Pharmaceutical Analysis Research Articles

Green Analytical Chemistry to Eco-Friendly HPLC Techniques in Pharmaceutical Analysis: A Review

Green Analytical Chemistry to Eco-Friendly HPLC Techniques in Pharmaceutical Analysis: A Review

Powerful Analytical Platform for Diazepam Determination in Pharmaceuticals and Alcoholic Drink Based on Batch Injection Analysis Coupled with Adsorptive Stripping Voltammetry

Abstract The presented study focuses on the development and optimization of a powerful electroanalytical platform for the direct quantification of diazepam (DZP). This innovative approach integrates a batch injection analysis (BIA) system with a screen-printed electrode arrangement employing square-wave adsorptive stripping voltammetry (SWAdSV). The BIA-SWAdSV method underwent a comprehensive evaluation, wherein various experimental and instrumental parameters were systematically examined in detail. Beneficial analytical performance for detecting DZP was attained in Britton-Robinson buffer with pH 6.0, with an amplitude of 75 mV, a frequency of 10 Hz, a deposition potential of –1.2 V, a deposition time of 150 s, an injection volume of 75 µL, a dispensing rate of 7 µL/s, and without stirring during the deposition step. Under these conditions, the proposed BIA-SWAdSV method demonstrated an adequately broad linear concentration range from 5 to 40 µM (R2 = 0.997) with a micromolar limit of detection of (2 µM) and a satisfactory precision (RSD = 5%). The practical applicability of the newly-established and powerful analytical protocol was confirmed through the analysis of pharmaceuticals and a "fortified" sample of an alcoholic drink (rum) associated with potential criminal activities involving DZP abuse.

Electrochemical Sensors, Biosensors, and Optical Sensors for the Detection of Opioids and Their Analogs: Pharmaceutical, Clinical, and Forensic Applications

Pharmaceutical opioids are intravenously or orally administered analgesics. While they are effective in relieving chronic and acute pain, their narrow window of therapeutic use contributes to the high occurrence of abuse. The associated abuse of this family of drugs can be correlated to the increase in dependency, overdose, and death of users. The negative effects of opioids extend beyond the physical and psychological effects experienced by the user to their unregulated synthesis and sale, which contribute to socioeconomic challenges and are a biproduct of this global public health epidemic. From clinical to point-of-care applications, the detection and real-time monitoring of this family of drug is critical in the fight to decrease abuse and improve use in clinical settings. Chromatographic separations and chromatography–mass spectrometry are traditional methods of opioid analyses, but the high cost, long analysis time, and absence of portability highlight the need for the development of fast, in situ, point-of-care analysis, or of community drug monitoring services. This review highlights recent electrochemical and optical (FTIR, Raman, colorimetric, and fluorescent) advances and biosensors for pharmaceutical and illicit opioid analysis. Specifically, an emphasis is placed on the detection of opioids and their metabolites in biological samples and in vitro cellular assays for clinical diagnosis and forensic applications. The challenges and prospects of the role of electrochemical sensors, biosensors, and optical sensors for opioid analysis in promoting clinical diagnosis, forensic study, point-of-care, and community drug monitoring services to reduce harm are also provided.

Quality assessment of metformin hydrochloride tablets retailed in Lagos, Nigeria

Background: Metformin is a biguanide antihyperglycemic drug used with diet and exercise for glycemic control in type 2 diabetes mellitus.Objectives: This research aims to compare and analyze different metformin products to ascertain their critical quality parameters. The goal is to ensure that prescribed medicine effectively treats patients and protects the public.Materials and Methods: We evaluated the quality of ten metformin tablet brands in Lagos (Mushin and Surulere area) using official methods to assess weight, hardness, friability, disintegration time, and dissolution. Active ingredient content was also measured.Results: Out of all the tablets tested, only 10 % had weights outside of the official British Pharmacopoeia 2002 limits (not more than two tablets should deviate from ±5% and none of the tablets should deviate by ± I0). The hardness test was passed by all the tablets (A minimum hardness of 4 kgF is a pass), while 80 % passed the friability test (weight loss of ≤ 1 %w/w is a pass). Additionally, all film-coated tablets disintegrated within 30 minutes according to United States Pharmacopoeia/National Formulary 2003 (film-coated tablets disintegrate within 30 minutes). Ninety percent of the tablets passed the dissolution test (drug release within 60 minutes should be between 93 and 103 %) and 90 % of all brands examined passed the assay test for the active ingredient contents. The British Pharmacopoeia 2019 standard was used for the dissolution test.Conclusion: Routine pharmaceutical analysis is essential for the quality of pharmaceutical products and the safety of consumers.

