Application of NEMI, Analytical Eco-Scale and GAPI tools for greenness assessment of three developed chromatographic methods for quantification of sulfadiazine and trimethoprim in bovine meat and chicken muscles: Comparison to greenness profile of reported HPLC methods

Green method by National Environmental Methods Index and Eco-Scale Assessment for evaluation of gatifloxacin-based product by HPLC

The literature reveals gaps in the availability of green analytical methods for assessing products containing gatifloxacin (GFX), a fluoroquinolone. Presently, method development is supported by tools such as the National Environmental Methods Index (NEMI) and Eco-Scale Assessment (ESA), which offer objective insights into the environmental friendliness of analytical procedures. The objective of this work was to develop and validate a green method by the NEMI and ESA to quantify GFX in eye drops using HPLC. The method utilized a C8 column (4.6 × 150 mm, 5 μm), with a mobile phase of purified water containing 2% acetic acid and ethanol (70:30, v/v). The injection volume was 10 μL and the flow rate was 0.7 mL/min in isocratic mode at 25°C, with detection performed at 292 nm. The method demonstrated linearity in the range of 2-20 μg/mL, and precision at intra-day (relative standard deviation [RSD] 1.44%), inter-day (RSD 3.45%), and inter-analyst (RSD 2.04%) levels. It was selective regarding the adjuvants of the final product (eye drops) and under forced degradation conditions. The method was accurate (recovery 101.07%) and robust. The retention time for GFX was approximately 3.5 min. The greenness of the method, as evaluated by the NEMI, showed four green quadrants, and by ESA, it achieved a score of 88.

Cutting-edge HPLC and MCR techniques for synchronically quantifying anticholinergic drugs in the presence of C12 and C14 homologs: Robust application to green and white chemistry

Green and white chemistry are vital to revolutionizing the chemical industry through their unparalleled potential to enhance sustainability and efficiency. In this study, nine sustainability tools of both green and white metrics, including green analytical procedure index (GAPI), ComplexGAPI, analytical greenness, analytical greenness metric for sample preparation, Analytical Eco-Scale (ESA), analytical method greenness score, high-performance liquid chromatography- environmental assessment tool (HPLC-EAT), analytical method volume intensity, and blue applicability grade index (BAGI), have been developed for appraising environmental friendliness for both innovative and straightforward mean centering of ratio spectra (MCR) and reversed-phase high-performance liquid chromatography (RP-HPLC) strategies utilized for concurrent analysis and separation of cyclopentolate (CYC) and C12 and C14 homologs of benzalkonium chloride (BNZ) in pure and ophthalmic solution. The mobile phase, formed of buffer phosphate and acetonitrile (35:65, v/v), was adjusted to pH 6.3, and 215-nm UV detection was used. The experimental flow rate was 2.0 mL min-1, and the analytical column was L11 Inertsil Ph-3 (150 mm × 4.6 mm, 5 µm). All sequences were run at 25°C in the column oven. The MCR approach effectively resolved the drug's spectral overlapping. CYC and BNZ employed this approach at 227.5 and 220.4 nm, respectively. As part of the HPLC analysis, an isocratic method was employed with phosphate buffer and acetonitrile in the mobile phase at 35:65. A correlation coefficient greater than 0.999 was observed between the calibration curves for the HPLC and MCR methods in the ranges of 20-320 µg mL-1 and 5-30 µg mL-1 for all drugs. The technique yields excellent primary recovery rates, ranging from 97.2% to 100.5%. The recommended approach has been validated according to International Council for Harmonization guidelines.

Functionalized fennel extract-mediated alumina/cerium oxide nanocomposite potentiometric sensor for the determination of diclofenac sodium medication

