Development and validation of a precise flow injection method for the assessment of brexpiprazole, with application to pharmaceutical dosage forms and human plasma analysis.

A novel antipsychotic medication named brexpiprazole (BRX) is currently employed for the treatment of schizophrenia and other psychotic disorders. Because BRX's molecular structure includes a benzothiophene ring, it natively fluoresces. To detect BRX with precision and speed, a flow injection-fluorometric method, which is both sensitive and selective, is recommended. The fluorescence detection was conducted at 364 nm following excitation at 326 nm to capture the strong intrinsic fluorescence of BRX. The carrier solution employed was a mixture of phosphate buffer (pH 4, 10 mM) and acetonitrile (50: 50, v/v), with a flow rate of 0.5 mL min- 1. The calibration curve, based on peak areas, exhibited linearity within the concentration range of 20-350 ng mL- 1, with a remarkable correlation coefficient (r2) of 0.9999. The limit of quantitation was 9.7 ng mL- 1, and the limit of detection was found to be 3.2 ng mL- 1. This method was applied to quantify BRX in Neopression® tablets, achieving recovery within an acceptable range without interference from the tablet's additives. Additionally, the proposed approach was successfully utilised to quantify the drug in spiked human plasma. The approach underwent validation following ICH requirements.

Unified calibration of D-dimer can improve the uniformity of different detection systems.

Background: D-dimer at a low level is important evidence for excluding the onset and progression of thrombosis. It is readily detectable and yields rapid results, although significant variability exists among different detection systems. Our study aims to enhance the consistency across various detection systems. Methods: Twelve detection systems were included in our study. We sought to address this inconsistency by using various calibrators (two supplied by manufacturers and two comprising pooled human plasma diluted with different diluents) to standardize D-dimer measurements. We categorized the data into three groups according to D-dimer concentration levels: low (≤0.5 mg/L), medium (>0.5 mg/L - <3 mg/L), and high (≥3 mg/L). We then analyzed the data focusing on range, consistency, comparability, negative coincidence rate, and false negative rate. Results: Calibrating with pooled human plasma led to narrower result ranges in the low and medium groups (P < 0.05). In the low group, consistency improved from weak to strong (ICC 0.4-0.7, P﹤0.05), while it remained excellent in the other groups and overall (ICCï¹¥0.75, P﹤0.05). The percentage of pairwise comparability increased in both the low and high groups. Additionally, there was an increase in the negative coincidence rate. Conclusion: These findings demonstrate that uniform calibration of D-dimer can significantly enhance the consistency of results across different detection systems.

Design, Characterization and Biopharmaceutical Applications of Novel Green Boron-Carbon Quantum Dots for Quantification of Apalutamide; Greenness Evaluations.

The diagnosis of prostate cancer has been evolving in the current decade, with expected mortality rates of 499,000 death by the year 2030. Apalutamide (APL) has been approved in 2018 as the first drug for the controlling of prostate cancer. APL significant success warrantied its high global sales, which are expected to surpass 58% of segment market sales (together with another drug; enzalutamide). Therefore, new, fast and environmentally friendly analytical methods are required for its determination for the quality control and biological monitoring purposes. The proposed research designs and evaluates the first fluorimetric approach based on novel porous green boron-doped carbon quantum dots (B@CDs) for the determination of APL in biopharmaceutical matrices. The synthetic approach has high quantum yield (31.15%). B@CDs were characterized using several tools, including transmission electron microscopy (TEM), dynamic light scattering (DLS), FTIR and Energy dispersive X-ray spectroscopy (EDX) which proved their improved surface properties with an average nano-diameter of 3.0 nm. The interaction between B@CDs and APL led to enhancement their fluorescence at 441 nm (excitation at 372 nm). The approach was validated for the determination of APL within concentration range of 15.0-700.0 ng mL- 1 with quantification limit LOQ 4.37 ng mL- 1 and detection limit LOD 1.44 ng mL- 1. The approach was successfully applied for the determination of APL in human plasma and pharmaceutical monitoring of its marketed tablet form. Then, the approach was assessed for its environmental impact using different metrics and proved its ecological greenness.

Cell-free hemoglobin and hemin catalyzing triclosan oxidative coupling in plasma: A novel exogenous phenolic pollutants coupling pathway.

