Enhancing the Sustainability of Eco-friendly Potentiometric Ion Selective Electrodes for Stability-Indicating Measurement of Ethamsylate: Application in Bulk and Pharmaceutical Formulations.

BACKGROUND: Through the use of sustainable and green chemistry concepts, scientists need to decrease waste, conserve energy, and develop safe substitutes for hazardous compounds, all for protecting and benefiting society and the environment. OBJECTIVE: Four novel eco-friendly ion selective electrodes (ISE) were created to determine Ethamsylate (ETM) in bulk powder and different pharmaceutical formulations. The present electrodes were fabricated and evaluated to clearly distinguish ETM from a variety of inorganic, organic ions, sugars, some common drug excipients and the degradation product, hydroquinone (HQ) of ETM, and thus could be used for stability-indicating methods. METHODS: The electrodes fabrication was based on 2-nitrophenyl octyl ether (NPOE) that was employed as a plasticizer in electrodes 1, 2, and 3 within a polymeric matrix of polyvinyl chloride (PVC) except for electrode 4, in which dibutyl sebacate was used as a plasticizer. Electrodes 1 & 2 were fabricated using tetra dodecyl ammonium bromide as an anionic exchanger and adding 4-sulfocalix-8-arene as an ionophore only to electrode 2, but electrode 1 prepared without incorporation of an ionophore. The fabrication of electrodes 3 & 4 was based on ethamsylate-tetraphenylborate (ETM-TPB) as an ion-association complex in a PVC matrix. The environmental sustainability was assessed using Green Analytical Procedure Index (GAPI), and Analytical Greenness Metric for Sample Preparation (AGREEprep). RESULTS: Electrodes 1 & 2 had linear dynamic ranges of (10-1-10 -5) and (10-1-10 -4) respectively, with a Nernstian slope of 49.6 and 53.2 mV/decade, respectively. Electrodes 3 & 4 had linear dynamic ranges of (10-1-10 -4), with a Nernstian slope of 43.9 and 40.2 mV/decade, respectively. CONCLUSION: The generated electrodes' selectivity coefficients showed good selectivity for ETM. The utility 4-sulfocalix-8-arene as ionophore had a significant influence on increasing the membrane sensitivity and selectivity of electrode 2 compared to other electrodes.

Smartphone based colorimetric point-of-care sensor for abused drugs: case of baclofen determination in urine.

As a GABA-ß receptor agonist, the central muscle relaxant Baclofen (BAC) has a potential of abuse. Unfortunately, the sense of wellbeing and pleasure is obtained at very high BAC doses. This is associated with many life-threating or even fatal cases due to neurological and respiratory failures. Moreover, having narrow therapeutic index makes BAC a high-risk drug. This is potentiated in case of long-treatment regimen or off-label use in smoking and alcohol cessation protocols. Until now, there is no rapid diagnostic test available for BAC screening. Therefore; It is quite difficult to routinely monitor cases on BAC regimen. On the other hand, smartphone-based colorimetric point of care testing (POCT) is displacing conventional analytical approaches in the detection and assay of abused drugs as well as therapeutic drug monitoring. It offers on-site, rapid, easy, affordable and interpretable analysis. Incorporating smartphone as a portable device facilitates its application, especially in remote areas and low-income countries. For the first time, the current work presents a smartphone-based colorimetric POCT for BAC analysis in urine without interference from urine matrix. It depends on BAC reaction with naphthoquinone sulfonate (NQS) in highly alkaline aqueous medium. The developed color was captured in a customized photo box using smartphone camera. Then, intensity of the blue channel was measured by a software application "Color Analyzer". All parameters were optimized with respect to the colorimetric reaction, photographing and smartphone-based analysis. All parameters were successfully investigated according to FDA guidelines for bioanalytical method validation. Also, all POCT criteria were considered as per WHO requirements. This method could determine BAC, linearly, from 0.02 to 0.21 mmol L-1 in urine. Moreover, LLOQ was lower than the expected BAC therapeutic concentrations in urine. The proposed method proved high reliability and suitability to analyze BAC in urine. This strongly recommends its routine application in screening BAC abusers and BAC therapeutic monitoring.