The current work suggests a new, ultrasensitive green functionalized sensor for the determination of anti-inflammatory medication diclofenac sodium (DCF). Alumina (Al2O3) and cerium oxide (CeO2) nanoparticles (NPs) have attracted great interest for their use as outstanding and electroactive nanocomposite in potentiometric and sensory research due to their ultrafunctional potential. The formed nanoparticles have been confirmed using various spectroscopic and microscopic techniques. The fennel extract-mediated Al2O3/CeO2 nanocomposite (Al2O3/CeO2 NCS) modified coated wire membrane sensor developed in this study was used to quantify DCF in bulk and commercial products. Diclofenac sodium was coupled with phosphomolybdic acid (PMA) to generate diclofenac phosphomolybdate (DCF-PM) as an active ion-pair in the existence of polyvinyl chloride (PVC) and o-nitrophenyl octyl ether (o-NPOE). Clear peaks at 270, and 303 nm with band gaps of 4.59 eV and 4.09 eV were measured using UV-vis spectroscopy of Al2O3 and CeO2, respectively. The crystallite sizes of the formed nanoparticles were XRD-determined to be 30.13 ± 8, 17.72 ± 3, and 35.8 ± 0.5 nm for Al2O3, CeO2, and Al2O3/CeO2 NCS, respectively. The developed sensor showed excellent response for the measurement and assay of DCF, with a linearity between 1.0 × 10-9 and 1.0 × 10-2 mol L-1. EmV = (57.76) log [DCF] +622.69 was derived. On the other hand, the typical type DCF-PM presented a potentiometric response range of 1.0 × 10-5-1.0 × 10-2 mol L-1 and a regression equation of EmV = (56.97) log [DCF]+367.16. The functionalized sensor that was proposed was successful in determining DCF in its commercial tablets with percent recovery 99.95 ± 0.3. Method validation has been used to improve the suitability of the suggested potentiometric technique, by studying various parameters with respect to the international council harmonization requirements for analytical methodologies.

What Are We Eating? Surveying the Presence of Toxic Molecules in the Food Supply Chain Using Chromatographic Approaches

Consumers in developed and Western European countries are becoming more aware of the impact of food on their health, and they demand clear, transparent, and reliable information from the food industry about the products they consume. They recognise that food safety risks are often due to the unexpected presence of contaminants throughout the food supply chain. Among these, mycotoxins produced by food-infecting fungi, endogenous toxins from certain plants and organisms, pesticides, and other drugs used excessively during farming and food production, which lead to their contamination and accumulation in foodstuffs, are the main causes of concern. In this context, the goals of this review are to provide a comprehensive overview of the presence of toxic molecules reported in foodstuffs since 2020 through the Rapid Alert System for Food and Feed (RASFF) portal and use chromatography to address this challenge. Overall, natural toxins, environmental pollutants, and food-processing contaminants are the most frequently reported toxic molecules, and liquid chromatography and gas chromatography are the most reliable approaches for their control. However, faster, simpler, and more powerful analytical procedures are necessary to cope with the growing pressures on the food chain supply.

Green chemical analysis: main principles and current efforts towards greener analytical methodologies

Green chemistry, green analytical chemistry and green sample preparation are related areas that have been developing since the 90s, aiming to moderate the adverse impacts of chemical practices on the environment and human health. Presently, a set of green principles has been established, which is a collection of rules that need to be followed to perform chemical practices with a lower negative impact on the environment. Herein, we comprehensively review green chemical analysis by combining historical aspects and ongoing efforts of green analytical methodologies. Through four systematically designed chapters, information is presented on the aspects of green analytical chemistry, including its fundamentals, metrics, modern strategies and future trends.

Utility and greenness appraisal of nuclear magnetic resonance for sustainable simultaneous determination of three 1,4-benzodiazepines and their main impurity 2-amino-5-chlorobenzophenone