Green chemometric-assisted UV-spectrophotometric methods for the determination of favipiravir, cefixime and moxifloxacin hydrochloride as an effective therapeutic combination for COVID-19; application in pharmaceutical form and spiked human plasma

As pharmaceutical analysis progresses towards environmental sustainability, there is a growing need to enhance the safety and health conditions for analysts. Consequently, the incorporation of chemometrics into environmentally friendly analytical methods represents a promising approach. Favipiravir, cefixime, and moxifloxacin hydrochloride have been currently used in COVID-19 treatment. In this study, we develop spectrophotometric methods depending on chemometric based models to measure the levels of favipiravir, cefixime, and moxifloxacin hydrochloride in pharmaceutical preparations and spiked human plasma. It is challenging to determine favipiravir, cefixime, and moxifloxacin simultaneously because of overlap in their UV absorption spectra. Two advanced chemometric models, partial least square (PLS) and genetic algorithm (GA), have been developed to provide better predictive abilities in spectrophotometric determination of the drugs under study. The described models were created using a five-level, three-factor experimental design. The outcomes of the models have been thoroughly assessed and interpreted, and a statistical comparison with recognized values has been taken into consideration. The analytical eco-scale and the green analytical procedure index (GAPI) evaluation methods were also utilized to determine how environmentally friendly the mentioned models were. The outcomes demonstrated how well the models described complied with the environmental requirements.

Synchronous spectrofluorimetry and chemometric modeling: A synergistic approach for analyzing simeprevir and daclatasvir, with application to pharmacokinetics evaluation

Simeprevir and daclatasvir represent a cornerstone in the management of Hepatitis C Virus infection, a global health concern that affects millions of people worldwide. In this study, we propose a synergistic approach combining synchronous spectrofluorimetry and chemometric modeling i.e. Partial Least Squares (PLS-1) for the analysis of simeprevir and daclatasvir in different matrices. Moreover, the study employs firefly algorithms to further optimize the chemometric models via selecting the most informative features thus improving the accuracy and robustness of the calibration models. The firefly algorithm was able to reduce the number of selected wavelengths to 47–44% for simeprevir and daclatasvir, respectively offering a fast and sensitive technique for the determination of simeprevir and daclatasvir. Validation results underscore the models' effectiveness, as evidenced by recovery rates close to 100% with relative root mean square error of prediction (RRMSEP) of 2.253 and 2.1381 for simeprevir and daclatasvir, respectively. Moreover, the proposed models have been applied to determine the pharmacokinetics of simeprevir and daclatasvir, providing valuable insights into their distribution and elimination patterns. Overall, the study demonstrates the effectiveness of synchronous spectrofluorimetry coupled with multivariate calibration optimized by firefly algorithms in accurately determining and quantifying simeprevir and daclatasvir in HCV antiviral treatment, offering potential applications in pharmaceutical formulation analysis and pharmacokinetic studies for these drugs.