Previous studies reported that hemoprotein CYP450 catalyzed triclosan coupling is an "uncommon" metabolic pathway that may enhance toxicity, raising concerns about its environmental and health impacts. Hemoglobin, a notable hemoprotein, can catalyze endogenous phenolic amino acid tyrosine coupling reactions. Our study explored the feasibility of these coupling reactions for exogenous phenolic pollutants in plasma. Both hemoglobin and hemin were found to catalyze triclosan coupling in the presence of H2O2. This resulted in the formation of five diTCS-2 H, two diTCS-Cl-3 H, and twelve triTCS-4 H in phosphate buffer, with a total of nineteen triclosan coupling products monitored using LC-QTOF. In plasma, five diTCS-2 H, two diTCS-Cl-3 H, and two triTCS-4 H were detected in hemoglobin-catalyzed reactions. Hemin showed a weaker catalytic effect on triclosan transformation compared to hemoglobin, likely due to hemin dimerization and oxidative degradation by H2O2, which limits its catalytic efficiency. Triclosan transformation in the human plasma-like medium still occurs with high H2O2, despite the presence of antioxidant proteins that typically inhibit such transformations. In plasma, free H2O2 was depleted within 40 minutes when 800 µM H2O2 was added, suggesting a rapid consumption of H2O2 in these reactions. Antioxidative species, or hemoglobin/hemin scavengers such as bovine serum albumin, may inhibit but not completely terminate the triclosan coupling reactions. Previous studies reported that diTCS-2 H showed higher hydrophobicity and greater endocrine-disrupting effects compared to triclosan, which further underscores the potential health risks. This study indicates that hemoglobin and heme in human plasma might significantly contribute to phenolic coupling reactions, potentially increasing health risks.

Assessment of remdesivir and its nucleoside metabolite in beagle dogs and healthy humans by liquid chromatography coupled with triple quadrupole mass spectrometry.

The aim of this study was to assess the pharmacokinetics of the existing remdesivir intravenous formulation (100 mg dose) against the newly developed oral formulation (20 mg dose) for remdesivir and its active nucleoside metabolite (GS-441524) in beagle dogs followed by healthy human volunteers. A quantification method for remdesivir and its active nucleoside metabolite (GS-441524) in beagle dog and human plasma has been developed and validated using liquid chromatography coupled to triple quadrupole mass spectrometry detection. The analytical methods for beagle dogs and human differ in the calibration curve range, plasma matrix, processing volume, reconstitution volume and injection volume; however all other parameters were same in both methods. A simple protein precipitation extraction was carried out using acetonitrile containing the internal standard remdesivir D5. Remdesivir and GS-441524 were separated on an Endurus C-18P, 100 × 4.6 mm, 3 µm column and detected using a mass spectrometer with electrospray ionization in positive ion mode. The ion transitions used were m/z 603.1 → m/z 200.0 for remdesivir, m/z 292.0 → m/z 202.2 for GS-441524 and m/z 608.2 → m/z 205.1 for remdesivir D5. The calibration curve results were linear in beagle dog plasma (2.0-2,000.8 ng/ml range for remdesivir and 2.0-1,500.4 ng/ml for GS-441524) and human plasma (30.0-4,503.9 ng/ml range for remdesivir and 2.0-200.4 ng/ml for GS-441524). The recovery was >90% in beagle dog and human plasma. These methods were successfully used to determine the pharmacokinetic parameters of the intravenous injection and subcutaneous tablets dosage forms in beagle dogs and healthy humans.

Improved method for quantification of intact oxaliplatin by ultra high performance liquid chromatography-inductively coupled plasma mass spectrometry: Applications to clinical and speciation studies.