A robust, stability-indicating, and eco-friendly proton nuclear magnetic resonance (1H-qNMR) method was developed for the concurrent determination of three 1,4-benzodiazepines (BDZs), namely diazepam (DZP), alprazolam (ALP), and chlordiazepoxide (CDP) and their common impurity, synthesis precursor, and degradation product; 2-amino-5-chlorobenzophenone (ACB). In the present method, a novel approach was developed for composing a green and cost-efficient solvent system as an alternative to the common NMR organic solvents utilizing 0.3 M sodium dodecyl sulfate prepared in deuterated water. The conducted method is characterized by simplicity with no need for sample pretreatment or labeling. Phloroglucinol was used as an internal standard. The chosen signals for the determinations of ALP, CDP, DZP and ACB were at 2.35 ppm (singlet), 2.84 ppm (singlet), 3.11 ppm (singlet), and 6.90 ppm (doublet of doublet), respectively. The proposed method possessed linearity over the concentration range of 0.25-15.0 mg ml-1 for DZP, ALP, CDP and of 0.5-25.0 mg ml-1 for ACB with LOD values of 0.06, 0.03, 0.07 and 0.16 mg ml-1 respectively, and LOQ values of 0.18, 0.09, 0.21 and 0.49 mg ml-1, respectively. Accuracy of the method was evidenced by excellent recovery% (99.57-99.90%) and small standard deviation (≥ 1.10) for the three analyzed drugs. Intra- and inter-day precision were determined with coefficient of variation ranging from 0.12 to 1.14 and from 0.72 to 1.67, respectively. For the studied compounds, appraisal of the method greenness was achieved via four approaches: Analytical Eco-Scale, Green Analytical Procedure Index (GAPI), Analytical greenness metric (AGREE), and RGB Additive Color Model. The results proved that the proposed method has the privilege of being a green analytical method.

An innovative combination of Box-Behnken design and ecofriendly approaches for the simultaneous determination of aspirin, clopidogrel, atorvastatin and rosuvastatin in their fixed-dose combination tablets

Three-levels Box-Behnken design was used in the experimental design approach for the optimization of chromatographic parameters to achieve the optimum resolution and sharp peak shape within a reasonable run time. A method that is sensitive, reliable, and selective was constructed and validated for the simultaneous measurement of a combination therapy that contains blood-thinning and cholesterol-lowering compounds. The four cited drugs namely, aspirin (ASP), clopidogrel (CLP), atorvastatin (ATV) and rosuvastatin (ROS) were estimated in bulk and in pharmaceutical dosage forms in line with International Council for Harmonization guidelines. The separation was done utilizing Kinetex 2.6 C18 column (100 mm, 4.6 mm, 5 m) and RP-HPLC with diode array detector. The separation of the cited drugs and the degradation product of ASP was achieved with mobile phase composed of acetonitrile: KH2PO4 buffer in a gradient mode with pH 3.2 at room temperature. The four drugs were linear over the concentration range (0.05-50 µg/mL). The technique is feasible to be used in quality control laboratories. To picture the green profile of the developed method, four greenness assessment tools were applied. National environmental methods index (NEMI), analytical eco-scale assessment (ESA), green analytical procedure index (GAPI) and analytical greenness metric (AGREE) are the most widely used metrics. They were employed to evaluate the greenness profile of the proposed method and to perform a detailed greenness comparison between the developed method and some of the reported methods for the determination of the investigated drugs. The developed method was found to be relatively green with 0.54 AGREE score.

Green UPLC method for estimation of ciprofloxacin, diclofenac sodium, and ibuprofen with application to pharmacokinetic study of human samples

Investigation of a unique and fast method for the determination and separation of a mixture of three drugs viz., ciprofloxacin (CIP), Ibuprofen (IBU), and diclofenac sodium (DIC) in actual samples of human plasma. Also, the technique was used to look at their pharmacokinetics study. Hydrocortisone was chosen as the internal standard (IS). The drugs were chromatographically separated using an Acquity ultra-performance liquid chromatography UPLC ® BEH C18 1.7 µm (2.1 × 150 mm) column with a mobile phase composed of acetonitrile: water (65:35, v/v) adjusted to pH 3 with diluted acetic acid. Plasma proteins were precipitated with acetonitrile. The separated drugs ranged from 0.3 to 10, 0.2-11, and 1-25 µg/mL for CIP, IBU, and DIC, respectively. Calibration curves were discovered to achieve linearity with acceptable correlation coefficients (0.99%). Examination of quality assurance samples showed exceptional precision and accuracy. Following the successful application of this improved technique to plasma samples, the pharmacokinetic characteristics of each selected drug were evaluated using (UPLC) with UV detection at 210 nm. Two green metrics were applied, the Analytical Eco-scale and the Analytical GREEnness Calculator (AGREE). Separation was achieved in only 4-min analysis time. The method's validation agreed with the requirements of the FDA, and the results were sufficient.

