Quality-by-design ecofriendly potentiometric sensor for rapid monitoring of hydroxychloroquine purity in the presence of toxic impurities

Hydroxychloroquine (HCQ) is prescribed to treat malaria and certain autoimmune diseases. Recent studies questioned its efficiency in relieving COVID-19 symptoms and improving clinical outcomes. This work presents a quality-by-design approach to develop, optimize, and validate a potentiometric sensor for the selective analysis of HCQ in the presence of its toxic impurities (key starting materials), namely 4,7-Dichloroquinoline (DCQ) and hydroxynovaldiamine (HND). The study employed a custom experimental design of 16 sensors with different ion exchangers, plasticizers, and ionophores. We observed the Nernstian slopes, correlation coefficients, quantification limit, response time, and selectivity coefficient for DCQ and HND. The computer software constructed a prediction model for each response. The predicted responses strongly correlate to the experimental ones, indicating model fitness. The optimized sensor achieved 93.8% desirability. It proved a slope of 30.57 mV/decade, a correlation coefficient of 0.9931, a quantification limit of 1.07 × 10-6 M, a detection limit of 2.18 × 10-7 M, and a fast response of 6.5 s within the pH range of 2.5-8.5. The sensor was successfully used to determine HCQ purity in its raw material. The sensor represents a potential tool for rapid, sensitive, and selective monitoring of HCQ purity during industrial production from its starting materials.

Spectrophotometric resolution for quantitative analysis of aspirin and rivaroxaban combination therapy in biological fluids using simple and eco-friendly procedure

Patients diagnosed with symptomatic peripheral artery disease (PAD) in the lower extremities have a higher likelihood of suffering from major vascular events. Recently, FDA has approved the combination therapy of aspirin (ASP) and rivaroxaban (ROX) to reduce acute limb ischemia and other comorbidities in (PAD) patients. Zero order and ratio absorption spectra were employed in three simple and accurate spectrophotometric techniques (dual wavelength (DW), ratio difference (RD) and derivative ratio (1DD) for concurrent detection and quantification of ASP and ROX in their pure forms, lab synthetic mixtures and in biological fluid. Our approach involves careful parameter optimization, including solvent selection, sample volumes, and instrumental settings, to reduce the analysis environmental impact. The acquired recovery percentages of accuracy were within 98-102% for pure active pharmaceutical ingredients and 90-110% for pharmaceutical formulations and biological determinations. A comprehensive assessment was done to compare the three methods regarding their ease of use, linearity, sensitivity, conditions, and limitations. The specificity of the proposed methods was evaluated by analyzing the lab synthetic mixtures. The suggested spectrophotometric methods were validated in compliance with ICH guidelines to confirm the validity claims. Also, statistical analysis was done to compare the outcomes obtained from the suggested methods with those obtained from the official ones and they agreed with null hypothesis regarding accuracy and precision. Furthermore, a comprehensive assessment of the environmental sustainability of the developed method was carried out using the Analytical Greenness Calculator, AGREE algorithm. The selected drugs can be efficiently, safely and economically analyzed by the suggested methods in pharmaceutical and biological matrices with no pretreatment or preliminary separation steps and thereby increasing their greenness level.

A sustainable approach for the degradation kinetics study and stability assay of the SARS-CoV-2 oral antiviral drug Molnupiravir