Chitosan nanoparticles modified TLC-densitometry for determination of imidacloprid and deltamethrin residues in plants: greenness assessment.

Two thin layer chromatography (TLC) methods have been developed for the determination of pesticides residues of imidacloprid (IMD) and deltamethrin (DLM) in thyme and guava leaves. In the two methods, the used stationary phase was silica gel 60 F254 plates impregnated in chitosan nanoparticles (ChTNPs) 0.5% to improve separation using a green developing system consists of isopropyl alcohol for IMD and n-hexane-toluene-ethylacetate for DLM. The two pesticides were determined quantitatively, after TLC separation, at wavelengths 270.0 nm for IMD and 230.0 nm for DLM. Validation of both approaches was carried out in agreement with the guidelines of International Conference on Harmonization (ICH) and found to be selective, reliable and reproducible. Limits of detection of IMD and DLM were 0.002 and 0.00116 µg/spot, respectively. The newly developed TLC methods were used to monitor the pre-harvest interval estimation. Analytical eco-scaling depending on penalty points for IMD was calculated and showed that this method was eco-friendlier than the reported one.

Novel Spectrophotometric Approaches for the Simultaneous Quantification of Ternary Common Cold Mixture Containing Paracetamol with a Challenging Formulation Ratio: Greenness Profile Evaluation.

BACKGROUND: Common cold and cough preparations represent a huge segment of the global pharmaceutical market. Recently, cold/cough formulations containing paracetamol (PAR) have attracted significant attention as PAR has been implemented into the supportive treatment of mild cases of COVID-19 as the first-line antipyretic. From a literature review, no method has been reported yet for simultaneous estimation of PAR, pseudoephedrine hydrochloride (PSE) and carbinoxamine maleate (CRX) in any matrix. Thus, there is an urgent need for smart and green methods that would enable quantification of the cited components in their challenging ratio. OBJECTIVES: The aim of this work is to develop and validate the first UV spectrophotometric methods for simultaneous determination of the selected drugs taking into consideration the list of challenges including the highly overlapping features and spectral interferences in the cited mixture. METHODS: Namely, the proposed methods are: direct spectrophotometry, dual wavelength, first derivative, derivative ratio, ratio difference, constant center coupled with spectrum subtraction, and the constant multiplication method paired with spectrum subtraction. RESULTS: These methods were linear over the concentration range of 2.5-35, 1.5-20, and 4.5-35 µg/mL for PAR, PSE and CRX, respectively. These methods fulfill the validity parameters according to International Conference on Harmonization (ICH) guidelines. The results obtained were statistically benchmarked to the official ones where no significant difference was noticed. CONCLUSION: The developed methods are successfully applied for concurrent quantification of the studied components in the marketed dosage form without interference from matrix excipients. The impact on the environment was assessed by five green metrics, namely a recent Analytical greenness (AGREE) metric algorithm based on the green analytical chemistry framework, Green Analytical Procedure Index (GAPI), Eco-Scale, Assessment of Green Profile (AGP), and National Environmental Methods Index (NEMI). HIGHLIGHTS: Eco-friendly and successive spectrophotometric methods were firstly developed in this work, for the simultaneous quantification of PAR, PSE and CRX. These approaches incorporate a simple enrichment-aided technique to augment their spectrophotometric signals, facilitating the accurate quantitation of the minor component in the cited mixture.

Appraisal for Edible Use of Vegetable Crops Cultivated in Egypt after Treatment with Selected Insecticides and Fungicides: Insights of Dissipation Rates and Pre-harvest Intervals.

An analytical investigation was carried out to study the dissipation rate of two commonly used pesticides, thiamethoxam (neonicotinoid insecticide) and propamocarb hydrochloride (carbamate fungicide), applied to four vegetable crops: cucumber, zucchini, lettuce and pepper, after open-field application. Samples were harvested according to a scheduled plan followed by QuEChERS extraction, then thiamethoxam residues were analyzed using a GC-ECD method, while propamocarb HCl residues were analyzed using an HPLC-UV method. Validation parameters were attained for both methods and the kinetic profile was studied, which fitted the first-order kinetics where k, t1/2 and t90 were calculated. The proper pre-harvest interval (PHI) was studied for each crop to ensure that the residues levels declined to reach below the maximum residue limit (MRL) where the crop is suitable for consumption. These values were found to be different from labelled values, which proves that the PHIs are greatly affected by changing weather conditions.