Review on method development and validation for different pharmaceutical dosage form

Pharmaceutical analysis is crucial for bulk and formulation quality control. Due to global medication manufacturing and pharmaceutical sector expansion, innovative analytical methods are in demand. Developing analytical procedures is now the most significant part of analysis. Improvements in analytical instruments have led to new analytical methods. The improvement of analytical methodologies and technologies has reduced analysis time, increased precision and accuracy, and decreased analysis costs. As a consequence, the majority of pharmaceutical businesses are investing heavily in specialist analysis labs. Analytical techniques for active pharmaceutical ingredients (API), excipients, drug products, degradation products and related substances, residual solvents, and other chemicals are created and verified. As a consequence, it has become an essential component of the regulating organization's standards. Development of analytical methodologies leads to official test methods. Quality control labs utilize these methods to verify drug identity, purity, safety, effectiveness, and performance. Production analytical methods are becoming relevant to regulators. Regulatory agencies expect applicants to demonstrate control of the drug development process using established analytical methodologies.

UHPLC-MS/MS Technique: Applications in Analytical Chemistry

The ultra-high performance liquid chromatography-mass spectrometry/mass spectrometry (UHPLC-MS/MS) is becoming most advanced technique used for analysis of wide range of compounds in analytical chemistry. This technique has been effectively utilized for identifying and quantitatively determining substances in several pharmaceutical analysis fields. The UHPLC technique offers superior sensitivity, selectivity and peak shape in comparison to the conventional HPLC technique. The UHPLC coupled with various mass spectrometers gives accurate mass fragmentations which is ultimately helpful in structural identification and quantitative determination of compounds. The review provides brief introduction on development of UHPLC column packing materials and coupled mass detectors such as single quadrupole, triple quadrupole and time-of-flight mass. This review article also summarizes application of UHPLC-MS/MS technique in various fields of analytical chemistry.

Deep eutectic solvents as green and sustainable diluents in headspace gas chromatography for the determination of trace level genotoxic impurities in pharmaceuticals

Genotoxic impurities (GTIs) are potential carcinogens that need to be controlled down to ppm or lower concentration levels in pharmaceuticals under strict regulations. The static headspace gas chromatography (HS-GC) coupled with electron capture detection (ECD) is an effective approach to monitor halogenated and nitroaromatic genotoxins. Deep eutectic solvents (DESs) possess tunable physico-chemical properties and low vapor pressure for HS-GC methods. In this study, zwitterionic and non-ionic DESs have been used for the first time to develop and validate a sensitive analytical method for the analysis of 24 genotoxins at sub-ppm concentrations. Compared to non-ionic diluents, zwitterionic DESs produced exceptional analytical performance and the betaine : 7 (1,4- butane diol) DES outperformed the betaine : 5 (1,4-butane diol) DES. Limits of detection (LOD) down to the 5-ppb concentration level were achieved in DESs. Wide linear ranges spanning over 5 orders of magnitude (0.005–100 µg g−1) were obtained for most analytes with exceptional sensitivities and high precision. The method accuracy and precision were validated using 3 commercially available drug substances and excellent recoveries were obtained. This study broadens the applicability of HS-GC in the determination of less volatile GTIs by establishing DESs as viable diluent substitutes for organic solvents in routine pharmaceutical analysis.

Green spectrophotometric and spectrofluorimetric determination of biperiden hydrochloride using erythrosine B sensing probe.

Erythrosine B (EB) is a food colorant antiviral xanthene dye that has many applications as a color additive in pharmaceuticals and cosmetics. Its use as a sensor for spectrofluorimetric and spectrophotometric analysis of amine-based pharmaceuticals renders many advantages because of its availability, low cost, rapid labeling, and high sensitivity. Herein, two fast and sensitive spectrofluorimetric and spectrophotometric methods were established for the estimation of the anti-Parkinson drug, biperiden (BIP) hydrochloride (HCl), in its raw material and tablet forms. The proposed methods depended on the interaction between the phenolic group of EB and the tertiary amino group of the studied analyte to form an ion-pair complex at pH4 using the Britton Robinson buffer. The spectrofluorimetric method is based on the measurement of the quenching power of BIP HCl on the fluorescence intensity of EB at λex/em= 527.0/550.9nm. This method was rectilinear over the concentration range of 0.1-1.0μg/mL with a limit of detection (LOD) = 0.017 μg/mL and a limit of quantification (LOQ) = 0.05 μg/mL. Meanwhile, the colorimetric method involved monitoring the absorbance of the formed ion-pair complex at 555 nm, showing a linearity range of 0.4-5.0μg/mL with LOD = 0.106 μg/mL and LOQ = 0.322 μg/mL. The proposed methods were assessed for the greenness, indicating the greenness of the developed methods.