Interest is increasing in the use of different liquid chromatography techniques coupled online to mass spectrometry for the quantification of platinum anticancer drugs in human plasma to inform cancer chemotherapy. We developed, validated and studied the application of a method for quantification of intact oxaliplatin in human plasma using ultra high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (UHPLC-ICP-MS). Plasma samples were processed instantly after collection from patients to preserve oxaliplatin speciation by methanol-deproteinization, and storage of diluted supernatants (plasma:methanol 1:2 v/v) at -80 °C. UHPLC separation of intact oxaliplatin and internal standard (carboplatin) was achieved using a C18 column and linear gradient mobile phase (Mobile phase A: water-methanol (97:3 v/v), 0.075 mM sodium dodecyl sulfate, 9.79 nM thallium adjusted to pH 2.5 with trifluoromethanesulfonic acid; Mobile phase B: 100 % methanol (v/v)) with ICP-MS detection to monitor platinum and thallium at m/z 195 and 205, respectively. The limit of quantification was 50 nM in methanol-deproteinized diluted plasma (1:2 v/v). Linearity was established for calibration standards ranging from 50 to 500 nM made in methanol-deproteinized diluted plasma (1:2 v/v), and for dilution of higher concentration samples in blank matrix containing internal standard (final dilution 1:29 v/v). Intra-day and inter-day accuracy ranged from 96.8 to 103 % of nominal concentration and precision from 0.62 to 2.49 % coefficient of variation. Recovery was complete and a matrix effect confirmed the requirement for matrix-matched standards. Intact oxaliplatin was stable during storage for at least 473 days, and during analysis, in methanol-deproteinized diluted plasma (1:2 v/v). The method was applied to determining the plasma concentrations of intact oxaliplatin in patients undergoing cancer chemotherapy, and studies of oxaliplatin degradation in vitro. This improved method based on UHPLC-ICP-MS will allow more specific, efficient and reliable quantification of intact oxaliplatin in human plasma.

A highly sensitive spectrofluorimetric method for the determination of bilastine in human plasma: Application of content uniformity testing.

Bilastine, a new second generation antihistaminic drug, has been widely used for relieving symptoms of allergic rhinitis and urticaria without a sedative effect. A simple, cost-effective, and highly sensitive fluorimetric method was developed for the estimation of bilastine in human plasma, in addition to its pure state and tablets. The suggested method depended on binary complex formation of eosin with bilastine in a buffered medium at pH 4.2. The formed complex resulted in quantitative quenching of eosin emission at 538 nm after excitation at 335 nm. This method demonstrates a broad range of linearity, spanning from 200 to 1000 ng/mL, and exhibits exceptional sensitivity, with a limit of detection and quantitation of 30.85 and 93.48 ng/mL, respectively. In addition, this spectrofluorimetric method may be employed to determine the amount of bilastine in human plasma and tablets with satisfactory accuracy and excellent precision. Furthermore, the content uniformity of bilastine in commercially available tablets was successfully tested by this approach. Compared with the reference method, there were no significant variations in terms of precision or accuracy. In conclusion, the proposed protocol is highly recommended to quantitatively estimate bilastine in different quality control settings.

Development of UPLC-MS/MS method for the simultaneous quantification of valproic acid and phenytoin in human plasma and application to study pharmacokinetic interaction in epilepsy patients.

Valproic acid and phenytoin are two prevalent antiepileptic medications known for their narrow indices and propensity for cardiovascular and respiratory system toxicity. Therefore, therapeutic drug monitoring (TDM) of valproic acid (VAL) and phenytoin (PHE) concentrations in patient plasma is extremely beneficial for improving clinical choices, avoiding adverse reactions, and optimizing treatment for individual patients. In this study, a rapid and sensitive ultra-performance liquid chromatographic tandem mass spectrometer (UPLC-MS/MS) method was developed and validated for the simultaneous quantitative determination of valproic acid (VAL) and phenytoin (PHE) in human plasma. Negative electron spray ionization (ESI-) mode with selective ion recording (SIR) was employed to determine the transitions of m/z 142.98 and m/z 250.93 for VAL and PHE, respectively. The internal standard (IS) betamethasone (BETA) was ionized using positive electron spray ionization (ESI+) and detected by multi-reaction monitoring (MRM) mode to obtain precursor ions and specific fragment ions for quantification, and the MRM transition was chosen to be m/z 393.17 â†’ 355.16. The separation was performed using a Phenomenex Synergi Hydro-RP (4 µm, 250 × 4.6 mm, I.D.) with an isocratic mobile phase consisting of acetonitrile - water (75:25, v/v) at a flow rate of 0.8 mL/min. The column temperature was maintained at 25 °C. The lower limit of quantification of VAL and PHE was 3.6 µg/mL and 0.72 µg/mL, respectively, which resulted in a recovery of more than 85 % for most analytes. According to US-FDA bioanalytical technique validation, the specificity, intra- and inter-day precision and accuracy, matrix effect, carryover, dilution, and stability of all analytes were within acceptable ranges. This analytical method was successful in evaluating the levels of valproic acid and phenytoin in human plasma from epileptic patients.

Novel electrospun-based extractive probes for rapid determination of clinically important compounds in human plasma.

