Analytical Eco-Scale Research Articles

Quality-by-design optimized RP-HPLC approach for the therapeutic drug monitoring of glibenclamide and fluoxetine in human plasma

Glibenclamide (GLB) and fluoxetine (FLX) were reported to have a potential drug-drug interaction when clinically co-administered. FLX is an inhibitor of CYP2C9 (the enzyme responsible for the metabolism of GLB), thus resulting in increased serum levels of GLB followed by severe hypoglycemia. Therefore, a sensitive, simple, and selective HPLC method is urgently needed for their simultaneous determination in plasma to be utilized for monitoring their therapeutic blood concentration levels. The current study introduces the first RP-HPLC approach for the simultaneous estimation of this binary mixture in less than 7 min. Adopting a quality-by-design (QbD) approach allowed for the designed approach to be optimized. Using a two-level full factorial design (25), the effects of various variables on the chromatographic responses were investigated and optimized. Hypersil BDS C18 column was used for the achievement of the optimum chromatographic separation at 19.9 °C using acetonitrile: sodium dihydrogen phosphate buffer (7.5 mM; pH 4, 60:40 % v/v) as a mobile phase, pumped isocratically at a flow rate of 1.036 mL/min. An injection volume of 30.0 μL was used for the binary mixture with UV detection at 230 nm. FLX and GLB calibration curves revealed an excellent linearity over the ranges of 0.025–10.00 and 0.02–10.00 µg/mL with limits of quantitation of 0.018 and 0.02 µg/mL, respectively. Due to the high sensitivity and selectivity, the method was successfully applied to the assay of the two drugs in spiked human plasma samples with reasonable % recoveries (92.70–108.50 %), indicating good bioanalytical applicability. Therefore, this study could be applied for the therapeutic drug monitoring of GLB and FLX in human plasma to control their potential drug-drug interaction. The suggested approach was also applied to estimate the investigated drugs in their dosage forms with reasonable % recoveries (96.80–102.80 %) and small % RSD values (less than 2 %). The method's excellent greenness was evaluated using three metric tools, including Analytical Eco-Scale, Green Analytical Procedure Index (GAPI), and Analytical Greenness (AGREE). Validation of the proposed method was performed according to ICH and US FDA guidelines.

The worthy green heterogeneous Fenton degradation process for removal of E102 in foodstuffs and industrial waste-waters using Cypress arizonica leaves based magnetic nanocomposite (CA-Fe3O4-MNc)

A new, green magnetic nanocomposite (MNc) was synthesized based on framework of Cypress arizonica (CA) leaves and then used as Fenton catalyst for removal of tartrazine (E102) in foodstuffs and industrial waste-waters. Characterization of the synthesized magnetic nanocomposite (CA-Fe3O4-MNc) was performed with IR, EDX, FESEM, XRD and pHpzc analyses. The average particle size and pHpzc of the CA-Fe3O4-MNc were determined to be 24.36 nm and 6.8, respectively. CA-Fe3O4-MNc was composed of C (15.08 %), Fe (51.86 %), O (31.80 %) and Ca (1.26 %) elements. The parameters effecting heterogeneous Fenton dye removal process including pH, catalyst amount, reaction time, H2O2 and initial dye concentrations were investigated to achieve the best removal efficiency for E102. Under optimal conditions, the matrix effect was investigated, the reusability of CA-Fe3O4-MNc was tested, degradation products and mechanism were elucidated, and green analytical procedure index (GAPI) and analytical eco-scale (AES) of the proposed Fenton degradation process were evaluated. E102 removal values were obtained between 93 and 99 % in the applications of some foodstuffs, water samples and artificial model dye solutions. Proposed heterogeneous Fenton removal process with using CA-Fe3O4-MNc catalyst exhibited quantitative removal efficiency for E102. E102 concentrations between 5 and 50 mg/L were removed successfully. It was observed that the synthesized CA-Fe3O4-MNc material could be used at least 5 times to obtain quantitative removal values. The percent removal efficiency value decreased to 93 after five uses. Defined GAPI parameters and calculated AES scores indicated that the proposed CA-Fe3O4-MNc based heterogeneous Fenton degradation process could be considered that a valuable green removal method.