AGREE and ESA for Greenness Assessment of a Novel Validated RP-HPLC Method for Simultaneous Determination of Aspirin, Warfarin and Clopidogrel in Rat Plasma: Application to Pharmacokinetic Study of the Possible Interaction between the Three Drugs

The green profile of the developed method is assessed and compared with previously reported methods. Percutaneous coronary intervention is a procedure where a catheter is utilized to place a stent in order to facilitate opening of the blood vessels in the heart. Triple antithrombotic therapy includes oral anticoagulation as warfarin and dual antiplatelet therapy (composed of aspirin and clopidogrel bisulfate). The aim of the current study was to evaluate the pharmacokinetic parameters of ASP, WAR and CLP and to investigate the possible interaction between the three drugs upon co-administration in rats. A selective and precise RP-HPLC method was developed for the simultaneous determination of ASP, WAR and CLP in rat plasma. Pharmacokinetic study was conducted in rats that received ASP, WAR and CLP as an application of the developed method. From the statistical evaluation of the pharmacokinetic parameters, it was observed that the co-administration of ASP, WAR and CLP significantly increased the ASP and CLP bioavailability in rats. A significant drug-drug interaction was confirmed in the current study. The elevated Cmax of ASP and CLP upon the co-administration of ASP, WAR and CLP may explain the reported bleeding.

Development and validation of an effective and sensitive technique for nitrate determination in fruits and vegetables using HPLC/PDA

This study aims to develop an effective and sensitive HPLC (High Performance Liquid Chromatography) method to determine the nitrate concentration in fruits and vegetables (F & V) using a C18 column (ZORBAX Eclipse XDB-C18, 80Å, 250 × 4.6 mm, 5 μm (Agilent Technologies)) maintained at 40 0 C, a mobile phase made up of methanol and buffer (pentane sulfonic acid sodium salt solution), and a Photo Diode Array Detector (PDA) at 225 nm. The developed method is validated in terms of selectivity, linearity, accuracy, precision, suitability, the limit of detection (LOD), and the limit of quantification (LOQ) according to the European Union Decision 2002/657/EC. The result revealed that a ratio of 30: 70 of the organic modifier methanol and buffer with pH 2.8 shows the highest efficiency. The calibration curve shows linearity with a correlation coefficient (r) of 0.9985. The LOD and LOQ were found to be 2.26 mg/kg and 7.46 mg/kg. The recovery was in the range of 98.96-100.21%. Moreover, the greenness assessment scores of different approaches (eco-scale score of 76, AGREE score of 0.71, and few red shades in GAPI portray) were at a very excellent level. Thus, our developed method is fully validated and can determine the nitrate content in F & V.

A Comparative Analysis on the Environmental Impact of Selected Methods for Determining the Profile of Fatty Acids in Cheese

The fatty acid profile of cheese influences its sensory parameters, such as color, texture, or flavor. Examining the fatty acid profile also helps to assess the nutritional value of the cheese that is being tested. However, the determination of fatty acids in cheese samples is a multi-stage and time-consuming task. In addition, large amounts of toxic organic solvents are used to prepare samples for analysis purposes. This paper presents the results of a study to determine the fatty acid profile of yellow cheese samples. Six different methods of sample preparation were compared for analysis purposes. The profile of fatty acids was determined using gas chromatography with flame ionization detection (GC-FID). The study showed significant differences (p > 0.05) in the resulting fatty acid profile between the methods used. It was found that the most reliable fatty acid profile results were obtained using methods derived from the Folch method. In addition, tools such as the Analytical Eco-Scale tool and the Analytical Greenness Metric for Sample Preparation (AGREEprep) tool were used to assess the greenness of the methods used. In the case of the Analytical Eco-Scale tool, all six methods scored 'acceptable green analysis' with scores ranging from 61 to 73. However, an evaluation of methods using the AGREEprep metric showed that the results of the methods (0.13-0.27) did not show the "greenness" of the analytical methods.

