Pioglitazone medications, together with diet and physical activity, are used to improve glycemic control. Eco-friendly, cost-effective, and precise stability-indicating RP-HPLC method was developed and validated for the identification and quantification of Alogliptin and Pioglitazone in their tablet dosage form, as well as implementation to in vitro dissolution studies and uniformity of dosage unit. Isocratic separation is conducted at ambient temperature on the InertSustain C18 Analytical Column (150 × 4.6 mm, 5 μm) using mobile phase comprising 50 mM of ammonium dihydrogen phosphate and 5.0 mM of heptane sulfonic acid:acetonitrile (45:55, v/v) at a flow rate of 1.3 mL/minute. Calibration curves are conducted in the linearity range of 1-40 μg/mL of Alogliptin and 2.5-75 μg/mL of Pioglitazone with a correlation value >0.9995 and satisfactory recovery findings between 99 and 100%. The degraded samples are analyzed under relevant stress conditions as acidity, alkalinity, thermal and oxidation. The active components in finished products were subjected to a content uniformity test, which showed that they achieved the declared claim's acceptance standards (85-115%). Comparative in vitro dissolution studies are performed for generic products Inhibazone 12.5/30 mg FCT and Inhibazone 25/15 mg FCT against innovator products Oseni 12.5/30 mg FCT and Oseni 25/15 mg FCT at suitable FDA dissolution medium and different USP dissolution media and the results are similar. The metrics of the designed method were assessed according to ICH requirements, and all metrics, such as system suitability, linearity, recovery, robustness, LOD, LOQ, specificity and precision, were found to be within required tolerances and no overlapping was found for degradation peaks. Thence, the method can be used in quality control for the analysis of raw material, bulk, finish and stability.

A Highly Selective Analytical Method Based on Salt-Assisted Liquid-Liquid Extraction for Trace-Level Enrichment of Multiclass Pesticide Residues in Cow Milk for Quantitative Liquid Chromatographic Analysis

In this study, a simple, inexpensive, selective, and fast salting-out assisted liquid-liquid extraction (SALLE) technique coupled with high-pressure liquid chromatography-diode array detection (HPLC-DAD) was developed for the extraction, preconcentration, and analysis of trace level seven multiclass pesticide residues in pasteurized and raw cow milk samples. The significant factors that affect the extent to which the target analytes are extracted, such as the type of extraction solvent and its volume, the type and concentration of salting-out salts, the pH of the solution, and the extraction time, have been investigated. Under optimum conditions, the correlation coefficient (r2) was obtained within a range of 0.9982-0.9997 for a broad linear range concentration of 2-1500 ng·mL-1. Reliable sensitivity was achieved with limits of detection (LODs) and limits of quantification (LOQs) ranging from 0.58-2.56 ng·mL-1 and 1.95-8.51 ng·mL-1, respectively. While precision with interday and intraday in terms of relative standard deviations (RSDs) was observed in the range of 1.97 - 7.88% and 4.52 - 8.04%, respectively. The results of the precision studies reveal that good repeatability and reproducibility (RSDs <9) were achieved, thus showing a low variability extraction of the developed method. Finally, the proposed and validated approach was effectively used to extract and determine pesticide residues in real milk matrices; however, the target analytes were not detected in all samples.

New Class of Tunable Choline Bromide-Based Hydrophobic Deep Eutectic Solvents for the Extraction of Bioactive Compounds of Varying Polarity from a Plant Matrix