EVALUATION OF GREENNESS PROFILES OF VARIOUS DEVELOPED METHODS FOR THE DETERMINATION OF COMMONLY USED NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDs) IN ENVIRONMENTAL WATERS

Objective: In our study, it was aimed to make a comparative analysis of the environmental impact profiles of two approaches including Gas Chromatography (GC) and Liquid Chromatography (LC) methods, which are frequently used techniques for the determination of non-steroidal anti-inflammatory drugs (NSAIDs) and their metabolites in environmental water samples. Material and Method: The evaluation of the methods' environmental impact was performed using National Environmental Methods Index Label (NEMI), Analytical Eco-scale, Analytical GREEnness Metric (AGREE), and Green Analytical Procedure Index (GAPI). Result and Discussion: The routine analysis of NSAIDs in environmental waters is carried out, resulting in a significant volume of chemical waste. In recent times, there has been a growing significance attributed to environmentally conscious analytical methodologies and the evaluation of methodologies through a green lens to confront this challenge. There is no statistically significant difference in terms of environmental impact profile was observed between the two methods compared.

Isoquinoline-based intrinsic fluorescence assessment of erythropoiesis-stimulating agent, Roxadustat (FG-4592), in tablets: applications to content uniformity and human plasma evaluation.

In the present study, a first validated and green spectrofluorimetric approach for its assessment and evaluation in different matrices was investigated. After using an excitation wavelength of 345 nm, Roxadustat (ROX) demonstrates a highly native fluorescence at an emission of 410 nm. The influences of experimental factors such as pH, diluting solvents, and different organized media were tested, and the most appropriate solvent choice was ethanol. It was confirmed that there was a linear relationship between the concentration of ROX and the relative fluorescence intensity in the range 60.0-1000.0 ng ml-1, with the limit of detection and limit of quantitation, respectively, being 17.0 and 53.0 ng ml-1. The mean recoveries % [±standard deviation (SD), n =5] for pharmaceutical preparations were 100.11% ± 2.24%, whereas for plasma samples, they were 100.08 ± 1.08% (±SD, n =5). The results obtained after the application of four greenness criteria, Analytical Eco-Scale metric, NEMI, GAPI, and AGREE metric, confirmed its eco-friendliness. In addition, the whiteness meter (RGB12) confirmed its level of sustainability. The International Council for Harmonisation (ICH) criteria were used to verify the developed method through the study in both spiked plasma samples and content uniformity evaluation. An appropriate standard for various applications in industry and quality control laboratories was developed.

Miniaturized on-spot protein denaturation/microwave-assisted extraction for spectrofluorimetric determination of favipiravir in dried plasma: Application to real human sample and inclusive incurred sample reanalysis study

The development of high-throughput sample preparation methods is a key step for upgrading the throughput of classical analytical techniques. In this work, a miniaturized on-spot protein denaturation coupled with microwave-assisted extraction sample treatment method was developed for extraction and subsequent spectrofluorimetric determination of favipiravir (FAV) in human plasma spots. Dried plasma spotting was performed using only 10 µL of plasma on filter paper discs followed by on-spot protein denaturation using 10 µL methanol. Maximum extraction efficiency was achieved using water: methanol (1:1) as extraction solvent with 50 % microwave power for 60 sec. The fluorescence intensity of extracted FAV was measured at 432 nm after excitation at 361 nm. According to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH -M10) guidelines for bioanalytical method validation, spiked plasma samples showed very good linearity between 100 and 1000 ng/mL. The accuracy and precision of the developed method were indicated by mean recovery (%) within 100 ± 15 % for all tested concentrations levels. The obtained results were further compared with a reported protein precipitation method using both F-test and t-test revealing no significant difference between either method. Moreover, the method was successfully applied for FAV determination in real human samples for an incurred sample reanalysis study revealing no metabolite back conversion. The developed method showed superior green performance using analytical Eco-scale, Green Analytical Procedure Index (GAPI), and Analytical Greenness Metric Approach (AGREE) tools compared to a classical protein precipitation method. According to Blue Applicability Grade Index (BAGI), and whiteness tools, the developed method outperformed all reported methods for FAV determination in plasma in terms of practicality and analytical functionality. Compared to reported sample treatment methods, this method exhibited excellent analytical performance, increased throughput, hundred-fold reduction of sample volume (10 μL), significant reduction of organic solvent consumption (260 μL methanol) and produced negligible wastes. Thus, it can be adopted for routine work in pharmacokinetics and clinical trial studies.