BACKGROUND: Coated blade spray (CBS) represents an innovative approach that utilizes solid-phase microextraction principles for sampling and sample preparation. When combined with ambient mass spectrometry (MS), it can also serve as an electrospray ionization source. Therefore, it became a promising tool in analytical applications as it can significantly reduce the analysis time. However, the current CBS coatings are based on the immobilization of extractive particles in bulk polymeric glue, which constrains the diffusion of the analytes to reach the extractive phase; therefore, the full reward of the system cannot be taken at pre-equilibrium. This has sparked the notion of developing new CBS probes that exhibit enhanced kinetics. RESULTS: With this aim, to generate a new extractive phase with improved extraction kinetics, poly(divinylbenzene) (PDVB) nanoparticles were synthesized by mini-emulsion polymerization and then immobilized into sub-micrometer (in diameter) sized polyacrylonitrile fibers which were obtained by electrospinning method. Following the optimization and characterization studies, the electrospun-coated blades were used to determine cholesterol, testosterone, and progesterone in plasma spots using the CBS-MS approach. For testosterone and progesterone, 10 ng mL-1 limits of quantification could be obtained, which was 200 ng mL-1 for cholesterol in spot-sized samples without including any pre-treatment steps to samples prior to extraction. SIGNIFICANCE: The comparison of the initial kinetics for dip-coated and electrospun-coated CBS probes proved that the electrospinning process could enhance the extraction kinetics; therefore, it can be used for more sensitive analyses. The total analysis time with this method, from sample preparation to instrumental analysis, takes only 7 min, which suggests that the new probes are promising for fast diagnostic applications.

Quantification and analyses of seven tyrosine kinase inhibitors targeting hepatocellular carcinoma in human plasma by QuEChERS and UPLC-MS/MS.

Tyrosine kinase inhibitors (TKIs) are commonly used to treat various cancers. Literature suggests that the blood concentration of TKIs strongly correlates with their efficacy and adverse effects. Therefore, establishing a Therapeutic Drug Monitoring (TDM) methodology for TKI drugs is crucial to improving their clinical efficacy and minimizing the treatment-related adverse effects. However, quantifying their concentrations in the plasma using existing methods to avoid potential toxicity is challenging. Herein, seven TKIs, namely sorafenib tosylate, axitinib, erlotinib, cediranib, brivanib, linifanib, and golvatinib, were successfully analyzed in human plasma by following a quick, easy, cheap, effective, rugged, and safe (QuEChERS) pretreatment method combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Briefly, biological samples were extracted using 1 mL of methanol, followed by the sequential addition of 250 mg of anhydrous magnesium sulfate and 25 mg of N-propylethylenediamine (PSA) for salinization and purification by adsorption, respectively. In this study, dovitinib was used as the internal standard. The seven TKIs were detected by the gradient elution method for 4 min in the positive ion electrospray mode. The mobile phase comprised methanol (phase A) and 0.1 % aqueous formic acid solution (phase B) on the Agilent Zorbax RRHD Stablebond Aq, (2.1 × 50 mm; 1.8 µm). Brivanib, linifanib, axitinib, sorafenib tosylate, and golvatinib exhibited good linearity in the range of 5-500 ng/mL, and erlotinib and cediranib exhibited good linearity in the range of 10-1000 ng/mL, with linear correlation coefficients (R2) ≥ 0.99. The limits of detection and quantification were 0.60-0.18 ng/mL and 5-10 ng/mL, respectively. The intraday and interday accuracy values ranged from -6.12 % to 7.31 %, with a precision (RSD) of ≤ 10.57 %. The method was rapid, accurate, specific, simple, reproducible, and suitable for the quantitative determination of the seven TKIs in human plasma.

Microbial reduction of prebagged human plasma using 405 nm light and its effects on coagulation factors.