UPLC-MS/MS Method for Simultaneous Estimation of Neratinib and Naringenin in Rat Plasma: Greenness Assessment and Application to Therapeutic Drug Monitoring

Tyrosine kinase inhibitors have often been reported to treat early-stage hormone-receptor-positive breast cancers. In particular, neratinib has shown positive responses in stage I and II cases in women with HER2-positive breast cancers with trastuzumab. In order to augment the biopharmaceutical attributes of the drug, the work designed endeavors to explore the therapeutic benefits of neratinib in combination with naringenin, a phytoconstituent with reported uses in breast cancer. A UPLC-MS/MS method was developed for the simultaneous estimation of neratinib and naringenin in rat plasma, while imatinib was selected as the internal standard (IS). Acetonitrile was used as the liquid extractant. The reversed-phase separation was achieved on a C18 column (100 mm × 2.1 mm, 1.7 µm) with the isocratic flow of mobile phase-containing acetonitrile (0.1% formic acid) and 0.002 M ammonium acetate (50:50, % v/v) at flow rate 0.5 mL·min−1. The mass spectra were recorded by multiple reaction monitoring of the precursor-to-product ion transitions for neratinib (m/z 557.138→111.927), naringenin (m/z 273.115→152.954), and the IS (m/z 494.24→394.11). The method was validated for selectivity, trueness, precision, matrix effect, recovery, and stability over a concentration range of 10–1280 ng·mL−1 for both targets and was acceptable. The method was also assessed for greenness profile by an integrative qualitative and quantitative approach; the results corroborated the eco-friendly nature of the method. Therefore, the developed method has implications for its applicability in clinical sample analysis from pharmacokinetic studies in human studies to support the therapeutic drug monitoring (TDM) of combination drugs.

Novel Deconvoluted Synchronous Spectrofluorimetric Method For Simultaneous Determination Of Bisoprolol and Atorvastatin As Single or Co-administrated Drugs in Bulk and Plasma; Green Assessment

Atorvastatin and bisoprolol are two medications often prescribed together for the management of cardiovascular disease and to reduce mortality. Through a simple and direct technique based on deconvolution and synchronous of the spectrofluorometric spectra, the innovative method enables simultaneous quantification of bisoprolol and atorvastatin as single or co-formulated dosage forms in bulk and plasma. The method depends on measuring the amplitudes of bisoprolol and atorvastatin at 298 nm and 363 nm directly after deconvolution where the other drug doesn't show interference. The linearity of the method was 0.02-0.5 µg/mL and 0.3-25 µg/mL for bisoprolol and atorvastatin, respectively. LOD and LOQ were 0.004, 0.085 µg/mL and 0.013, 0.259 µg/mL for bisoprolol and atorvastatin respectively. Furthermore, green assessment of the method using Eco-Scale and GAPI scale. The method was precise, economical, simple, smart, time-saving and eco-friendly, which allowed its application in quality control unit and in lab assessment.

Tools to Evaluate the Eco-efficiency of Analytical Methods in the Context of Green and White Analytical Chemistry: A Review

BACKGROUND

The release of a product in the consumer market requires an analysis by quality control. This sector makes use of reliable analytical methods, by high performance liquid chromatography (HPLC), spectrophotometry in the ultraviolet and visible regions (UV-Vis), spectrophotometry in the infrared region (IR) or thin layer chromatography (TLC), for example, to reach a result. The analysis conditions of most of these analytical methods currently still use toxic reagents, generate a greater amount of waste, sample preparation has more steps, the need for instrumentation and consumables in greater quantity, generating a cost and impact on health and the environment greater than if there were adoption of the Green Analytical Chemistry (GAC) and the White Analytical Chemistry (WAC).

OBJECTIVE/METHODS

The objective of this review is to show the relationship of analytical choices for current pharmaceutical analyzes with the GAC and the WAC.

RESULTS

Analytical methods can be evaluated for greenness and whiteness using tools such as the National Environmental Method Index (NEMI), Eco-Scale Assessment (ESA), Analytical Greenness Metric (AGREE) and Green Analytical Procedure Index (GAPI).

CONCLUSION

The use of NEMI, ESA, AGREE and GAPI tools brings the objective evidence needed to discuss the greenness and whiteness of an analytical method, leaving the subjective level. Furthermore, semi or quantitative data facilitate the choice of an analytical method and its conditions, when the target is the concern with eco-efficiency.