Green Analytical HPLC Method Development of Acyclovir Loaded Floating Raft Formulation in Spiked Rabbit Plasma

Objective: The need of this investigation is to design eco-friendly, sensitive, and precise bioanalytical high-performance liquid chromatography (HPLC) techniques that leverage green analytical tools such as green analytical procedure index (GAPI), analytical eco scale (AES), and analytical greenness metric (AGREE) to analyze ACV-spiked rabbit plasma and ACV-loaded floating raft formulation (FRF) because The literature survey revealed insufficient data for the HPLC approach to FRF. Method: Methods involving plasma spikes mirroring the in-vivo models provide insights into potential real-life scenarios and the functionality of floating raft formulations loaded with ACV. The Design Expert tool optimized critical process parameters and identified significant factors influencing the chromatographic technique. Results: The CCD was used to optimize the flow rate (0.6 mL/min) and buffer solvent ratio (99:1) for separation. The C18 column (250 X 4.6 mm) was utilized to achieve the elution of ACV. The developed method was thoroughly validated through ICH guidelines. The ACV, lower limit of detection (LLoD), and lower limit of quantitation (LLoQ) retention times were established at 2.3 minutes, 15, and 20 ng/mL, respectively. Discussion: In summary, the study demonstrated the exceptional performance sensitivity, specificity, and robustness of the bioanalytical method. The method proved highly effective in quantifying ACV in plasma samples in terms of revalidatability, transferability, reproducibility, and the product development cycle. The developed method proves that using both design of experiments (DoE) and green analytical chemistry together creates a valid, eco-friendly, and reliable way to analyze the making of an ACV-loaded floating raft formulation.

Incorporation of eggshell waste in the preparation of carbon quantum dot nanoprobes for the determination of COVID-19 antiviral drug; molnupiravir

New carbon quantum dots (CQDs) with multi-doped elements from eggshell biomass waste have been employed as a direct, fast, green, and selective probe for the fluorometric determination of molnupiravir, a COVID-19 antiviral drug. For the first time, the eggshell@CQDs were prepared through a simple, single-step microwave heating process that only took 90 s. Upon excitation at λex 340 nm, the resulting CQDs exhibited a maximum bluish fluorescence emission at λem 408 nm. Molnupiravir was found to quench the native fluorescence of the prepared CQDs in a quantitative manner, based on a static mechanism by forming a non-emissive complex. The spectrofluorometric method designed for molnupiravir detection was validated per the International Council for Harmonization (ICH) requirements. The proposed fluorescent probe showed good linearity for molnupiravir detection over a range of 2.5–70 µg/mL, with percent recoveries ranging from 99.53 % to 101.79 % and %RSD (relative standard deviation) less than 1 %. The eggshell@CQDs were successfully employed to determine molnupiravir levels in marketed hard capsules, yielding good percent recoveries and repeatability. The developed approach was found to be greener than the published HPLC/UV approach, as assessed by the analytical eco-scale, green analytical procedure index (GAPI), and analytical greenness metric approach (AGREE). Furthermore, this approach highlights the potential of synthesizing CQDs from natural biomass, specifically low-value biomass waste such as eggshells.