Bacterial contamination is the most prevalent infectious complication of blood transfusion in the developed world. To mitigate this, several ultraviolet light-based pathogen reduction technologies (PRTs), some of which require photo-chemicals, have been developed to minimize infection transmission. Relative to UV light, visible 405-nm light is safer and has shown potential to be developed as a PRT for the in situ treatment of ex vivo human plasma and platelet concentrates, without the need for photo-chemicals. This study investigates the effect of 405-nm light on human plasma, with focus on the compatibility of antimicrobial light doses with essential plasma clotting factors. To determine an effective antimicrobial dose that is compatible with plasma, prebagged human plasma (up to 300 mL) was seeded with common microbial contaminants and treated with increasing doses of 405-nm light (16 mW cm-2; ≤ 403 J cm-2). Post-exposure plasma protein integrity was investigated using an AOPP assay, in vitro coagulation tests, and ELISA-based measurement of fibrinogen and Protein S. Microbial contamination in 300 mL prebagged human plasma was significantly reduced (P ≤ 0.05) after exposure to ≤ 288 J cm-2, with microbial loads reduced by > 96.2%. This dose did not significantly affect the plasma protein quality parameters tested (P > 0.05). Increased doses (≥ 345 J cm-2) resulted in a 4.3% increase in clot times with no statistically significant change in protein activity or levels. Overall, this study has demonstrated that the effective microbicidal 405 light dose shows little to no negative effect on plasma quality.

Whiteness and greenness assessments of a sensitive HPLC method with fluorimetric detection for dapagliflozin quantitation in human plasma: Application to a healthy human volunteer.

The evident ecological impact of human actions, like air pollution, global warming, and ozone depletion, underscores the need for environmentally friendly approaches across various domains, including analytical chemistry. This study aimed to establish a validated, eco-friendly, and sustainable approach utilizing a fluorescence detector coupled with high-performance liquid chromatography for quantifying the antihyperglycemic agent dapagliflozin (DAPA), in human plasma. This method employed a C18 Microsorb MV (4.5 × 250 mm, 5 µm [particle size]) column at 40°C, with 40:60% v/v isocratic elution of acetonitrile and (0.1%) orthophosphoric acid as the mobile phase at 1 mL/min flow rate. DAPA and the internal standard demonstrated their greatest response by performing excitation at 225 nm (λex) and recording chromatograms at an emission wavelength (λem) equal to 305 nm. The presented approach demonstrated high linearity between 50 and 2000 ng/mL and full adherence to the guidelines of the US Food and Drug Administration regarding the validation of bioanalytical methods. The described technique was effectively used for quantification of DAPA in human plasma samples from a healthy male participant who received a tablet of 10 mg DAPA. Analytical Eco-Scale, Analytical GREEnness metric, and the recently created ChlorTox Scale were utilized for greenness assessment. Additionally, the "Red, Green, and Blue 12" model was used in whiteness evaluation.

Validated LC/MS method for simultaneous determination of elbasvir and grazoprevir in human plasma.

A sensitive and accurate LC/MS method for the determination of elbasvir (ELB) and grazoprevir (GZP) in human plasma was established using daclatasvir (DCT) as an internal standard. The analytes were separated on a Waters Spherisorb phenyl column (150mm×4.6mm ID, 5µm particle size) maintained at 40°C±2°C. Gradient elution, at a flow rate of 0.8mLmin-1, was used. The mobile phase consists of 90% of acetonitrile mixed to 10% of a 5mM ammonium formate buffer (+0.1% v/v of trimethylamine, pH was adjusted to 3.2 by formic acid) as phase A and 10% of acetonitrile mixed to 90% of the same buffer as phase B. Liquid-liquid extraction with ethyl acetate solvent was used to recuperate compounds from plasma. The method was validated over a concentration range of 2 and 100ng/mL for GZP and between 1 and 50ng/mL for ELB. The intra- and inter-day precision and accuracy of the quality control samples at low, medium, and high concentration levels exhibited relative standard deviations (RSD)<15%, and the accuracy values ranged from 94.2 to 107.8%. The robustness of the method was established using a two-level full factorial design.

Anti-acetylated-tau immunotherapy is neuroprotective in tauopathy and brain injury.