Molnupiravir (MPV) is the first direct-acting oral antiviral drug that effectively decreases nasopharyngeal infections with SARS-CoV-2 virus. The stability of MPV was tested by subjecting the drug to various stress conditions. The drug is liable to oxidative, acidic, and alkaline degradation and showed significant stability against thermal degradation. Mass spectrometry identified the degradation products and guided suggestion of the degradation patterns. Interestingly, while inspecting the UV-absorption spectra, we observed no absorbance at 270 nm for the products of the three degradation pathways (c.f. intact MPV). Direct spectrophotometry seemed a solution that perfectly fit the purpose of the stability assay method in our case. It avoids sophisticated instrumentation and complex mathematical data manipulation. The method determined MPV accurately (100.32% ± 1.62) and selectively (99.49% ± 1.63) within the linear range of 1.50 × 10^-5-4.0 × 10^-4 M and down to a detection limit of 0.48 × 10^-5 M. The proposed method is simple and does not require any preliminary separation or derivatization steps. The procedure proved its validity as per the ICH recommendations. The specificity was assessed in the presence of up to 90% degradation products. The study evaluated the greenness profile of the proposed analytical procedure using the National Environmental Methods Index (NEMI), the Analytical Eco-Scale, and the Green Analytical Procedure Index (GAPI). The three metrics unanimously agreed that the developed procedure results in a greener profile than the reported method. The method investigated the degradation reactions' kinetics and evaluated the reaction order, rate constant, and half-life time for each degradation process.

Prevalence and Antimicrobial Susceptibility of Bovine Mycoplasma Species in Egypt

Simple Summary

Bovine Mycoplasma species, particularly antimicrobial resistant Mycoplasma bovis are important causes of bovine respiratory disease (BRD) in cattle, which causes major economic losses worldwide. Thus, the current study aimed to determine the prevalence and antimicrobial resistance profiles of bovine Mycoplasma spp. isolated from cattle’s respiratory tracts, in addition to evaluating the fluoroquinolone resistance in the recovered isolates using broth microdilution and conventional PCR techniques in Egypt. Our result showed that M. bovis was the most common spp. (61%), followed by M. bovirhinis (15%). In total, mycoplasma isolates were more prevalent among all examined lung tissues (38%), followed by nasal swabs (35%), tracheal tissues (28%), and tracheal swabs (27%). All the examined mycoplasma isolates (n = 76) were 100% susceptible to spectinomycin, tulathromycin, spiramycin, and tylosin, but high doxycycline and enrofloxacin minimum inhibitory concentrations (MICs) values were observed among 43.4% and 60.5% of the tested isolates, respectively. Three and two mycoplasma isolates with high enrofloxacin MICs were confirmed to be M. bovis and M. bovirhinis, respectively, by PCR assays. All molecularly confirmed mycoplasma isolates (n = 5) were positive for the gyrA gene (100%), meanwhile, three isolates (60%) were positive for the parC gene. In conclusion, understanding antimicrobial resistance mechanisms is a significant tool for the future development of genetic-based diagnostic techniques for the rapid detection of resistant mycoplasma strains.

Abstract

Among many bovine Mycoplasma species (spp.), Mycoplasma bovis is recognized as a significant causative agent of respiratory diseases in cattle. In recent years, resistant M. bovis isolates, especially to fluoroquinolones, have been reported globally as a result of the extensive usage of antimicrobials in the treatment of bovine pneumonia. Therefore, the aim of this study is to investigate the prevalence and antimicrobial susceptibility patterns of bovine Mycoplasma spp. isolated from the respiratory tracts of cattle in Egypt and to assess the fluoroquinolones resistance in the recovered mycoplasma isolates via broth microdilution and conventional PCR techniques. Conventional phenotypic methods identified 128 mycoplasma isolates (32%) from 400 different samples, with M. bovis being the predominant spp. (61%), followed by M. bovirhinis (15%). Of note, mycoplasma isolates were rarely isolated from total healthy lung tissues (7/55, 12.7%), but they were frequently isolated from pneumonic lungs (31/45, 68.9%). All the examined mycoplasma isolates (n = 76) were sensitive to tilmicosin, tylosin, tulathromycin, spiramycin, and spectinomycin (100% each), while 60.5% and 43.4% of the examined isolates had high minimum inhibitory concentration (MIC) values to enrofloxacin and doxycycline, respectively. Three and two mycoplasma isolates with high enrofloxacin MICs were confirmed to be M. bovis and M. bovirhinis, respectively, by PCR assays. All molecularly confirmed mycoplasma isolates (n = 5) were positive for the gyrA gene (100%); meanwhile, three isolates (60%) were positive for the parC gene. In conclusion, our findings revealed alarming resistance to enrofloxacin and doxycycline antibiotics; thus, antimicrobial usage must be restricted and molecular techniques can help in the rapid detection of the resistant strains.