Determination of Enantiomer in Tofacitinib Citrate Using Reversed-Phase Chiral High-Performance Liquid Chromatography

Tofacitinib citrate (RR-isomer) is a janus kinase (JAK) inhibitor approved for the treatment of rheumatoid arthritis (RA) in adults who have had an inadequate response or intolerance to methotrexate. The presence of the enantiomer of tofacitinib citrate (SS-isomer) is monitored for quality control as a possible impurity in the final product. In this study, a reversed-phase high-performance liquid chromatography (RP-HPLC) method based on a chiral recognition mechanism for the separation of tofacitinib citrate and its enantiomer was established based on the principles of green analytical chemistry. A CHIRALPAK IH column was used with a mobile phase of ammonium acetate buffer (pH 8.0) and acetonitrile in a gradient elution at a detection wavelength of 285 nm. The calibration curve exhibited excellent linearity over the range of 0.1002–20.04 μg/mL (r = 0.9999). The average recovery of the enantiomer was 98.6% with a relative standard deviation (RSD) of 0.7%. The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.04 and 0.1 μg/mL, respectively. This RP-HPLC method was suitable for detecting the enantiomers of tofacitinib citrate in tablets. Furthermore, the method proved to be environmentally friendly based on the evaluation by Analytical Eco-Scale, Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI).

Greenness appraisal and development of validated spectrophotometric methods for assay of amprolium: Comparative study using Analytical Eco-Scale, GAPI, and AGREEmetric approaches

Intestinal coccidiosis is a serious parasitic disease in poultry. Amprolium hydrochloride(AMP) is widely used for the treatment and prevention of coccidiosis. Three simple and green spectrophotometric methods have been developed for assay of AMP in bulk powder and in dosage form. The first method relies on measuring the first derivative (D1) spectrum at Δλ= 3 nm of AMP. This D1 spectrum possesses a characteristic peak at 234 nm. The second method relies on measuring the difference spectrophotometry (ΔA) and its first derivative (ΔD1) spectra of the drug solutions in 0.1 N HCl against the corresponding solutions in 0.1 N NaOH. The value of amplitudes of ΔA and ΔD1 (∆λ = 3 nm) were measured at 248 and 240 nm, respectively. The third method involves a colorimetric reaction with KMnO4 in alkaline medium and measuring the colored product at 610 nm. The developed methods were validated in accordance with ICH guidelines and evaluated for greenness using three greenness metrics; Analytical Eco-Scale (AES), Analytical GREEness calculator (AGREE), and Green Analytical Procedure Index (GAPI). All proposed methods showed excellent simplicity as they don't require sophisticated instrumentation or tedious analytical procedure steps.

Tri-chromic sustainable tools of derivative/discrete Fourier transform HPLC convoluted peaks: Application on LCZ696, an antihypertensive supramolecular complex, with its in process and degradation impurity analysis

The aim of this manuscript is to discuss the use of chemometrics approaches in handling the response data of HPLC to sustainable analytical chemistry procedure development. This was performed on FDA approved LCZ696, an antihypertensive supramolecular complex of sacubitril (SAC) and valsartan (VAL), with the in process and degradation impurity (BMP). Structure similarity between SAC and its in process and degradation impurity (BMP) makes it difficult for their simultaneous determination and need too much time and solvent consumption for their separation. It was found that convolution of the resulting derivative curves using 8-points sin xi polynomials (discrete Fourier functions) after derivative treatment of the chromatographic response data was beneficial in handling one of the most common chromatographic problems which is overlapping of the chromatographic peaks without complete resolution, thus, reducing time of analysis and solvent consumption. The chemometric data handling succeeded in analyzing LCZ696, with its closely related in process impurity in less than 4.5 min. reaching impurity detection limit of 0.5 % in presence of the parent drug, SAC, while the direct chromatographic measurement showed higher LOD and LOQ of BMP with poor recovery, outside the accepted range 98–102 %, ranging from 80.56 to 104.41. Moreover, the proposed chemometric methodology will be compared with other chromatographic methods in terms of greenness, blueness and whiteness (tri-chromic assessment) using Analytical Eco Scale, AGREE, Blue Applicability Grade Index (BAGI) and the up-to-date Chlortox scale in addition to the white RGB 12 model in order to ascertain the influence of chemometric methods in minimizing the amount of time spent conducting the analysis and reducing solvent, energy and waste consumption.

Eco-Friendly Simultaneous Estimation of Ponceau 4R and Carmoisine Employing an Analytical Quality by Design-Aided RP-HPLC Method in Commercial Food Samples Utilizing a Green Ultrasound-Assisted Extraction Technique.

