Eco-friendly Electrochemical Sensor for Quantification of Bumadizone in Pure, Pharmaceutical Dosage Form and in Spiked Human Plasma Using Pencil Graphite Electrode

Eco-friendly Electrochemical Sensor for Quantification of Bumadizone in Pure, Pharmaceutical Dosage Form and in Spiked Human Plasma Using Pencil Graphite Electrode | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Eco-friendly Electrochemical Sensor for Quantification of Bumadizone in Pure, Pharmaceutical Dosage Form and in Spiked Human Plasma Using Pencil Graphite Electrode Manal S. Elmasry, Israa M. Nour, Wafaa S. Hassan, Hanan A. Merey, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7112930/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Bumadizone calcium hemihydrate is a non-steroidal anti-inflammatory drug that is used to treat rheumatoid arthritis and post-traumatic edema through blocking prostaglandin synthesis. This work presents, for the first time, an electrochemical method has been developed for determination of bumadizone calcium hemihydrate in bulk, pharmaceutical dosage form and in spiked human plasma based on the oxidation nature of bumadiazone using pencil graphite electrode as a working electrode. The electrochemical oxidation of bumadizone at pencil graphite electrode surface in phosphate buffer pH 6.4 was investigated using cyclic and differential pulse voltammetry between -0.1 and 1.3 V against Ag/AgCl reference electrode. Experimental parameters of the suggested method as pH, scan rate, step potential, pulse amplitude and pulse width (modulation time) were well investigated and optimized. The proposed differential pulse voltametric method was found to be linear over the range 5.0×10 -7 to 5.0×10 -5 M with high correlation (r= 0.999). The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 1.6×10 -7 M, and 5.3×10 -7 M, respectively. Using pencil graphite electrode offers extra advantages to the proposed method of being widely commercially available, cost-effective, simple, disposable and mechanically rigid electrodes. The method was found to be efficiently applicable in spiked human plasma permitting bioequivalent or pharmacokinetic study in real human plasma samples. Greenness of the proposed method was evaluated using Eco-scale scoring tool revealing excellent greenness of the analytical method. Physical sciences/Chemistry Physical sciences/Materials science Differential pulse and cyclic voltammetry pencil graphite electrode spiked human plasma Eco-scale scoring tool Bumadiazone Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1. Introduction Rheumatoid arthritis (RA) is an autoimmune chronic inflammatory condition that affects about 0.5 to 1% of people worldwide and commonly cause joint deformity, damage and can finally leads to disability [ 1 ]. RA has a negative impacts on patient’s life quality regarding physical aspect (continual pain, stiffness or even disability), financial aspect (high-cost therapy) and social aspect (depression, dependency, impaired social relationship) [ 2 ]. Pain relieve is one of the main concerns of patients suffering from RA as persistent pain make them seek the medical therapy. Currently, drug management for RA includes symptomatic treatment with analgesics, non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying anti-rheumatic drugs (DMARDs). NSAIDs are cyclooxygenase isoforms inhibitors (COXs) that acts via reducing joint swelling and decreasing pain, but they cannot prevent progressive joint destruction [ 3 ]. Bumadizone calcium hemihydrate (BDZ) chemical structure is shown in Figure (1) is dicalcium; 2- [aniline (phenyl) carbamoyl] hexanoate; hydrate [ 4 ]. It is one of the NSAIDs that is used for to treat rheumatic disorders and post-traumatic edema through inhibition of cyclooxygenase by blocking the synthesis of prostaglandins [ 5 ]. Literature reviews reports that there is a few analytical techniques for quantitative determination of BDZ either alone or in presence of its alkaline degradation including spectrophotometric [ 6 , 7 ], Fourier transform-infrared [ 8 ], fluorometric [ 9 ] and chromatographic