Solventless Microextration Techniques for Pharmaceutical Analysis: The Greener Solution

Extensive efforts have been made in the last decades to simplify the holistic sample preparation process. The idea of maximizing the extraction efficiency along with the reduction of extraction time, minimization/elimination of hazardous solvents, and miniaturization of the extraction device, eliminating sample pre- and posttreatment steps and reducing the sample volume requirement is always the goal for an analyst as it ensures the method’s congruency with the green analytical chemistry (GAC) principles and steps toward sustainability. In this context, the microextraction techniques such as solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), microextraction by packed sorbent (MEPS), fabric phase sorptive extraction (FPSE), in-tube extraction dynamic headspace (ITEX-DHS), and PAL SPME Arrow are being very active areas of research. To help transition into wider applications, the new solventless microextraction techniques have to be commercialized, automated, and validated, and their operating principles to be anchored to theory. In this work, the benefits and drawbacks of the advanced microextraction techniques will be discussed and compared, together with their applicability to the analysis of pharmaceuticals in different matrices.

Development and Validation of a Reliable LC-MS/MS Method for Simultaneous Quantification of Hydrochlorothiazide in the Presence of Different Co-formulated Anti-hypertensive Medications in Biological Matrix

Background:

Thiazide diuretics are listed as one of the first-line antihypertensive treatment agents. Hydrochlorothiazide is mainly formulated with many antihypertensive agents as combined pill therapy.

Objective:

In this study, a new, simple, rapid and sensitive LC-MS/MS assay was developed, optimized and validated for the simultaneous quantification of commonly prescribed cardiovascular combined medications that are used for hypertension management, including Hydrochlorothiazide (HCT) in the presence of irbesartan (IRB), candesartan (CAN) and bisoprolol (BISO) in human plasma.

Methods:

RP-HPLC separation of analytes and internal standard (atorvastatin) was performed on Zorbax Eclipse XDB-C18 (4.6×50 mm 5-Micron) using acetonitrile: (0.05%) formic acid (80:20), as an eluting system with a run time of less than 5.0 min.

Results:

Validation was carried out according to FDA guidelines for bioanalytical method. The recoveries were higher than 84.30%, the accuracy was within 86.82–110.17 % and the RSD was below 10% for all the studied compounds.

Conclusions:

The suggested method is highly appropriate for routine assays of the studied combination therapy in view of the lower LLOQ, simple extraction process, and short run time. The method can be further investigated and used for pharmacokinetics studies of the studied different antihypertensive combinations.

Developing, optimizing, and assessing a green electrophoretic method for determination of benzbromarone and allopurinol with its active metabolite in biological and pharmaceutical matrices

A combination of allopurinol and benzbromarone is a common gout treatment protocol. A suboptimal response to allopurinol in patients is very common due to its pharmacokinetics variability. Moreover, the safe doses of benzbromarone is very crucial in patients with hepatic diseases. This raised the inquisitiveness to develop and optimize a capillary zone electrophoresis method for the determination of allopurinol and benzbromarone in their coformulation and in the presence of oxypurinol, the active metabolite of allopurinol, in biological and pharmaceutical matrices. The method greenness profile was assessed using green metric tools the "National Environmental Method Index," the "Analytical Eco-Scale," and the "Green Analytical Procedure Index" by which the method proved to be ecofriendly. The method was successfully applied for the analysis of the pharmaceutical preparation and urine samples spiked with both drugs and the active metabolite. The linearity range was 25.0-250.0 μg/mL for benzbromarone, 50.0-350.0 μg/mL for allopurinol, and 100.0-500.0 μg/mL for oxypurinol. The recoveries were 99.60 ± 0.67, 99.89 ± 0.98, and 98.71 ± 1.18% for benzbromarone, allopurinol, and oxypurinol, respectively. The analysis results indicate potential usefulness of capillary zone electrophoresis as a competitive and greener method of analysis in biological and quality control labs.