Electrochemical Detection of Nitrofurantoin using Green Synthesized Silver-doped Palladium Nanocluster-Modified Sensor

Aim:: This study presents a novel green synthesis approach for successfully fabricating silver-doped palladium nanoclusters (Ag-Pd NCs) using the aqueous leaf extract of Strobilanthes kunthiana as a reducing and stabilizing agent. Background:: The environmentally benign method offers a sustainable alternative to conventional chemical synthesis, circumventing hazardous chemicals and minimizing the generation of toxic byproducts. Objectives:: The successful green synthesis of Ag-Pd NCs using Strobilanthes kunthiana leaf extract and their application as an efficient electrochemical sensing platform for determining nitrofurantoin (NFT). Methods:: The synthesized Ag-Pd NCs were extensively characterized by using diverse analytical techniques, including UV-Vis spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and cyclic voltammetry (CV). Results:: As-synthesized Ag-Pd NCs were employed as a sensing platform for electrochemical detection of NFT, an important antibiotic widely used in clinical applications. The electrochemical method demonstrated a remarkable sensitivity of about 1.56 μA μM−1 cm−2, the lowest detection limit (LOD) of 3.2 μM and a linear range of determination from 5 to 210 μM. This new electrochemical sensor exhibited excellent stability and reproducibility, making it suitable for practical applications in real-world samples. Conclusions:: The green synthesis of Ag-Pd NCs using Strobilanthes kunthiana leaf extract and their application as an efficient electrochemical sensing platform for detecting NFT was demonstrated. The combination of green synthesis and advanced electrochemical sensing underscores the potential of these nanomaterials in developing environmentally friendly sensors for pharmaceutical analysis and clinical diagnostics. The findings presented herein will contribute to the growing field of green nanotechnology and sustainable sensor development for advanced healthcare and environmental monitoring.

Fabrication of a novel HKUST-1/CoFe2O4/g-C3N4 electrode for the electrochemical detection of ciprofloxacin in physiological samples

In this work, a novel HKUST-1/CoFe2O4/g-C3N4 electrode was successfully prepared via the hydrothermal method and the high-temperature calcination method, which can be applied as an electrochemical sensor for the precise detection of ciprofloxacin (CIP) in physiological samples. The novel electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR), and its electrochemical performance was further evaluated via the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The results demonstrated that the HKUST-1/CoFe2O4/g-C3N4 electrode exhibited an optimal linear range of 0.05–180 μmol L−1 for the CIP detection, which demonstrated a low limit of detection (LOD) of 0.0026 μmol L−1 and a low limit of quantitation (LOQ) of 0.0087 μmol L−1, respectively. Additionally, the novel semiconductor sensors exhibited exceptional selectivity, stability and repeatability in the determination of CIP. The recovery rate of CIP was found to range from 98.00% to 104.00% in serum, with the relative standard deviations (RSD) below 2.62% (n = 5), while the recovery rate of CIP was found to range from 96.00% to 105.00%, with the RSD less than 3.23% (n = 5) in urine. The current study extends to the application of the semiconductor-based electrochemical sensors and offers a new approach for the clinical pharmaceutical analysis to ensure medication safety, which could provide valuable insights into the potential of semiconductor sensors for future clinical applications.

Unique biomedical application of fluorescence derivatization based on palladium-catalyzed coupling reactions for HPLC analysis of pharmaceuticals and biomolecules.