methods [ 10 , 11 ]. Interestingly, none of the reported methods were reported for the electrochemical estimation of BDZ. Compared to the reported methods, electrochemical methods have advantages of being simple, highly sensitive, low cost, easy to be applied and rapid compared to the reported methods which are time consuming, expensive and having complex procedures. Voltammetric sensors have been widely employed for the electroanalytical quantitative analysis of various analytes including drugs, environmental pollutants, and biomarkers. The sensors are based on measuring the current peak height produced as a function of applied voltage at working electrode (versus a reference electrode) [ 12 ]. The choice of suitable working electrode should be carefully planned to achieve maximum sensitivity and reproducibility of the analysis. Different voltammetric electrode substrates have been reported include carbon past electrode, mercury film electrode, gold electrode, glassy carbon electrode, platinum electrode among others [ 13 ]. Each type of electrode has its unique sensitivity and detection limit. There is an emerging interest for utilizing pencil graphite electrodes (PGEs) as substrates for the fabrication of electrochemical sensors, this can attributed to the advantages of PGEs such as: commercial availability, disposable, high conductance, high sensitivity, diminished background current, PGE surfaces can be easily modified with metals nanoparticles, polymers, and other nanoparticles. Many reviews have been published to highlight the recent progress of using PGEs in various fields including pharmaceutical, medicinal, environmental, etc. In this work, simple and sensitive cyclic voltammetric (CV) method has been used to study the oxidation behaviour of BDZ, and differential pulse voltammetry was developed for quantification of BDZ in pure, pharmaceutical dosage form and in spiked human plasma using pencil graphite electrode (PGE) surface. Pencil graphite sensor was used without any modification which provides improved advantages such as being widely available, cheap electrode, simple in application, disposable, highly selective and sensitive with low detection limit. 2. Experimental 2.1. Material and reagents: BDZ standard was kindly gifted by October Pharma company, Cairo, Egypt (with certified purity 99.86%). Octomotol® tablets, contain 110 mg of Bumadizone calcium hemihydrate (Bumadizone) as labeled, (batch no. B-02140317), October Pharma company, Cairo, Egypt, purchased from local market. Analytical grade solvents as ortho-phosphoric acid, sodium hydroxide, di-potassium hydrogen phosphate and acetonitrile were used (Sigma-Aldrich, Darmstadt, Germany). Britton–Robinson buffer (BRB) solutions (pH 2.0–9.0) were prepared by mixing a solution of (0.04 M phosphoric acid, 0.04 M glacial acetic acid and 0.04 M boric acid) and the appropriate pH value was adjusted by adding the necessary amount of 0.2 M NaOH solution. Water used was bi-distilled. Human plasma was brought from the Holding Company for Biological Products and Vaccines (VACSERA, Egypt). 2.2. Apparatus All voltametric determinations were done using a Metrohm Autolab potentiostat/ galvanostat PGSTAT204 electrochemical workstation. The electrochemical cell was PC-controlled and coupled with NOVA 1.11 software for electrochemistry. Ag/AgCl electrode was used as reference electrode, while the used counter electrode was a Pt wire. PGE (Tombow Ultra-Polymer, 2B, Japan) with 0.9 mm diameter and 60 mm of total length was used as the working electrode, pH meter (Jenway 3510, Staffordshire, England), Centurion K241R centrifuge (UK), Rotary evaporator (DVP TYRO 12, Germany), Vortex mixer (VELP Scientifica, Europe), Sonicator (Bandelin Sonorex RK 510S,Germany). 2.3. Standard solutions Preparation of stock standard solution of BDZ was done by accurately weighing and transferring 17.5 mg of pure BDZ to 25-mL volumetric flask. Phosphate buffer (pH 6.4) was added to the mark to gain a 5×10 –4 M BDZ solution. Different working solutions of varying strength from (5.0×10 − 5 - to 5.0×10 − 7 M) were obtained by different dilutions from the stock BDZ solution with phosphate buffer. 