When is it safe to eat different broiler chicken tissues after administration of doxycycline and tylosin mixture?

Residues of veterinary drugs in poultry meat have serious health effects on humans (e.g., antimicrobial resistance, carcinogenicity, and hypersensitivity), which make the control of veterinary drug residues an important parameter in ensuring consumer protection.  This work was performed to quantitatively determine two co-formulated anti-infective veterinary agents, tylosin tartrate (TYT) and doxycycline hydrochloride (DOX) in different tissues of broiler chickens (liver, muscles, and fat) using high performance liquid chromatography. The chicken was treated with the recommended dose of a binary mixture of the drugs (Tydovet). Moreover, the study aimed to estimate the withdrawal time of both drugs in chicken tissues. The analysis was done by solvent extraction and solid-phase extraction for clean-up of samples from the tissue matrix, followed by liquid chromatographic determination of the cited drugs with UV-detection. Residue decline with time was tracked, and both antibiotics were found to be more persistent in liver tissues than other tissues (muscle and fat). The effect of freezing and cooking was investigated on tissue residue levels. While freezing had little effect on the concentration of both antibiotics; cooking, as anticipated, led to a marked decline. Therefore, it is recommended to pay attention to the proper withdrawal periods before marketing to ensure the hygienic suitability of broilers edibles for safe human consumption. PRACTICAL APPLICATION: This novel study measures tylosin and doxycycline residues simultaneously in different tissues (muscle, fat, and liver) after administration of Tydovet powder to the broiler chicken. Residues in fat persisted for a longer time than in muscle in case of TYT, whereas the reverse was noticed in DOX.

A Thorough HPLC Assay of Quaternary Veterinary Formulation coupled with Environmental Assessment Tool.

A new and accurate reversed phase HPLC method with UV detection has been established for any veterinarian analyst for simultaneous determination of a veterinary quaternary mixture of sulphadimidine sodium (SDS), sulphaquinoxaline sodium (SQS), diaveridine (DVD) and vitamin K3 (VTK3) in their formulation. The stationary phase was SEA C18 column (250 × 4.6 mm i.d., 5 µm particle size) at 25°C with an isocratic mode, using a mobile phase containing a mixture of methanol:acetonitrile:distilled water in the ratio of (20:20:60, by volume). The flow rate was 0.8 mL min-1, and UV detection was performed at 230 nm. The HPLC assay was coupled with Environmental Assessment Tool (EAT), which represents a simple and proficient approach for profiling the greenness of the method. This takes into consideration the environmental, health and safety issues for all solvents that involved in the chromatographic method and calculates a total score that can be used for comparison of the greenness of different methods. The method was found to be linear over (0.5-30) µg/mL for all cited drugs with mean percentage recoveries (99.56 ± 1.141) for VTK3, (99.56 ± 1.056) for DVD, (99.62 ± 1.482) for SDS and (99.52 ± 1.205) for SQS. The results were statistically compared with those of the official and reported methods; using Student's t-test and F-test, showing no significant difference with respect to accuracy. Specificity of the applied method was assessed by analyzing the laboratory-prepared mixtures. The developed method was validated according to ICH guidelines. The proposed methodology can be applied for rapid routine assay of this combination.

FTIR combined with chemometric tools (fingerprinting spectroscopy) in comparison to HPLC: which strategy offers more opportunities as a green analytical chemistry technique for pharmaceutical analysis.