Palladium-catalyzed coupling reactions are versatile and powerful tools for the construction of carbon-carbon bonds in organic synthesis. Although these reactions have favorable features that proceed selectively in mild reaction conditions using aqueous organic solvents, no attention has been given to their application in the field of biomedical analysis. Therefore, we focused on these reactions and evaluated the scope and limitations of their analytical performance. In this review, we describe the pros and cons and future trends of fluorescence derivatization of pharmaceuticals and biomolecules based on palladium-catalyzed coupling reactions such as Suzuki-Miyaura coupling, Mizoroki-Heck coupling, and Sonogashira coupling reactions for HPLC analysis.

Molecularly imprinted electrochemical sensor based on carbon nanofibers for Amiodarone determination

Amiodarone, a drug associated with significant cardiac, pulmonary, hepatic, and neurological complications, requires accurate measurement due to its narrow therapeutic window. However, the current analysis methods are time-consuming, complex, and expensive. Thus, there is a pressing need to develop a cost-effective and rapid solution for Amiodarone determination. In this study, a molecularly imprinted electrochemical sensor was designed, fabricated, and evaluated to detect Amiodarone precisely. The research involved the synthesis of magnetic nanoparticles coated with silica and the subsequent synthesis of a molecularly imprinted polymer. Carbon nanofibers were then prepared through electrospinning in a polyacrylonitrile furnace, onto which the molecularly imprinted polymer was placed. Multiple concentrations of Amiodarone were successfully determined utilizing this sensor. Following optimization, the designed sensor exhibited desirable traits such as linearity, reproducibility, precision, and accuracy. The sensor detection and quantification limit proved acceptable in whole blood and plasma samples. With its remarkable reproducibility and accurate detection of low concentrations, this molecularly imprinted electrochemical sensor offers a reliable method for quantifying Amiodarone in real samples. Moreover, its swift voltammetric response outperforms existing techniques regarding time efficiency. Overall, the developed sensor presents a valuable advancement and has the potential to benefit pharmaceutical analysis and clinical applications greatly.

Comprehensive Review on Chiral Stationary Phases in Single-Column Simultaneous Chiral-Achiral HPLC Separation Methods.

This comprehensive review explores the utilization of chiral stationary phases (CSPs) in the context of single-column simultaneous chiral-achiral high-performance liquid chromatography (HPLC) separation methods. While CSPs have traditionally been pivotal for enantioselective drug analysis, contemporary CSPs often exhibit notable chemoselective properties. Consequently, there is a discernible trend towards the development of methodologies that enable simultaneous enantio- and chemoselective separations utilizing a single CSP-based chromatographic column. This review provides an exhaustive overview of reported HPLC methods in this domain, with a focus on four major CSP types: cyclodextrin-, glycopeptide antibiotic-, protein-, and polysaccharide-based CSPs. This article delves into the diverse applications of CSPs, encompassing various chromatographic modes such as normal phase (NP), reverse phase (RP), and polar organic (PO). This review critically discusses method development, emphasizing the additional chemoselective separation mechanisms of CSPs. It also explores possibilities for method optimization and development, concluding with future perspectives on this evolving field. Despite the inherent challenges in understanding the retention mechanisms involved in chemoselective separations, this review highlights promising trends and anticipates a growing number of simultaneous enantio- and chemoselective methods in pharmaceutical analyses, pharmacokinetic studies, and environmental sample determinations.

Four chemometric models enhanced by Latin hypercube sampling design for quantification of anti-COVID drugs: sustainability profiling through multiple greenness, carbon footprint, blueness, and whiteness metrics