2.4. Procedures 2.4.1. Operational conditions of electrochemical measurements By scanning potentials, the cyclic voltammograms were recorded over range of − 0.2 to 1.4 V starting from 0.0 V using PGE working electrode versus the Ag/AgCl reference electrode. All measurements were performed in positive direction at room temperature. While for DPV determinations, the voltammograms were obtained through scanning the potential over a potential range of 0.0 to 1.3 V, with scan rate of 40 mV s − 1 , optimized pulse amplitude 75 mV, step potential 32, modulation time 50 ms, interval time 1250 ms and quiet time of 5 s. 2.4.2. Calibration curve construction into 25-mL volumetric flasks, varied aliquots of BDZ stock solution were transferred, then volumes were completed using phosphate buffer (pH 6.4) to obtain the required final concentrations of 5.0×10 − 7 , 5.0×10 − 6 , 1.0×10 − 5 , 2.0×10 − 5 , 3.0×10 − 5 , 4.0×10 − 5 and 5.0×10 − 5 M. Differential pulse voltammograms in the range from 0.0 to 1.3 V were collected under the optimized conditions. The recorded current peak height for each sample was plotted against the corresponding concentration to construct the calibration curve from which the regression equations was calculated. 2.4.3. Procedure for pharmaceutical preparation Five tablets of Octomotol (each tablet containing 110 mg of BDZ) were weighed and ground with the aid of porcelain mortar. An amount of powdered tablet equivalent to 17.5 mg of BDZ was weighed, dissolved into 5 mL of phosphate buffer (pH 6.4) then sonicated for 15 min. The solution was filtered into to a 25-mL volumetric flask and completed to mark with phosphate buffer (pH 6.4) to obtain a final concentration 5.0×10 − 4 M. Further dilutions were done with phosphate buffer to obtain different concentrations of BDZ covering the concentration range then proceed as under calibration curve construction section. The content of BDZ in tablets was calculated from the regression equation. 2.4.4. Application to human plasma A volume of half a mL of human plasma was transferred into a series of screw capped centrifugation tubes. The plasma was spiked with different concentrations of BDZ standard solution. For protein denaturation, 1.5 mL of acetonitrile was added to each tube and mixed with the spiked plasma. The tubes were vortex mixed for 1 min then centrifuged at 6000 rpm for 15 min. The residues were dissolved in 2 mL phosphate buffer (pH 6.4) and transferred into 25-mL volumetric flasks then completed to volume with the same solvent to gain final desired concentrations of 2.0× 10 − 6 , 2.0×10 − 5 , 3.0×10 − 5 and 5.0×10 − 5 M. The obtained samples were analyzed applying the same procedure as mentioned under the section of construction of calibration curve of BDZ. The corresponding regression equation was used to determine the BDZ concentration. 3. Results and discussions In the present study simple, selective and sensitive differential pulse voltammetric method was developed for quantification of BDZ in its pure form, pharmaceutical dosage form and in spiked human plasma using pencil graphite sensor without any modification which provides improved advantages such as being widely available, cheap electrode, simple in application, disposable, highly selective and sensitive with low detection limit. The electrochemical oxidation of BDZ at PGE in phosphate buffer (pH 6.4) was examined using cyclic and DPV between 0.0–1.3 V against Ag/AgCl reference electrode. 3.1. Electrochemical character of BDZ Initially, the voltammetric behavior of BDZ was studied at two different types of electrodes i) carbon paste electrode and ii) PGE. PGE showed reproducible peak and enhanced peak current that can be contributed to the high kinetic electron transfer rate at sp 2 surface of PGE towards oxidation of 5.0×10 − 5 M of BDZ in phosphate buffer (pH 6.4) using cyclic voltammetry at scan rate 40 mV s − 1 . Figure (2) shows the differential pulse (DP) voltammogram of 5.0×10 − 5 M BDZ in phosphate buffer (pH 6.4) at PGE, that reveals the existence of irreversible anodic oxidation peak at PGE ( E p = 0.56 V vs Ag/AgCl). 