Deep eutectic solvents (DESs) are a class of sustainable solvents that have found numerous applications in different fields. One of their main attributes is the possibility of easily modifying their physicochemical properties by varying the type of hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) that comprise them. Choline chloride ([Ch⁺][Cl^-])-based hydrophilic DESs were among the first studied and the most used because of their capacity to easily create a hydrogen bonding network that lies in its unique chemical structure, characterized by a hydroxyl substituent within the ammonium headgroup. In this study, a new class of hydrophobic [Ch⁺][Br^-]-modified salts were synthesized to produce HBAs with similar properties to choline for the preparation of hydrophobic DESs. Six different [Ch⁺][Br^-]-based HDESs were prepared and characterized in terms of hydrophobicity, viscosity, and solvation properties (hydrogen bonding, dispersion, dipolarity/polarizability, n-π, and π-π interactions). They were employed as solvents in a microextraction method for the determination of phytochemicals in Cannabis sativa L. plant. The extraction performance of the [Ch⁺][Br^-]-based HDESs was compared to eutectic mixtures based on conventional hydrophobic HBAs, and the results revealed that the unique properties of [Ch⁺][Br^-]-modified salts allowed for the extraction of both hydrophilic (i.e., flavonoids) and hydrophobic compounds (i.e., cannabinoids).

Construction and application of highly sensitive spinel nanocrystalline zinc chromite decorated multiwalled carbon nanotube modified carbon paste electrode (ZnCr2O4@MWCNTs/CPE) for electrochemical determination of alogliptin benzoate in bulk and its dosage form: green chemistry assessment

A new sensor for alogliptin benzoate (ALG) estimation based on a simple and sensitive method was evolved on multiwalled-carbon-nanotube modified nanocrystalline zinc chromite carbon paste electrodes (ZnCr₂O₄@MWCNTs/CPEs). ALG electrochemical behavior was evaluated using a cyclic voltammetry (CV), square wave voltammetry (SWV) and chronoamperometry (CA). The new electrode materials were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray analysis (EDX) for elemental analysis and mapping, and X-ray diffraction (XRD) and the X-ray photoelectron spectroscopy (XPS) measurements. All these measurements exhibiting enhanced activity and high conductivity compared to the bare electrode without modification. The calibration curves obtained for ALG were in the ranges of 0.1–20 μmol L⁻¹ with a quantification and detection limits of 0.09 and 0.03 μmol L⁻¹, respectively. The prepared sensor showed a good sensitivity and selectivity with less over potential for ALG determination. Finally, the presented method was successfully applied as a simple, precise and selective electrochemical electrode for the estimation of ALG in its pharmaceutical dosage form.

A new sensor for alogliptin benzoate (ALG) estimation based on a simple and sensitive method was evolved on multiwalled-carbon-nanotube modified nanocrystalline zinc chromite carbon paste electrodes (ZnCr₂O₄@MWCNTs/CPEs).

Menthol-assisted homogenous liquid-liquid microextraction for HPLC/UV determination of favipiravir as an antiviral for COVID-19 in human plasma

Favipiravir is a promising antiviral agent that has been recently approved for treatment of COVID-19 infection. In this study, a menthol-assisted homogenous liquid–liquid microextraction method has been developed for favipiravir determination in human plasma using HPLC/UV. The different factors that could affect the extraction efficiency were studied, including extractant type, extractant volume, menthol amount and vortex time. The optimum extraction efficiency was achieved using 300 µL of tetrahydrofuran, 30 mg of menthol and vortexing for 1 min before centrifuging the sample for 5 min at 3467g. Addition of menthol does not only induce phase separation, but also helps to form reverse micelles to facilitate extraction. The highly polar favipiravir molecules would be incorporated into the hydrophilic core of the formed reverse micelle to be extracted by the non-polar organic extractant. The method was validated according to the FDA bioanalytical method guidelines. The developed method was found linear in the concentration range of 0.1 to 100 µg/mL with a coefficient of determination of 0.9992. The method accuracy and precision were studied by calculating the recovery (%) and the relative standard deviation (%), respectively. The recovery (%) was in the range of 97.1–103.9%, while the RSD (%) values ranged between 2.03 and 8.15 %. The developed method was successfully applied in a bioequivalence study of Flupirava® 200 mg versus Avigan® 200 mg, after a single oral dose of favipiravir administered to healthy adult volunteers. The proposed method was simple, cheap, more eco-friendly and sufficiently sensitive for biomedical application.