BACKGROUND: Tau is aberrantly acetylated in various neurodegenerative conditions, including Alzheimer's disease, frontotemporal lobar degeneration (FTLD), and traumatic brain injury (TBI). Previously, we reported that reducing acetylated tau by pharmacologically inhibiting p300-mediated tau acetylation at lysine 174 reduces tau pathology and improves cognitive function in animal models. METHODS: We investigated the therapeutic efficacy of two different antibodies that specifically target acetylated lysine 174 on tau (ac-tauK174). We treated PS19 mice, which harbor the P301S tauopathy mutation that causes FTLD, with anti-ac-tauK174 and measured effects on tau pathology, neurodegeneration, and neurobehavioral outcomes. Furthermore, PS19 mice received treatment post-TBI to evaluate the ability of the immunotherapy to prevent TBI-induced exacerbation of tauopathy phenotypes. Ac-tauK174 measurements in human plasma following TBI were also collected to establish a link between trauma and acetylated tau levels, and single nuclei RNA-sequencing of post-TBI brain tissues from treated mice provided insights into the molecular mechanisms underlying the observed treatment effects. RESULTS: Anti-ac-tauK174 treatment mitigates neurobehavioral impairment and reduces tau pathology in PS19 mice. Ac-tauK174 increases significantly in human plasma 24 h after TBI, and anti-ac-tauK174 treatment of PS19 mice blocked TBI-induced neurodegeneration and preserved memory functions. Anti-ac-tauK174 treatment rescues alterations of microglial and oligodendrocyte transcriptomic states following TBI in PS19 mice. CONCLUSIONS: The ability of anti-ac-tauK174 treatment to rescue neurobehavioral impairment, reduce tau pathology, and rescue glial responses demonstrates that targeting tau acetylation at K174 is a promising neuroprotective therapeutic approach to human tauopathies resulting from TBI or genetic disease.

Turn-on fluorescence of mirabegron for its sensitive detection in human plasma: Box-Behnken-Design for optimization.

Here, a novel fluorescence strategy was established for the detection of mirabegron (MBG) sensitively on the basis of hantzsch dihydropyridine synthesis. The developed method adopts turn-on fluorescence of MBG for the first time, permitting its selective determination in spiked human plasma at 486 nm after excitation at 410 nm. The developed method exhibited a good linear range from 0.5 µgmL-1 to 2.0 µgmL-1 with detection and quantification limits of 0.05 and 0.2 (µgmL-1), respectively. The profitable applicability of the developed method in spiked human plasma samples was demonstrated, achieving limit of detection below the previously levels reported by spectroscopic methods, allowing application of the developed method for selective determination of MBG in its tablets and spiked human plasma samples with good recovery.

Analysis of 15 bile acids in human plasma based on C18 functionalized magnetic organic polymer nanocomposite coupled with liquid chromatography-tandem mass spectrometry.

Because of the "enterohepatic circulation" of bile acid, liver damage can be reflected by monitoring the content of bile acid in the serum of the organism. To monitor the concentration of 15 bile acids in plasma samples, a new technique of PRiME (process, ruggedness, improvement, matrix effect, ease of use) pass-through cleanup procedure combined with high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS/MS) was developed. The sorbent used in the PRiME pass-through cleanup procedure is a new type of magnetic organic resin composite nano-material modified by C18 (C18-PS-DVB-GMA-Fe3O4), which has high cleanup efficiency of plasma samples. It also shows good performance in the separation and analysis of 15 kinds of bile acids. Under the optimal conditions, the results show higher cleanup efficiency of C18-PS-DVB-GMA-Fe3O4 with recoveries in the range of 82.1-115 %. The limit of quantitative (LOQs) of 15 bile acids were in the range of 0.033 µg/L-0.19 µg/L, and the RSD values of 15 bile acids were in the range of 3.00-11.9 %. Validation results on linearity, specificity, accuracy and precision, as well as on the application to analysis of 15 bile acids in 100 human plasma samples demonstrate the applicability to clinical studies.

Fine-tuning Fluorescence of Amlodipine Adopting on Blocking of Photoinduced Electron Transfer (PET): Application in Human Plasma.

Assessing medication adherence through the determination of antihypertensive drugs in biological matrices holds significant importance. Amlodipine (AP), a potent antihypertensive medication extensively prescribed for hypertensive patients, is particularly noteworthy in this context. This article aims to introduce a rapid, simple, improved sensitivity, and reproducibility in detecting AP in its pure form, tablet formulation, and spiked human plasma than the other reported methods. The proposed method utilizes a fluorescence approach, relying on the inhibition of the intramolecular photoinduced electron transfer (PET) effect of the lone pair of the N-atom in the primary amino moiety of AP. This inhibition is achieved by acidifying the surrounding medium using 0.2 M acetic acid. By blocking PET, the target AP drug is sensitively detected, at [Formula: see text] 423 nm over a concentration range 25-500 ng mL- 1 showcasing an exceptionally low quantitation limit of 1.41 ng mL- 1. Notably, this innovative technique was successfully applied to detect AP in its solid dosage form and spiked human plasma. Remarkably, matrix interference was found to be insignificant, underscoring the robustness and applicability of the established approach. The combination of speed, sensitivity, and reproducibility makes this method particularly suitable for assessing medication adherence in patients prescribed AP for hypertension.