Fourier transform infrared spectroscopy (FTIR) is a widespread technique that can provide a chemical signature (fingerprints) of solid, liquid, or gas samples with a wide range of analytical applications. High-performance liquid chromatography (HPLC) is a leading analytical strategy for pharmaceutical analysis. Here we present a side-by-side comparison of the potential of these techniques for quantitative analysis of pharmaceutical active ingredient combinations in light of green analytical chemistry (GAC) principles. The methods were successfully applied for the analysis of ketoprofen (KTP)/hyoscine (HYS) and benzocaine (BENZ)/dextromethorphan HBr (DEX) in their binary mixtures and pharmaceutical preparations. In FTIR analysis, calibration models were constructed based on partial least squares regression (PLSR) with satisfactory regression coefficients (r2) of 0.9998, 0.9994, 0.9855, and 0.9895 for KTP, HYS, DEX, and BENZ, respectively, over a wide linearity range (10-100, 10-100, 5-75, and 10-100 µg mL-1) that covers the concentration ratios in the market samples. External validation using a validation set and internal validation using leave-one-out-cross-validation calculations were performed, and small root-mean-square-error-of-cross-validation (RMSECV) values were obtained indicating the good resolving power of the models. The same performance was obtained using the HPLC method for separation of the same mixtures with r2 equal to 0.9998, 0.9999, 0.9998, and 0.9998 over linear ranges of 50-1000, 10-200, 5-100, and 5-100 µg mL-1 for KTP, HYS, DEX, and BENZ, respectively. The HPLC methods were validated following ICH guidelines with good recovery percentages in the range of 98-100%. The statistical comparison of the FTIR and HPLC methods for analysis showed almost the same results with good applicability towards commercial dosage forms. Concerning the twelve GAC principles, a detailed comparison was performed to highlight the opportunities of each technique. FTIR-PLSR analysis showed superior performance as it allows for less solvent consumption, portability, less generated waste, short operating time, less operation cost, less energy consumption, and more operator safety and it is easily coupled with chemometric tools. Besides, FTIR is a direct analytical technique that can be used for the analysis of samples in all the physical forms (solid, liquid, and gas) without modifications.

Impact Study of Mathematical Manipulation on the Resolution Efficiency of the Spectrophotometric Technique-An Application on Veterinary Binary Mixture with Overlapping Absorption Bands.

BACKGROUND: The impact of mathematical manipulation on the efficiency of smart spectrophotometric approaches was considered for analyzing a veterinary binary mixture of tylosin tartrate (TYT) and doxycycline hydrochloride (DOX). OBJECTIVE: Based on subtraction which can be response subtraction via numerical factor calculation between two wavelengths. METHOD: Absorbance subtraction (AS) and amplitude summation (A-Sum), or subtraction of constant value or spectrum, was used to eliminate the contribution of the interfering component, as is done in spectrum subtraction (SS), extended ratio subtraction (EXRS), ratio subtraction (RS), and derivative subtraction (DS), or multiplication of a constant value by the divisor to get the spectrum of one component, or division by the normalized spectrum to modulate the original absorption spectrum to concentration as in concentration value and also detected in amplitude modulation (AM). The derivative transformation method (DT) is a form of mathematical manipulation that transforms a derivative to its original absorption form. RESULTS: The consumption of these methods will become more significant in quality control departments for the repetitive quantitative analysis of different veterinary products in both research and industry laboratories. Some manipulations may be used for simultaneous analysis of DOX and TYT, such as absorbance subtraction, amplitude modulation, ratio subtraction and derivative subtraction coupled with spectrum subtraction, concentration value, and amplitude summation, while others may be used for DOX only, such as derivative transformation and constant value. CONCLUSIONS: The recovery percentages confirmed that the accuracy and the reproducibility were approved by the following ICH guidelines. HIGHLIGHTS: 1. Partitioning methods: which perfectly divide the drugs response at the iso-point such as amplitude modulation, absorbance subtraction and amplitude summation. 2. Extracting methods: which easily calculate zero-order of the two cited drugs in such as ratio subtraction were coupled with extended ratio subtraction method (RS-EXRS), spectrum subtraction (SS), constant multiplication method (CM) or extract their derivative spectra such as derivative subtraction. 3. Transforming methods: which able to change the derivatized spectrum to its original zero spectra such as derivative transformation. 4. Graphical methods: which directly measure the concentration of the drugs from the chart.

Comprehensive comparative study of eco-friendly Univariate and multivariate methodological approaches on processing multi-component formulation quality.