Comparison of the Effectiveness and Environmental Impact of Selected Methods for the Determination of Fatty Acids in Milk Samples

Determination of the fatty acid profile in milk samples is one of the most important in food analysis. There are many methodologies for FA determination. The conventional procedure for determining the FA composition of milk is isolation of fat or indirect methylation, trans-methylation, extraction of fatty acids, and analysis by gas chromatography. In this study, eight methods based on alkaline methylation were compared for the analysis of fatty acids in cow's milk. The response factors (RF) for GC analysis using FID were calculated. For most acids, RFs were close to 1, with the exception of short-chain fatty acids (C4:0-C8:0). To facilitate the selection of the method for the determination of fatty acids in milk samples, the methods were assessed using the environmental assessment tools of the analytical procedure: the Analytical Eco-Scale, Green Analytical Procedure Index (GAPI), and Analytical Greenness for Sample Preparation (AGREEprep). The method based on direct milk methylation received the highest scores. Omitting the lipid separation step has an impact on reducing the quantity of used toxic chemicals and reagents, and produces a smaller amount of waste, a much higher throughput, and a reduced cost analysis.

AQbD based green UPLC method to determine mycophenolate mofetil impurities and Identification of degradation products by QToF LCMS

We report an ideal method for quantifying impurities in mycophenolate mofetil drug substances and their oral suspension preparations. We developed a systematic and eco-friendly analytical approach utilizing quality by design (QbD) and green chemistry principles. Initially, the critical method parameters (CMPs) were screened using a D-optimal design. The robust final method conditions were optimized using a systematic central composite design (CCD). Through graphical and numerical optimization, the protocol conditions were augmented. The pH of mobile phase buffer (25 mM KH₂PO₄) (MP-A), initial gradient composition (% MP-A), flow rate (mL min^-1), and column oven temperatures (°C) are 4.05, 87, 0.4, and 30, respectively. The best possible separation between the critical pairs was achieved while using the Waters Acquity UPLC BEH C₁₈ (100 × 2.1) mm, 1.7 µm analytical column. A mixture of water and acetonitrile in the ratio of 30:70 (v/v) was used as mobile phase-B for the gradient elution. The analytical method was validated in agreement with ICH and USP guidelines. The specificity results revealed that no peaks interfered with the impurities and MPM. The mean recovery of the impurities ranged between 96.2 and 102.7%, and the linearity results r > 0.999 across the range of LOQ - 150%. The precision results (%RSD) ranged between 0.8 and 4.5%. The degradation products formed during the base-induced degradation were identified as isomers of mycophenolic acid and sorbitol esters using Q-ToF LC-MS and their molecular and fragment ion peaks. The developed method eco-friendliness and greenness were assessed using analytical greenness (AGREE), green analytical procedure index (GAPI), and analytical eco score, and found it is green.

Analytical quality by design based on design space in reversed-phase-high performance liquid chromatography analysis for simultaneous estimation of metformin, linagliptin and empagliflozin

Employing the Quality by Design paradigm through this work helped conclude the method operable design region for optimizing the high performance liquid chromatography (HPLC) assay using Design of Experiments and response surface methodology to obtain a good resolution and determination of all analysed compounds and to achieve a suitable analysis time. A deep understanding of the quality target product profile, analytical target profile and risk assessment for parameters that affect the method performance led to developing an accurate, precise and cost-effective method. Quality risk management principles were applied for determining the critical method parameters affecting the simultaneous determination of metformin hydrochloride (MET), linagliptin (LIN) and empagliflozin (EMP) by reversed-phase HPLC . The ternary mixture was successfully resolved in 5 min with a linearity range of (0.1-600) µg ml^-1 for MET and (0.05-50) µg ml^-1 for LIN and EMP. The newly developed method was validated according to the International Council for Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. Good agreement was observed with the assay results of the reported UPLC one. To evaluate the greenness of the proposed method, an analytical Eco-Scale method was used.