Montelukast sodium (MLK) and Levocetirizine dihydrochloride (LCZ) are widely prescribed medications with promising therapeutic potential against COVID-19. However, existing analytical methods for their quantification are unsustainable, relying on toxic solvents and expensive instrumentation. Herein, we pioneer a green, cost-effective chemometrics approach for MLK and LCZ analysis using UV spectroscopy and intelligent multivariate calibration. Following a multilevel multifactor experimental design, UV spectral data was acquired for 25 synthetic mixtures and modeled via classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), and genetic algorithm-PLS (GA-PLS) techniques. Latin hypercube sampling (LHS) strategically constructed an optimal validation set of 13 mixtures for unbiased predictive performance assessment. Following optimization of the models regarding latent variables (LVs) and wavelength region, the optimum root mean square error of cross-validation (RMSECV) was attained at 2 LVs for the 210–400 nm spectral range (191 data points). The GA-PLS model demonstrated superb accuracy, with recovery percentages (R%) from 98 to 102% for both analytes, and root mean square error of calibration (RMSEC) and prediction (RMSEP) of (0.0943, 0.1872) and (0.1926, 0.1779) for MLK and LCZ, respectively, as well bias-corrected mean square error of prediction (BCMSEP) of -0.0029 and 0.0176, relative root mean square error of prediction (RRMSEP) reaching 0.7516 and 0.6585, and limits of detection (LOD) reaching 0.0813 and 0.2273 for MLK and LCZ respectively. Practical pharmaceutical sample analysis was successfully confirmed via standard additions. We further conducted pioneering multidimensional sustainability evaluations using state-of-the-art greenness, blueness, and whiteness tools. The method demonstrated favorable environmental metrics across all assessment tools. The obtained Green National Environmental Method Index (NEMI), and Complementary Green Analytical Procedure Index (ComplexGAPI) quadrants affirmed green analytical principles. Additionally, the method had a high Analytical Greenness Metric (AGREE) score (0.90) and a low carbon footprint (0.021), indicating environmental friendliness. We also applied blueness and whiteness assessments using the high Blue Applicability Grade Index (BAGI) and Red–Green–Blue 12 (RGB 12) algorithms. The high BAGI (90) and RGB 12 (90.8) scores confirmed the method's strong applicability, cost-effectiveness, and sustainability. This work puts forward an optimal, economically viable green chemistry paradigm for pharmaceutical quality control aligned with sustainable development goals.

A Selective Gas Chromatography–Tandem Mass Spectrometry Method for Quantitation of Ethylene and Diethylene Glycol in Paediatric Syrups

Ethylene Glycol (EG) and diethylene Glycol (DEG) are two contaminants known to cause various human health problems. These glycols might be present in drug syrups that are based on glycerol, sorbitol, or polyethylene glycol. In late 2022, several batches of cough, antipyretics, and antihistamine syrups were reported to contain toxic levels of EG and DEG in multiple countries; this incident concerned the World Health Organization (WHO). From an analytical perspective, several methods of glycols analysis in pharmaceuticals have been reported in the literature, with the majority being dedicated to raw material analysis. This study aims to develop a selective method capable of evaluating a wide range of paediatric syrups in order to assess the safety of commercially available paediatric syrups currently distributed in the local market. This research introduces a method for determining glycols utilizing gas chromatography-tandem mass spectrometry (GC–MS/MS), which offers significantly higher selectivity than conventional single quadrupole gas chromatography-mass spectrometry (GC–MS). The developed method meets the current International Council for Harmonisation (ICH) guidelines for validation. The absence of any interfering peaks in both the unspiked sample of promethazine syrup and the reference standard solutions proved the method's selectivity. Furthermore, 2,2,2-trichloroethanol was used as an internal standard, and a new GC–MS/MS method was developed to analyze it. The calibration curves for EG and DEG were linear within the selected concentration range of 1–10 μg/mL. The detection limit for both EG and DEG was 400 ng/mL, while the quantification limit was 1 μg/mL. Recovery values for both EG and DEG met the accuracy acceptance criterion. Thus, the developed method proved to be efficient and accurate for determining EG and DEG levels in suspected contaminated syrups.