Analytical Eco-Scale for Assessing the Greenness of a Developed RP-HPLC Method Used for Simultaneous Analysis of Combined Antihypertensive Medications

In the past few decades the analytical community has been focused on eliminating or reducing the usage of hazardous chemicals and solvents, in different analytical methodologies, that have been ascertained to be extremely dangerous to human health and environment. In this context, environmentally friendly, green, or clean practices have been implemented in different research areas. This study presents a greener alternative of conventional RP-HPLC methods for the simultaneous determination and quantitative analysis of a pharmaceutical ternary mixture composed of telmisartan, hydrochlorothiazide, and amlodipine besylate, using an ecofriendly mobile phase and short run time with the least amount of waste production. This solvent-replacement approach was feasible without compromising method performance criteria, such as separation efficiency, peak symmetry, and chromatographic retention. The greenness profile of the proposed method was assessed and compared with reported conventional methods using the analytical Eco-Scale as an assessment tool. The proposed method was found to be greener in terms of usage of hazardous chemicals and solvents, energy consumption, and production of waste. The proposed method can be safely used for the routine analysis of the studied pharmaceutical ternary mixture with a minimal detrimental impact on human health and the environment.

Green approach using monolithic column for simultaneous determination of coformulated drugs

Green chemistry and sustainability is now entirely encompassed across the majority of pharmaceutical companies and research labs. Researchers' attention is careworn toward implementing the green analytical chemistry principles for more eco-friendly analytical methodologies. Solvents play a dominant role in determining the greenness of the analytical procedure. Using safer solvents, the greenness profile of the methodology could be increased remarkably. In this context, a green chromatographic method has been developed and validated for the simultaneous determination of phenylephrine, paracetamol, and guaifenesin in their ternary pharmaceutical mixture. The chromatographic separation was carried out using monolithic column and green solvents as mobile phase. The use of monolithic column allows efficient separation protocols at higher flow rates, which results in short time of analysis. Two-factor three-level experimental design was used to optimize the chromatographic conditions. The greenness profile of the proposed methodology was assessed using eco-scale as a green metrics and was found to be an excellent green method with regard to the usage and production of hazardous chemicals and solvents, energy consumption, and amount of produced waste. The proposed method improved the environmental impact without compromising the analytical performance criteria and could be used as a safer alternate for the routine analysis of the studied drugs.

Oestrogen receptors beta genotype in infertile Egyptian men with nonobstructive azoospermia

In a prospective study, the polymorphism of oestrogen receptor β gene was investigated in nonobstructive azoospermia patients. Ninety infertile patients with nonobstructive azoospermia diagnosed after two semen analysis, 2 weeks apart and negative testicular sperm extraction during intracytoplasmic sperm injection, and 60 fertile men as controls were enrolled in the study. Semen analysis, hormonal profile and allele-specific PCR reaction were performed to detect variants of the RsaI polymorphism of the oestrogen receptor β gene for all patients and controls. The mean patient's age was significantly lower than the mean age of the controls (P < 0.05). There was a significant increase in the mean serum levels of FSH, LH, free testosterone and E2 and significant decrease in total testosterone in patients than controls (P < 0.05). In the patients, the frequency of the homozygous GG, heterozygous AG and homozygous AA genotype was 83.3%, 14.3% and 3.3% respectively, whereas their frequencies in the controls were 95%, 5% and 0% respectively (odds ratio 3.8). There is no significant correlation between ERß polymorphisms and patient's age or pituitary and sex hormones (P > 0.05). Our findings suggested that in Egyptian population, genetic mutation in ERß is associated with the risk of nonobstructive azoospermia.