Ponceau 4R (E124) and carmoisine (CMS; E122) are frequently utilized azo synthetic dyes in the food industry owing to their aesthetically pleasing coloration and broad consumer acceptability. It is imperative to prioritize environmentally favorable technologies for quantifying these dyes, as excessive consumption of these poses significant health risks. The primary objective of this research was to establish a reversed-phase (RP)-HPLC method that could simultaneously detect Ponceau 4R and CMS, implementing green analytical chemistry (GAC) and analytical quality by design (AQbD), using an ultrasound-assisted extraction (UAE) technique in commercial food samples. An Agilent Eclipse Plus column (C18, 250 × 4.6 mm id, 5 µm) was utilized for effective separation with a mobile phase of ethanol-acetate buffer pH 5 (60:40, v/v), flow rate of 1 mL/min, and detection wavelength of 515 nm. Critical variables selected for method optimization were ethanol percentage and flow rate, determined using central composite design (CCD). In order to adhere to the 12 principles of green chemistry, hazardous solvents were substituted with ethanol, which is distinguished by its ease of use, effectiveness, and ecological sustainability. The greenness assessment was conducted utilizing the green analytical procedure index (GAPI), analytical eco-scale (AES), and analytical greenness metrics (AGREE). The respective retention times for Ponceau 4R and CMS were 2.276 and 3.450 min. The recovery rate of Ponceau 4R and CMS fluctuated between 70% and 102% and 80% and 102%, respectively, across various marketed food samples. The procedure passed validation in accordance with the International Conference on Harmonization Q14 guidelines. The devised method demonstrates that the validation parameters like linearity, precision, sensitivity, and reproducibility are within the specified limits of ICH guidelines. The greenness assesment tools GAPI, AES, and AGREE produced the most favorable results. In future, environmentally sustainable, solvent-based, robust AQbD methodologies for assessing varieties of food colorants may be adopted and improved commercially.

Utility of sustainable ratio derivative spectrophotometry for the concurrent assay of synergistic repurposed drugs for COVID-19 infections; Insilico pharmacokinetics proof

The cutting-edge combination of fluvoxamine (FVM) and ivermectin (IVM) has been presented as a proposed dosage form for the treatment of COVID-19 infections in early diagnosed patients. The main objective of this work is to develop simple, sensitive, and efficient methods for the synchronous quantification of FVM and IVM without any prior separation. Four green UV-methods were employed for the synchronous quantification, namely: Fourier functions convolution of absorption spectra, FFAS, Fourier functions convolution of derivative spectra of absorption curves, FFDS, Fourier function convolution of ratio spectra of absorption curves, FFRS and the dual-wavelength method, DWM. FFRS and DWM approaches can be able to reconcile the two components' significantly interfering spectrum presented in this commixture. Good linearity was checked in the range of 5–40, and 2.5–25 μg/mL for the FVM, and IVM, respectively. All approaches developed have been recommended in compliance with ICH principles. Furthermore, the approaches’ greenness was predestined by “National Environmental Method Index” (NEMI), “Analytical GREEnness metric (AGREE)”, the “Analytical Eco-Scale”, and the “Green Analytical Procedure Index” (GAPI). In addition, spider diagram was utilized for the assessment of the greenness index of the solvent used. Beside greenness, the sustainability of our methods was investigated using the HEXAGON tool. Continuing the constant pursuit of greenness, drug-drug interactions (DDIs) between FVM & IVM were predicted by insilico tools to ensure the safety of the suggested mixture as a preliminary step before invitro and in vivo studies. Because they were deemed sustainable, affordable, and successful, the suggested UV-methods may be used for routine quality control investigations of the indicated formulations FVM & IVM.