Green HPLC method with time programming for the determination of the co-formulated eye drops of tafluprost and timolol in their challengeable ratio

A new, simple and selective HPLC method was implemented for the simultaneous estimation of tafluprost (TFL) and timolol (TIM) in their new anti-glaucoma combination in the challengeable ratio of 3 and 1000 for TFL and TIM, respectively. Separation was achieved using a BDS Hypersil phenyl column and a mobile phase made up of acetonitrile: 0.015 M phosphate buffer (50:50 v/v, pH 3.5) delivered at 1 mL min⁻¹ and the separation was completed in less than 6 min. UV detection was time programmed at 220 nm for the first 4.5 min and later at 254 nm. Mebeverine (MEB) was used as an internal standard (I.S.). The linearity was observed in the ranges of 0.6–45 and 50–2000 µg mL⁻¹ with limits of detection (LOD) of 0.18, 16.48 µg mL⁻¹ and limits of quantification (LOQ) of 0.55, 49.94 µg mL⁻¹ for TFL and TIM, respectively. The method satisfied International Council for Harmonization (ICH) validation guidelines. The study was extended to the estimation of the studied drugs in their co-formulated eye drops as well as in their single dosage forms with acceptable percentage recoveries. Moreover, Green Analytical Procedure Index (GAPI) and analytical Eco-scale were investigated to confirm the greenness of the proposed HPLC method.

A QBD and green liquid chromatography technique for the determination of mast cell stabilizer and histamine receptor antagonist (Olopatadine HCl) in multiple formulations

Mast cell stabilizer and histamine receptor antagonist Olopatadine hydrochloride (OPT) assay method predicated on liquid chromatography have been established for the analysis in multiple formulations. The current method dealt with ophthalmic solution, nasal spray, and tablet formulation products. The isocratic chromatography method was optimized and validated with Boston green C8 (150 x 4.6) mm, 5 μm column. Sodium dihydrogen phosphate pH 3.5 buffer with acetonitrile in the ratio of 75:25 (v/v) as a mobile phase with a flow rate of 1.0 mL min^-1 , column temperature 30 °C, and the detection was done at 299 nm. The method was validated as per ICH guidelines and USP. The accuracy results were ranged from 99.9 % to 100.7 %, obtained % RSD from the precision was 0.5, and correlation coefficient from the linearity experiment was > 0.999. Solution stability was established for 24 hrs at room temperature and refrigerator conditions and found that the solutions were stable. Using quality by design-based experiments design, critical quality attributes were studied and established the robust method conditions. All the forced degradation studies peak purity was passed and found no interference at the retention time of the active component. The method validation data dictated that the developed method is linear, precise, accurate, specific, robust, and stable for the determination of OPT from multiple formulations. Analytical Eco-scale tool, modern technique green analytical procedure index (GAPI) tool, and ancient tool national environmental method index (NEMI) were used to evaluate the greenness of the method, and the analytical eco-score of 77 for the presented method was found to be excellent.

Miniaturized green sample preparation approaches for pharmaceutical analysis

The development of green sample preparation procedures is an extremely important research field in which more and more applications are constantly being proposed in different areas, including pharmaceutical analysis. This review article is aimed at providing a general overview of the development of miniaturized green analytical sample preparation procedures in the pharmaceutical analysis field, with special focus on the works published between January 2017 and July 2021. Particular attention has been paid to the application of environmentally friendly solvents and sorbents as well as nanomaterials or high extraction capacity sorbents in which the solvent volumes and reagents amounts are drastically reduced, with their subsequent advantages from the sustainability point of view.

Greenness Assessment of Two Validated Stability Indicating Chromatographic Methods for Estimating Modafinil Using Analytical Eco-Scale

BACKGROUND

Modafinil (MDF) is one of the drugs that used for the treatment of narcolepsy.

OBJECTIVE

This manuscript involves the development and validation of two chromatographic stability indicating methods for MDF in the presence of its acid induced degradation.

METHODS

Modafinil was degraded under different stress conditions and identification of the degradation product was performed using infrared and mass spectroscopy. The first method was thin layer chromatography where aluminum backed silica gel 60F254 plates were used and the developing system was dichloromethane- methanol (9:1, v/v). While the second method was an eco- friendly (HPLC) that utilized C-18 column and ethanol- H2O (30:70, v/v) as a mobile phase at flow rate 1 mL/min and UV detection at 220 nm.