This study presents comprehensive comparative study of different eco-friendly spectrophotometric approaches without any sample treatment on processing quaternary mixture of sulphadimidine sodium (SDS), sulphaquinoxaline sodium (SQS), diaveridine (DVD) and vitamin K3 (VTK3). The different univariate complementary resolutions according to the response used for the assay of the cited drugs after applying the processing steps were implemented using successive ratio subtraction coupled with constant multiplication (SRS-CM), absorbance subtraction (AS) and amplitude modulation (AM). On the other hand, multivariate spectrophotometric models were developed and validated for simultaneous determination of the cited mixture. Resolution was accomplished by using two multivariate calibration greener models, including principal component regression (PCR) and partial least-squares (PLS). The proposed approaches are considered environmentally friendly since they use only water as reagent, which is cheap and safe for the operator. The calibration graphs are linear over the range of (4.0-13.0) µg/mL for (SDS), (1.0-10.0) µg/mL for (SQS), (1.0-11.0) µg/mL for (DVD) and (1.0-8.0) µg/mL for (VTK3). Specificity of the applied procedures was assessed by analyzing the laboratory-prepared mixtures and their combined dosage form. The outcomes of the developed methods were statistically compared with those of the official and reported methods; using Student's t-test and F-test, showing no significant difference. The proposed methodologies can be used for the routine analysis of the cited drugs in quality control laboratories.

Novel feature extraction approach for achieving potential spectral resolution: Green analytical application on zofenopril calcium and hydrochlorothiazide in their spectrally overlapping binary mixture.

A novel and green spectrophotometric method, namely constant extraction, based on extracting a spectral feature value (constant ratio) has been developed and validated for simultaneous estimation of a binary mixture of zofenopril calcium (ZOF) and hydrochlorothiazide (HCT) in their bulk and marketable formulation. A comparative study between this newly developed method and four long-established ones; ratio difference, ratio subtraction coupled with constant multiplication, advanced amplitude modulation and absorbance subtraction has been carried out giving very promising results. Various analytical performance parameters like linearity, accuracy, precision, and robustness were investigated in accordance with ICH (Q2B). Satisfying optimized instrumental parameters; absorbance of ZOF and HCT were linearly increased for the previously mentioned methods in a concentration range 5.0-35.0 and 3.0-20.0 µg/mL, respectively showing correlation coefficients ≥0.9990. Moreover, specificity has been checked through analyzing synthetic mixtures of the studied analytes. Feasibility has been successfully assessed by simultaneous quantification of both analytes in the commercially available formulation. As well, validity was examined and no interference from common excipients was noticed. Observed data has been statistically compared with those of the published one concluding that no significant variations between both results have been indicated. Furthermore, greenness profile of these methods was assessed by analytical Eco-Scale and found superior to that of the reported HPLC method as an even greener approach for the simultaneous analysis of ZOF and HCT.

Spectrophotometric assessment of the brand new antiviral combination: Sofosbuvir and velpatasvir in their pure forms and pharmaceutical formulation.

Sofosbuvir (SOF) and velpatasvir (VEL) are recently co-formulated together for the treatment of hepatitis C virus. Smart and robust spectrophotometric methods were first developed and validated for quantification of SOF and VEL in their pure forms and in their combined pharmaceutical formulation without preliminary separation. VEL has two UV maxima at 302.5 and 337.0 nm that allow its direct determination by zero-order spectrophotometric method (D°) without any interference from SOF in a linear range of 2.0-30.0 µg/mL. On the other hand, determination of SOF in presence of VEL was carried out by four smart spectrophotometric methods, developed for resolving the overlaid spectra of these binary mixture. These methods are dual wavelength (DW), ratio subtraction (RS), ratio difference (RD) and first derivative of ratio spectra method (1DD). Linearity was checked and found to be in the range of 5.0-90.0 µg/mL for SOF by all of the aforementioned spectrophotometric methods. The developed methods were optimized and validated in accordance to the ICH guidelines. They were successfully utilized for estimating both SOF and VEL in their pure forms, laboratory prepared mixtures and in their pharmaceutical formulations with good recoveries. The methods can be easily applied for the routine analysis in quality control laboratories.