One-pot Microwave Synthesis of Cobalt, Nitrogen, and Sulfur Co-Doped Carbon Quantum Dots for Efficient Monosodium Glutamate Determination in Food Samples

The synthesis of cobalt, nitrogen and sulfur co doped carbon quantum dots (Co-NS-CQDs) has become a subject of significant research interest. These CQDs were produced using a single-step microwave method, which is considered environmentally friendly, and the entire process was completed in just 90 seconds. In this synthesis, citric acid was utilized as the carbon source, methionine served as the source for both nitrogen and sulfur, and cobaltous acetate was used to introduce cobalt ions into the CQDs structure. The synthesized carbon quantum dots (CQDs) exhibit a narrow size distribution and a high quantum yield of 51.5%, which is notably superior to non-metal-doped CQDs with a yield of 38%. Characterization of these CQDs was performed using different techniques such as transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transformation infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The developed CQDs have blue luminescence at emission wavelength 438 nm after excitation at 350 nm. Different factors affecting the CQDs synthesis including dialysis duration, reaction time and reaction temperature. These CQDs were utilized as a probe for the detection of monosodium glutamate (MSG) in various food products. The intensity of the fluorescence of the CQDs showed a direct and linear increase with the concentration of MSG within the range of 25–250 µg/mL. The detection and quantitation limits for MSG were 2.78 µg/mL and 8.44 µg/mL, respectively. Additionally, the developed method is environmentally friendly, as confirmed by assessments using the analytical Eco scale, Green Analytical Procedure Index (GAPI), and Analytical Greenness calculator (Agree). The proposed method presents several advantages over other reported methods in terms of convenience, rapid response, and attainment of accurate and precise results.

A comparative analysis of univariate versus multivariate eco-friendly spectrophotometric manipulations for resolving severely overlapped spectra of vonoprazan and amoxicillin new combination

Vonoprazan and amoxicillin are pharmacological combinations that demonstrate synergistic effects in treating Helicobacter pylori (H. pylori), a global public health concern associated with peptic ulcer disease and gastric cancer. Four spectrophotometric methods were developed, including two univariate techniques (Fourier self-deconvolution and ratio difference) and two multivariate chemometric approaches (partial least squares and principal component regression). These methods provide innovative solutions for effectively resolving and accurately quantifying the overlapping spectra of vonoprazan and amoxicillin. The concentration ranges covered were 3–60 μg ml−1 for vonoprazan and 5–140 μg ml−1 for amoxicillin. To assess the environmental sustainability of the methodologies, various measures such as the Green Analytical Procedure Index (GAPI), National Environmental Method Index (NEMI), Analytical GREEnness Calculator, and Analytical Eco-scale, as well as RGB12 and hexagon toll were implemented. The validation of the developed techniques was carried out in compliance with ICH standards. The present study is highly significant because it is the first time that the mixture has been determined using the current approaches. The comparative analysis demonstrated no significant difference in terms of accuracy and precision compared to reference HPLC method (p = 0.05). The established spectrophotometric methods offer a straightforward, rapid, and cost-effective alternative to complex analytical techniques for determining the vonoprazan and amoxicillin mixture. They show potential for routine analysis in research laboratories and pharmaceutical industries.

Air-agitated liquid–liquid microextraction method based on solidification of a floating organic droplet (AALLME-SFO) followed by UPLC-MS/MS for trace analysis of steroids in water samples: Assessment of the method environmental impact using Analytical Eco-Scale, green Analytical procedure Index and the Analytical GREEnness metric

In the present study, we developed and optimized an air-agitated liquid–liquid microextraction method, employing the solidification of a floating organic droplet (AALLME-SFO), for the effective and rapid identification of specific steroids in water samples using UPLC-MS/MS. The methodology relies on the utilization of 1-dodecanol as the extractant.Initial microextraction trials were carried out to identify an appropriate study space within the experimental conditions. The factors influencing extraction efficiency, including the type and volume of extractant, sample pH, salt concentration, and centrifugation time, were investigated and optimized using experimental designs. The method was carried out using 1-dodecanol as the extractant solvent, the centrifugation time was 15 min and no requirement for the addition of salt or adjustment of pH. Under optimized conditions, the method exhibited favorable linearity, with correlation coefficients higher than 0.9990. Detection limits fell within the range of 0.0025–0.034 µg/L. The proposed method effectively determined the targeted steroids in water samples, yielding satisfactory recoveries ranging from 90.14 % to 98.90 % and relative standard deviations (RSDs) of ≤ 4.10. The environmental impact of the method was assessed through the Analytical Eco-Scale (AES), Green Analytical Procedure Index (GAPI), and the Analytical GREEnness (AGREE) metric, affirming its ecological compatibility. The AALLME-SFO method, as proposed, offers advantages over established methods for steroid detection in water, such as simple preparation, cost-effectiveness, improved extraction efficiency, and environmental friendliness, establishing it as a practical alternative to conventional methods.