Application and validation of superior spectrophotometric methods for simultaneous determination of ternary mixture used for hypertension management

Telmisartan (TL), Hydrochlorothiazide (HZ) and Amlodipine besylate (AM) are co-formulated together for hypertension management. Three smart, specific and precise spectrophotometric methods were applied and validated for simultaneous determination of the three cited drugs. Method A is the ratio isoabsorptive point and ratio difference in subtracted spectra (RIDSS) which is based on dividing the ternary mixture of the studied drugs by the spectrum of AM to get the division spectrum, from which concentration of AM can be obtained by measuring the amplitude values in the plateau region at 360nm. Then the amplitude value of the plateau region was subtracted from the division spectrum and HZ concentration was obtained by measuring the difference in amplitude values at 278.5 and 306nm (corresponding to zero difference of TL) while the total concentration of HZ and TL in the mixture was measured at their isoabsorptive point in the division spectrum at 278.5nm (Aiso). TL concentration is then obtained by subtraction. Method B; double divisor ratio spectra derivative spectrophotometry (RS-DS) and method C; mean centering of ratio spectra (MCR) spectrophotometric methods. The proposed methods did not require any initial separation steps prior the analysis of the three drugs. A comparative study was done between the three methods regarding their; simplicity, sensitivity and limitations. Specificity was investigated by analyzing the synthetic mixtures containing different ratios of the three studied drugs and their tablets dosage form. Statistical comparison of the obtained results with those found by the official methods was done, differences were non-significant in regard to accuracy and precision. The three methods were validated in accordance with ICH guidelines and can be used for quality control laboratories for TL, HZ and AM.

Chemometrics resolution and quantification power evaluation: Application on pharmaceutical quaternary mixture of Paracetamol, Guaifenesin, Phenylephrine and p-aminophenol

Three advanced chemmometric-assisted spectrophotometric methods namely; Concentration Residuals Augmented Classical Least Squares (CRACLS), Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and Principal Component Analysis-Artificial Neural Networks (PCA-ANN) were developed, validated and benchmarked to PLS calibration; to resolve the severely overlapped spectra and simultaneously determine; Paracetamol (PAR), Guaifenesin (GUA) and Phenylephrine (PHE) in their ternary mixture and in presence of p-aminophenol (AP) the main degradation product and synthesis impurity of Paracetamol. The analytical performance of the proposed methods was described by percentage recoveries, root mean square error of calibration and standard error of prediction. The four multivariate calibration methods could be directly used without any preliminary separation step and successfully applied for pharmaceutical formulation analysis, showing no excipients' interference.

A study of selective spectrophotometric methods for simultaneous determination of Itopride hydrochloride and Rabeprazole sodium binary mixture: Resolving sever overlapping spectra

Itopride hydrochloride (IT) and Rabeprazole sodium (RB) are co-formulated together for the treatment of gastro-esophageal reflux disease. Three simple, specific and accurate spectrophotometric methods were applied and validated for simultaneous determination of Itopride hydrochloride (IT) and Rabeprazole sodium (RB) namely; constant center (CC), ratio difference (RD) and mean centering of ratio spectra (MCR) spectrophotometric methods. Linear correlations were obtained in range of 10-110μg/μL for Itopride hydrochloride and 4-44μg/mL for Rabeprazole sodium. No preliminary separation steps were required prior the analysis of the two drugs using the proposed methods. Specificity was investigated by analyzing the synthetic mixtures containing the two cited drugs and their capsules dosage form. The obtained results were statistically compared with those obtained by the reported method, no significant difference was obtained with respect to accuracy and precision. The three methods were validated in accordance with ICH guidelines and can be used for quality control laboratories for IT and RB.

Application and validation of an eco-friendly TLC-densitometric method for simultaneous determination of co-formulated antihypertensive agents

Application and validation of eco-friendly TLC-densitometric method for simultaneous determination of co-formulated antihypertensive agents.