Simultaneous measurement of duloxetine hydrochloride and avanafil at dual-wavelength using novel ecologically friendly TLC-densitometric method: application to synthetic mixture and spiked human plasma with evaluation of greenness and blueness.

The simultaneous assay of duloxetine hydrochloride (DLX) and avanafil (AVN) in their pure forms, synthetic mixtures, and spiked human plasma was achieved using a novel, eco-friendly, sensitive, and specific HPTLC methodology that have been established and validated. Measuring the levels of co-administered antidepressants and sexual stimulants in biological fluids is an important step for individuals with depression and sexual problems. Separation was performed successfully using pre-coated silica gel 60-F254 as a stationary phase and a mobile phase composed of methanol, acetone, and 33% ammonia (8:2:0.05, v/v/v). Compact bands were produced by the optimized mobile phase that was chosen for development (Rf values were 0.23 and 0.75 for DLX and AVN, individually) after dual-wavelength detection for DLX and AVN at 232 and 253 nm, respectively. The results of polynomial regression analysis were exceptional (r = 0.9999 for both medicines) over concentration ranges of 5-800 and 10-800ng/spot for DLX and AVN, respectively. The quantitation limits were 4.69 and 9.53 ng/spot (0.31 and 0.94 µg/mL), whereas the detection limits were 1.55 and 3.15 ng/spot (0.63 and 1.91 µg/mL), for DLX and AVN, respectively. The International Council for Harmonization (ICH) criteria served as the basis for validating the established approach. Moreover, the proposed technique was evaluated in terms of greenness using four contemporary ecological metrics: The Analytical Greenness software (AGREE), the Green Analytical Procedure Index (GAPI), Eco-Scale, and the National Environmental Method Index (NEMI). Additionally, the Blue Applicability Grade Index (BAGI), a newly developed tool for evaluating the practicality (blueness) of procedures, was taken into consideration when evaluating the sustainability levels of the established approach.

Two chromatographic methods for determination of cytarabine and dexamethazone; two co-administered drugs for the treatment of leukemia: green analytical perspective.

Two sensitive, straightforward and repeatable chromatographic techniques were developed for the determination of Cytarabine HCl and Dexamethazone in their pure form and spiked human plasma without prior separation. The drugs are used co-administered for the treatment of Leukemia, a certain type of blood cancer. Method (A) is an isocratic chromatographic HPLC method; separation was accomplished on C18 column using the eluting mixture of 6.9 g/L Monobasic Sodium Phosphate pH 3: methanol (70:30, v/v) and detection was at 275 nm. Concentrations were in the range of 0.2-15 µg/mL for both CYT and DEX. Method (B) is a HPTLC method in which separation was attained on HPTLC F254 plates using methanol: ethyl acetate: ammonia, (7.8:2:0.2, by volume) as eluting solvents and detection was at 275 nm. Concentrations were in the range of 0.1-4 µg/band for both CYT and DEX. The parameters for system suitability testing were evaluated to determine the effectiveness of the developed chromatographic procedures in terms of performance. The recently developed techniques were applied for the determination of the drugs under investigation in spiked human plasma. Validation parameters were examined in accordance with US-FDA criteria. All results were found to be within the acceptable ranges. To evaluate the greenness characters of the proposed methods to the environment; three greenness assessment tools including eco-scale assessments (ESA), green analytical procedure index (GAPI), and Analytical Greenness calculator (AGREE) were used. Acceptable and satisfying results that demonstrated the greenness characteristics of the suggested methods were attained.

First DFT-supported point of care and novel electrochemical biosensing: Determination of yellow fever NS1 antibody in human plasma.

In our study, we developed a point of care electrochemical biosensing platform based on the functionalized cysteine-positioned gold electrode to diagnose yellow fever disease from human plasma samples. The developed platform underwent characterization through diverse methods encompassing cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and density-functional theory. The capacitive interaction between yellow fever virus non-structural antigen and antibody gave a cathodic signal at approximately -260 mV, and increased in proportion to the amount of non-structural antibody. The created electrochemical biosensor has an ability to detect 96 ag/mL of the yellow fever non-structural antibody with an extensive analytical range varied from 0.1 fg/mL to 1 µg/mL. The interference effects of various substances that could be found in human plasma, and the performance of the method were examined from the point of recovery and relative standard deviation for human plasma samples; hereby, the results confirmed the unprecedented selectivity and accuracy of the proposed method.