Two green and sensitive spectrofluorimetric approaches for determination of Ambroxol and guaifenesin in their single and combined pharmaceutical formulations.

Ambroxol hydrochloride (AMX) and guaifenesin (GFN) are approved drugs utilized to treat coughs through their potent mucolytic and expectorant properties. Due to their massive, combined administration in many illnesses, there is a persistent need for their concurrent estimation in different pharmaceutical formulations. Two sensitive, environmentally friendly spectrofluorimetric methods were developed. AMX was determined using the first method (I) without interference from GFN. This method depends on the quenching of Erythrosine B (EB) native fluorescence at 552 nm after excitation at 527 nm due to the formation of a non-fluorescent AMX-EB ion-pair complex in Britton-Robinson buffer (BRB) solution pH (3.5). The concentration plot is linear over the 0.25-5.0μg/mL range, with a mean percent found value of 99.74%. Method (II) depends on measuring the native fluorescence of aqueous GFN solution at two analytical wavelengths, either 300 or 600 nm, after excitation at 274 nm. Relative fluorescence intensity (RFI)-concentration plots are linear over the ranges of 0.02-0.5 and 0.1-2.0μg/ml, with mean percent found at 99.96% and 99.91% at dual wavelengths, respectively. The proposed methods were successfully applied to assay both drugs in raw materials and different single and combined pharmaceutical formulations. These methods have been thoroughly validated following International Committee on Harmonisation (ICH) guidelines. National Environmental Methods Index, Analytical Eco-Scale, and Green Analytical Procedure Index were used to prove greenness, thereby enhancing their applicability. The proposed techniques provide straightforward, precise, and cost-effective solutions for routine formulation analysis in quality control laboratories.

Development of the spectrophotometric method for the determination of meldonium in capsules by using alizarine

The aim of the work was to develop a simple, rapid, economic spectrophotometric method for the determination of meldonium in capsules based on the reaction with alizarin.
 Materials and methods. Analytical equipment: double-beam UV-visible spectrophotometer Shimadzu UV 1800 (Japan), a pair of 1 cm matched quartz cells, software UV-Probe 2.62, laboratory electronic balance RAD WAG AS 200/C, pH-meter И-160МИ. Pharmacopoeial standard sample (CRS) of meldonium dihydrate (Sigma-Aldrich, (≥ 98 %, HPLC)), alizarin (Synbias), capsules Metamax (Darnytsia) 250 mg, Vasopro (Farmak) 500 mg, Mildronate (Grindex) 500 mg, dimethylformamide (“Honeywell Riedel-de Haen”).
 Results and discussion. A spectrophotometric method for determining meldonium in capsules by reaction with alizarine has been developed. The absorption maximum of the formed complex in dimethylformamide was at a wavelength of 517 nm. Stoichiometric ratios of reactive components «meldonium- alizarin» were 1:1. Validation of the developed analytical method for the determination of meldonium in medicines was carried out in accordance with the requirements of the SPhU. The optimal conditions for performing the quantitative determination of meldonium have been established: concentration of alizarin solution – 0.8 %, volume 0.8 % alizarin solution – 0.5 ml, heating time – 20 min, temperature – 95+/- 2 °C. Linearity has been in the concentration range of 0.0402- 0.1073 mg/mL, the limit of detection - 2.84 μg/mL, and the limit of quantification – 8.59 μg/mL. The eco-friendliness of the developed analytical method was carried out using the analytical eco-scale, AGREE, and GAPI methods.
 Conclusions. The developed method can be used as an arbitration method for the routine analysis of meldonium capsules

Green Analytical Toxicology procedure for determination of ketamine, its metabolites and analogues in oral fluid samples using dispersive liquid-liquid microextraction (DLLME).