White analytical insight for sensitive fluorescent determination of semaglutide and tirzepatide in pharmaceuticals and biological matrices

The present study is focused on the sensitive determination of newly FDA-approved glucagon-like-peptide agonists semaglutide (SEM) and tirzepatide (TIR). Direct, selective and label-free spectrofluorometric method was proposed and validated (according to ICH guidelines) for determination SEM and TIR in their pure form, newly approved pharmaceuticals and spiked human plasma. The developed method was based on measuring the native fluorescence of SEM and TIR in ethanol at 294.8 and 303 nm after being excited at 216 and 225 nm for SEM and TIR in order. The method sensibility allowed the quantification of both drugs in nano-scale up to 10 ng/mL. Several experimental variables including solvent type, surfactant, and pH were optimized after several attempts to get the best sensitivity for both drugs. The mean recovery percentage of SEM was compared and found in agreement with the reported method using student’s t-test and the variance ratio F-test. Additionally, the greenness and whiteness profiles for this approach were evaluated using the GAPI, AGREE, and RGB algorithm; the positive results supported its use as great candidates for successful implementation in quality control labs and the pharmaceutical analysis companies.

Development and Validation of a Viable and User-Friendly Spectrophotometric Analytical Method for Estimation of Assay of Formoterol and Beclomethasone in Metered Dose Inhaler Formulation

The primary aim of this research endeavor is to innovate a viable and user-friendly UV spectroscopic approach for quantifying formoterol and beclomethasone within metered dose inhalers (MDIs). These formulations, amalgamating Beclomethasone Dipropionate (BDP) and Formoterol Fumarate (FF), are extensively employed in managing bronchial asthma and chronic obstructive pulmonary diseases. Although analytical techniques already exist for assessing formoterol and beclomethasone in combination dry powder inhalers, this study concentrates on devising and validating a UV spectrophotometric method for simultaneously quantifying formoterol fumarate and Anhydrous Beclomethasone Dipropionate in Pressurized Metered Dose Inhalers (pMDIs). The estimation is performed at a wavelength of 240 nm for Beclomethasone Dipropionate and 216 nm for Formoterol Fumarate. Both drugs demonstrate satisfactory linearity within the concentration range of 10-30 μg/ml for BDP and 0.3 to 0.9 μg/ml for FF at wavelengths of 240 nm (r^2=0.999) and 216 nm (r^2=0.999), respectively. The Beer-Lambert law is adhered to within the concentration range of 10-30 μg/ml for BDP and 0.3-0.9 μg/ml for FF. The proposed methods are subjected to validation following ICH guidelines to assess accuracy, method precision, specificity, among other parameters. As a result, the proposed method can be effectively employed for the simultaneous determination of Beclomethasone Dipropionate and Formoterol Fumarate in routine analytical applications, offering a rapid and reliable solution for pharmaceutical analysis in the field.

Combination of large-volume sample stacking with polarity switching and micelle electrokinetic chromatography for the analysis of anion compounds in Yangxinshi tablets.

Yangxinshi tablet (YXST) is a traditional Chinese medicine preparation characterized by its high efficacy and safety for the treatment of cardiovascular diseases. Anionic compounds have been revealed as potential active components. However, there is currently limited research regarding its quality control. We aimed to establish a strategy for the simultaneous separation and determination of five key anionic compounds in YXST. A sensitive and efficient analytical method was developed and applied for the simultaneous separation and determination of five key compounds in YXST using large-volume sample stacking with polarity switching and micelle electrokinetic chromatography (LVSS-PS-MEKC) coupled with diode array detection. Crucial parameters, including sample volume, applied voltage, composition and pH of the running buffer, concentration of organic modifier, and switching time of the polarity, were systematically evaluated and optimized using a single variable method to enhance separation performance. Furthermore, the impact of cyclodextrin and sodium dodecyl sulfate as electrolyte modifiers was also investigated. Under the optimal conditions, baseline separation of the five compounds (daidzein, puerarin, glycyrrhiztinic acid, chlorogenic acid, and salvianolic acid B) was achieved within 20 min. In comparison to the conventional MEKC mode, the constructed LVSS-PS-MEKC method exhibited a more than sixfold increase in the enrichment factor. The method was validated in terms of linearity, precision, accuracy, 24 h stability, and recovery and successfully applied to analyze YXST samples. A sensitive strategy was developed for the simultaneous separation and determination of five key anionic components in YXST, offering a robust and efficient strategy for pharmaceutical analysis.