An Umeclidinium membrane sensor; Two-step optimization strategy for improved responses.

In the scientific context of membrane sensors and improved experimentation, we devised an experimentally designed protocol for sensor optimization. Two-step strategy was implemented for Umeclidinium bromide (UMEC) analysis which is a novel quinuclidine-based muscarinic antagonist used for maintenance treatment of symptoms accompanied with chronic obstructive pulmonary disease. In the first place, membrane components were screened for ideal ion exchanger, ionophore and plasticizer using three categorical factors at three levels in Taguchi design. Secondly, experimentally designed optimization was followed in order to tune the sensor up for finest responses. Twelve experiments were randomly carried out in a continuous factor design. Nernstian response, detection limit and selectivity were assigned as responses in these designs. The optimized membrane sensor contained tetrakis-[3,5-bis(trifluoro- methyl)phenyl] borate (0.44wt%) and calix[6]arene (0.43wt%) in 50.00% PVC plasticized with 49.13wt% 2-ni-tro-phenyl octylether. This sensor, along with an optimum concentration of inner filling solution (2×10-4molL-1 UMEC) and 2h of soaking time, attained the design objectives. Nernstian response approached 59.7mV/decade and detection limit decreased by about two order of magnitude (8×10-8mol L-1) through this optimization protocol. The proposed sensor was validated for UMEC determination in its linear range (3.16×10-7 -1×10-3mol L-1) and challenged for selective discrimination of other congeners and inorganic cations. Results of INCRUSE ELLIPTA® inhalation powder analyses obtained from the proposed sensor and manufacturer's UPLC were statistically compared. Moreover the proposed sensor was successfully used for the determination of UMEC in plasma samples.

Simultaneous Determination of Cinnarizine and Dimenhydrinate in Binary Mixture Using Chromatographic Methods.

Two accurate and sensitive chromatographic methods have been developed and validated for simultaneous determination of cinnarizine (CIN) and dimenhydrinate (DIM). The first method uses simultaneous quantitative thin layer chromatography (TLC) spectrodensitometric evaluation of them, using ethyl acetate:methylene chloride (8 : 2 by volume) as a mobile phase. Chromatograms are scanned at 254 nm. This method analyzes CIN in a concentration range of 0.5-6 µg per band with mean percentage recovery of 99.78 ± 1.001 and DIM in a concentration range of 1-6 µg per band with mean percentage recovery of 99.87 ± 1.319. The second method is high-performance liquid chromatography using methanol:acetonitrile:water [85 : 10 : 5, by volume +0.5% tri ethyl amine (TEA)] as a mobile phase. The linearity was found to be in the range of 10-60 and 5-60 µg mL(-1) for CIN and DIM, respectively. The methods were successfully applied to the simultaneous determination of CIN and DIM in bulk powder, laboratory-prepared mixtures and pharmaceutical dosage forms. The validity of results was assessed by applying standard addition techniques. The results obtained are found to agree statistically with those obtained by a reported method, showing no significant difference with respect to accuracy and precision.

Determination of tetraconazole and diniconazole fungicide residues in tomatoes and green beans by capillary gas chromatography.

A sensitive gas chromatographic method using an electron-capture detector (ECD) has been developed for the determination of tetraconazole and diniconazole fungicide residues in tomatoes and green beans. The developed method consists of extraction with methanol, partition with methylene chloride, and column chromatographic clean-up, followed by capillary gas chromatographic determination. The recoveries of both fungicides were greater than 90% for both plant samples. The limits of determination of the method were 0.001 ppm for both fungicides. The method was applied to determine residues and the rate of disappearance of tetraconazole and diniconazole from tomatoes and green beans [open field treatment, 50 cc of Domark 10% EC (emulsifiable concentrate), and 35 cc of Sumi-eight 5% EC; both for 100 l of water]. The fungicides incorporated into the plants decreased rapidly with a half-life around 3 days for diniconazole and from 4.5 to 6.5 days for tetraconazole. No residues could be detected in the plants during the period of study of 21 days after field application. Hence, the plants could be used safely after that period of time.