RESULTS

Good linear relationships were obtained within ranges of (1-10 µg/band) and (2-10 µg/mL) for TLC-densitometry and HPLC, respectively. The obtained results were statistically compared with those of the official HPLC method and showed no significant difference with respect to their accuracy and precision at p = 0.05. Greenness scores represent excellent green analysis in comparison with the reported studies.

CONCLUSIONS

The proposed methods were validated according to ICH guidelines and were applied on bulk powder and pharmaceutical dosage form using eco-friendly mobile phases as the worldwide trend.

HIGHLIGHTS

Chromatographic methods have been validated for estimation of MDF in the presence of its degradation product. Clarification of degradation pathway and the elucidation of the structure were stated for the first time. It's the first published method using greenness assessment metrics for the analysis of MDF.

A validated liquid chromatography-tandem mass spectrometric method for the determination of co-administered ranitidine and metronidazole in plasma of human volunteers

This work describes the development, optimization and validation of a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for the simultaneous analysis of co-administered ranitidine (RAN) and metronidazole (MET) in plasma of healthy human volunteers. A simple protein precipitation procedure using 1 mL acetonitrile was applied to extract both drugs and metoclopramide as an internal standard (IS) from plasma. The chromatographic separation was achieved on a C₁₈ column with isocratic elution of the mobile phase consisting of acetonitrile and 0.1% formic acid (90 : 10, v/v) at a flow rate of 0.35 mL min^-1. The positive ionization mode was used for detecting the ions, by observing the pairs of transition m/z 314.82 < 176.06 for RAN, m/z 172.03 < 127.95 for MET and m/z 299.86 < 277.10 for IS. The linearity range was from 5-600 ng mL^-1 for RAN and 2-40 μg mL^-1 for MET. The method was found to be sensitive and accurate with good simple extraction recovery and matrix effect, according to FDA guidelines for bioanalytical methods. The developed method could be applied for further bioavailability studies that could be useful in therapeutic drug monitoring.

Analysis of Cultivable Microbial Community during Kimchi Fermentation Using MALDI-TOF MS

Kimchi, a traditional Korean fermented vegetable, has received considerable attention for its health-promoting effects. This study analyzes the cultivable microbial community in kimchi fermented at different temperatures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to comprehensively understand the factors affecting the quality of kimchi. Of the 5204 strains isolated from kimchi, aligned with the in-house database, 4467 (85.8%) were correctly identified at the species level. The fermentation temperature affected the microbial community by varying the pH and acidity, which was mainly caused by temperature-dependent competition between the different lactic acid bacteria (LAB) species in kimchi. LAB, such as Levilactobacillus (Lb.) brevis and Lactiplantibacillus (Lpb.) plantarum associated with rancidity and tissue softening, proliferated faster at higher temperatures than at low temperature. In addition, LAB, such as Latilactobacillus (Lat.) sakei and Leuconostoc (Leu.) mesenteroides, which produce beneficial substances and flavor, were mainly distributed in kimchi fermented at 4 °C. This study shows as a novelty that MALDI-TOF MS is a robust and economically affordable method for investigating viable microbial communities in kimchi.

Green reversed-phase HPLC development strategy: Application to artesunate and amodiaquine analysis

A green analytical chemistry strategy is described to develop a reversed-phase high-performance liquid chromatography method for amodiaquine and artesunate analysis using ethanol-based mobile phases. This method development was particularly challenging due to the basicity of amodiaquine and low UV absorption of artesunate, leading to peak asymmetry and detection issues, respectively. UV detection concern was even more challenging due to the baseline drift observed with ethanol in gradient mode. Several green pH modifiers were selected for their ecofriendly character and their impact on peak shape and detection was investigated. The screening of various stationary phases (19 columns) appeared as a relevant and necessary approach to reach satisfactory peak shape of basic compounds. To support the results of this study, some additional compounds related to artesunate and amodiaquine structures were included. Methods were optimized and validated using total error approach with a mobile phase composed of ethanol and 10 mM formic acid using three different stationary phases from different manufacturers, providing flexibility of the quality control approach. Method greenness was assessed using the National Environmental Methods Index, the Green Analytical Procedure Index, and the Analytical Eco-Scale. Finally, artesunate and amodiaquine were successfully analyzed in fixed dose combination tablets.