FT-IR spectroscopic analyses of 4-hydroxy-1-methyl-3-[2-nitro-2-oxoacetyl-2(1H)quinolinone (HMNOQ)

In the present work, a combined experimental and theoretical study on molecular structure and vibrational frequencies of 4-hydroxy-1-methyl-3-[2-nitro-2-oxoacetyl-2(1H)quinolinone (HMNOQ) was reported. The FT-IR spectrum of HMNCQ is recorded in the solid phase. The equilibrium geometries, harmonic vibrational frequencies, thermo-chemical parameters, total dipole moment and HOMO-LUMO energies are calculated by density functional theory DFT/B3LYP utilizing 6-311G(d,p) basis set. Results showed that HMNOQ is highly recommended to be a promising structure for many applications in optoelectronic devices due to its high calculated dipole moment value (9 Debye) which indicates its high reactivity to interact with the surrounding molecules. The HOMO-LUMO energy gap of HMNOQ is 4 eV.

Miniaturized membrane sensors for potentiometric determination of metoprolol tartrate and hydrochlorothiazide

Four microsized graphite and platinum wire poly(vinyl chloride) matrix membrane electrodes responsive to some drugs affecting cardiovascular system, Metoprolol tartrate (MT) and Hydrochlorothiazide (HZ) were developed, described and characterized. These sensors were constructed by using (2-Hydroxypropyl)-β-cyclodextrin (2HP β-CD) as an ionophore which has a significant influence on increasing both membrane sensitivity and selectivity. The four sensors were fabricated in a polymeric matrix of carboxylated polyvinyl chloride (PVC-COOH) and dioctylphthalate (DOP) as a plasticizer, based on the interaction between the drugs and the dissociated COOH groups in the PVC-COOH. Fast and stable Nernstian responses of 1.0 × 10-6-1.0 × 10-2 M for MT (sensors 1 and 2) and of 1.0 × 10-7-1.0 × 10-3 M for HZ (sensors 3 and 4) over pH range 3.0-9.0 and 3.0-7.0 for the MT and HZ sensors respectively were obtained. Nernstian slopes of 56.2, 54.6, 19.0 and 20.8 mV/decade for electrodes 1-4 respectively were observed. The proposed method displayed useful analytical characteristics for the determination of MT and HZ in their pure powder forms with average recoveries of 99.11 ± 0.357, 99.21 ± 0.389, 100.08 ± 0.459 and 100.28 ± 0.438% for sensors 1-4 respectively. The lower limit of detection (LOD) were 5.5 × 10-6, 4.5 × 10-6, 4.8 × 10-8 and 5.0 × 10-8 M for sensors 1-4 respectively indicated high sensitivity. The four sensors displayed a good stability over a period of 6 weeks. The selectivity coefficients of the developed sensors indicated excellent selectivity. Results obtained by the four electrodes revealed the performance characteristics of these electrodes which evaluated according to IUPAC recommendations. The method was successively applied for the determination of MT and HZ in presence of each other, in presence of Salamide (SA), the main degradation product of HZ, in their pharmaceutical formulations and in human plasma samples. Statistical comparison between the results obtained by this method and those obtained by the official methods of the drugs was done and no significant difference was found.

Novel pyridazine derivatives: Synthesis and antimicrobial activity evaluation

A general method for the preparation of new hydrazones is reported. The 1-[4-(2-methoxybenzyl)-6-aryl pyridazin-3(2H)-ylidene] hydrazines or their tautomeric structures (1(a-d)) were condensed with different aldehydes, dialdehydes, ketones, alpha-dicarbonyl compounds and simple carbohydrates to afford the hydrazones and dihydrazones (2(a-d)), (3(a-d)), (4(a-d)), (5(a-d)), (6(d)), (7(c)), (8(a-d)), (9(a-d)), (10(a-d)), (11(a-d)), (12(a,c,d)), (13(a-d)), (14(a-d)), (15(a-d)), (16(a-d)) and (17(a-d)). The structures of all synthesized compounds were confirmed from microanalytical and spectral data. Some of the products were screened for their antimicrobial activity against Staphylococcus aureus and Streptococcus faecalis, Escherichia coli and Pseudomonas aeruginosa. The hydrazone derivative 15(d) (1-[4-(2-methoxybenzyl)-6-methylphenyl pyridazin-3(2H)-ylidene]-2-(2-carboxydiphenyl methyl) hydrazine) showed the highest biological activity.