New psychoactive substances (NPS) are often synthesized via small changes in the molecular structure, producing drugs whose effect and potency are not yet fully known. Ketamine is one of the oldest NPS, with therapeutic use in human and veterinary medicine authorized in several countries, being metabolized mainly into norketamine and 6-hydroxy-norketamine. Furthermore, two structural analogues of ketamine have recently been identified, deschloroketamine and 2-fluorodeschloroketamine, marketed as drugs of abuse. To comply with Green Analytical Toxicology (GAT) fundamentals, miniaturized techniques such as dispersive liquid-liquid microextraction (DLLME) were employed to determine toxicants in biological fluids. An analytical method for determining ketamine, its metabolites and its analogues in oral fluid was fully developed and validated by using DLLME and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The extraction parameters were optimized by multivariate analysis, obtaining the best conditions with 200 μL of sample, 100 μL of methanol as dispersive solvent and 50 μL of chloroform as extractor solvent. Linearity was obtained from 10 to 1,000 ng/mL, with limit of detection (LOD) and lower limit of quantification (LLOQ) at 10 ng/mL. Imprecision (% relative standard deviation) and bias (%) were less than 8.2% and 9.5%, respectively. The matrix effect did not exceed 10.6%, and the recovery values varied from 24% to 42%. No matrix interference and good selectivity in the evaluation of 10 different sources of oral fluid and 42 drugs at 500 ng/mL, respectively, were observed. The method was applied in the analysis of 29 authentic oral fluid samples and had its green characteristic evaluated by three different tools: the Green Analytical Procedure Index (GAPI), the Analytical Eco-Scale and the Analytical GREEnness (AGREE) metrics.

Green Chromatographic Assay of Toxic Impurities of Cyproheptadine: In Silico Toxicity Profiling.

Cyproheptadine (CYP) is an antihistaminic and anti-serotonin drug used to improve the clinical course of hospitalized patients severely affected by COVID-19 and requiring supplemental oxygen. Thin layer chromatography (TLC)-densitometry method was developed and validated for the estimation of CYP and its impurity, dibenzosuberone and its degradation product: 10, 11-dihydroxy-dibenzosuberone. The toxicity profiles of CYP impurity and degradation product were studied and the in silico data, using pre-ADMET software, proved their toxicity. A developing system of hexane: methanol: ethyl acetate: formic acid: triethylamine (8:1:1:0.05:0.1, by volume) was used with densitometric scanning at 245nm. International Conference of Harmonization guidelines were obeyed for method validation. The proposed method was applied on CYP pharmaceutical formulation whose results showed no significant difference from results of the reported chromatographic method regarding accuracy and precision. Method's greenness was evaluated by analytical Eco scale, Green Analytical Procedure Index, and Analytical greenness approach tools. The developed method can be applied for safety check analysis of CYP containing formulations and detection and even quantification of its related toxic components in quality control laboratories at high sensitivity up to 20-fold than the reported chromatographic method.

Greenness of dispersive microextraction using molecularly imprinted polymers

Abstract Molecularly imprinted polymers (MIPs) as materials with determined levels of selectivity and specificity for designated analytes have recently gained much attention in various application fields. However, with the growing adoption of green analytical chemistry (GAC) principles, it is essential to investigate the greenness of MIP synthesis and its subsequent application in sample preparation, as well as to evaluate the “green” nature of the developed analytical methodologies, such as dispersive solid-phase microextraction (DSPME). Accordingly, the main objective of this research was to evaluate the greenness of MIP-based glycidyl methacrylate synthesis and MIP use as a DSPME sorbent prior to high-performance liquid chromatography with mass spectrometry (HPLC-MS). The green perspective of MIP-DSPME prior to HPLC-MS was investigated using various analytical metric tools such as the Analytical Eco-Scale, the Green Analytical Procedure Index, and Analytical GREEnness (AGREE). Since these analytical tools are not fully implementable for the assessment of the greenness of the MIP synthesis, some alternative approaches were used to optimize the synthesis parameters to make the MIP DSPME sorbent as close as possible to the GAC principles. The calculated AGREE score (0.62) and 91 points in the Analytical Eco-Scale for the proposed DSPME technique using MIP indicated a high level of greenness.