Hantzsch Condensation Reaction as a Spectrofluorometric Method for Determination of Alogliptin, an Anti-diabetic Drug, in Pure, Tablet, Human, and rat plasma

To analyze alogliptin in its pharmaceutical dosage forms and human plasma, a sensitive, inexpensive, simple, and precise spectrofluorimetric method was developed and tested. Also, this method was used to investigate the drug pharmacokinetic behavior in the blood of rats. It is based on the Hantzsch reaction, which produces yellowish luminous products that can be detected spectrofluorometrically at 480 and 415 nm, emission, and excitation, respectively, when the primary amine group in the examined drug reacts with acetylacetone and formaldehyde. Several experimental parameters that affect the reaction product's development and stability were explored and improved. The curve of fluorescence and concentration for alogliptin was linear in the concentration range of 0.05-3.60 μg ml^-1 . According to ICH criteria, the proposed approach was validated. The method was successfully utilized to evaluate the examined drug in dose formulations and spiked human plasma with high accuracy.

Homogeneous liquid-liquid extraction as an alternative sample preparation technique for biomedical analysis

Liquid-liquid extraction is a widely used technique of sample preparation in biomedical analysis. In spite of the high pre-concentration capacities of liquid-liquid extraction, it suffers from a number of limitations including time and effort consumption, large organic solvent utilization, and poor performance in highly polar analytes. Homogeneous liquid-liquid extraction is an alternative sample preparation technique that overcomes some drawbacks of conventional liquid-liquid extraction, and allows employing greener organic solvents in sample treatment. In homogeneous liquid-liquid extraction, a homogeneous phase is formed between the aqueous sample and the water-miscible extractant, followed by chemically or physically induced phase separation. To form the homogeneous phase, aqueous samples are mixed with water-miscible organic solvents, water-immiscible solvents/cosolvents, surfactants, or smart polymers. Then, phase separation is induced chemically (adding salt, sugar, or buffer) or physically (changing temperature or pH). This mode is rapid, sustainable, and cost-effective in comparison with other sample preparation techniques. Moreover, homogeneous liquid-liquid extraction is more suitable for the extraction of delicate macromolecules such as enzymes, hormones, and proteins and it is more compatible with liquid chromatography with tandem mass spectrometry, which is a vital technique in metabolomics and proteomics. In this review, the principle, types, applications, automation, and technical aspects of homogeneous liquid-liquid extraction are discussed.

Sugaring-out induced homogeneous liquid-liquid microextraction as an alternative mode for biological sample preparation: A comparative study

Miniaturization of liquid-liquid extraction is a growing field of sample preparation to reduce solvent consumption, protect the environment, and preserve operators' health. In this work, four different modes of liquid-liquid microextraction have been compared including dispersive liquid-liquid microextraction, binary and ternary salting-out, and sugaring-out induced liquid-liquid microextraction. The extraction efficiency was evaluated by the enrichment factors of 14 different drugs from three pharmacological classes. Compared with the other modes, sugaring-out induced liquid-liquid microextraction was found to be the most efficient and, thus, it was applied for sample preparation of the antivirals in human plasma. Method optimization was performed using response surface methodology for the sugar type and amount (in mg), the sample pH, the equilibration time (in min), and the extractant volume (in µL). The method was then validated and found linear in the concentration range of 0.10-10 µg/mL for daclatasvir, 0.05-10 µg/mL for velpatasvir, and 0.20-10 µg/mL for ledipasvir, with correlation coefficients in the range 0.996-0.999. These results shows that sugaring-out induced liquid-liquid microextraction could be a more efficient microextraction mode for preparation of biological samples. Compared with other types of microextraction, sugaring-out induced liquid-liquid microextraction is greener, simpler, and cost-effective, with less tendency to affect the sample pH.