3.2. Influence of scan rate Cyclic voltammograms of BDZ in phosphate buffer (pH 6.4) were collected at varied scan rates using PGE to investigate how the change in the scan rate affects the peak current of BDZ. Figure 3 (a) demonstrates the influence of scan rate (20 − 80 mV/s) on the anodic signal of 5.0×10 − 4 M of BDZ. It was observed that on increasing the scan rate, the anodic oxidation signal (E p ) was shifted to higher positive values, which is commonly observed for irreversible oxidation reactions. The oxidation peak current dependence on the scan rate was studied. It was observed that, on increasing the scan rate, a linear dependency of the peak current (A) with the square root of the scan rate (ʋ 1/2 ) was observed in a range from 20 to 80 mV/s Fig. 3 (b) . Straight line was gained applying the equation: I p /µA = 9.3758 (ν 1/2 ) – 0.3213 (R 2 = 0.9866) The obtained results revealed that the electrochemical behavior of BDZ is typically diffusion controlled. The previous conclusion was also confirmed by plotting of logarithm the peak current (log A) against logarithm the scan rate (log ν) where a straight line was obtained, Fig. 3 (c) , with the following equation: log A = 0.4731(logν) + 1.001 (R 2 = 0.9697) The slope (α) is nearly close to 0.5 (theoretical value) which supported that the anodic oxidation of BDZ at PGE surface is diffusion controlled process only[ 24 ]. The appearance of the anodic peak is most probably linked to the oxidation of the secondary amine in BDZ according to what was reported for similar compounds that were utilized to understand the electrochemical oxidation mechanism of BDZ [ 25 ]. Scheme 1 illustrates the possible mechanism by which electron transfer takes place during the oxidation process. 3.3. Influence of pH Different buffer systems, such as phosphate buffer and Britton Robinson buffer, were used to examine the electrochemical behavior of BDZ; the greatest outcomes were attained in phosphate buffer at pH values between 5.0 and 8.0. The effect of various pH values on the peak potential (E p ) of BDZ was evaluated either by cyclic and DPV. The anodic oxidation peak current increases as the pH of the solution increases from pH 5.0 to 8.0. The optimal peak current response was obtained at pH (6.4). The linear dependency of the peak potential (E p ) on pH was expressed by regression equation Figure (4) : E p =0.012 pH + 0.6086 (R 2 = 0.9996) 3.4. Method validation The applied method had been validated regarding to the ICH guidelines [ 26 ]. Linearity Construction of calibration curve of the proposed DPV method was performed relating the obtained current peak height of BDZ to its molar concentrations. The concentration range is linear from 5.0×10 − 7 to 5.0×10 − 5 M as shown in Figure (5). The Correlation coefficient was 0.9995 which indicates excellent linearity as illustrated in Table (1). Limit of detection (LOD) and limit of quantitation (LOQ) LOD was found to be 1.6×10 − 7 M while LOQ was found to be 5.3× 10 − 7 M as presented in Table (1). The small LOD and LOQ values are an indication of high sensitivity of the method. Accuracy The accuracy of the suggested method was evaluated by measuring the current peak height of BDZ at three concentration levels (5.0×10 − 5 , 5.0×10 − 6 and 5.0×10 − 7 M) three times. The obtained results were represented in Table (1) exhibiting an excellent accuracy. Precision The current peak height of three various concentrations of BDZ (5.0×10 − 5 , 5.0×10 − 6 and 5.0×10 − 7 M) were measured three times on the same day for assessment of the repeatability and on three sequential days for evaluation of intermediates precision. The calculated relative standard deviation (RSD %) were within the acceptable limit (˂2%) which confirm the good precision of the method Table (1). Table 1 Analytical regression data and validation parameters for the analysis of pure BDZ by the proposed differential pulse voltammetric method. Parameters BDZ Linearity range (M) 5.0×10 − 7 - 5.0×10 − 5 Correlation coefficient (r) 0.9995 Slope 1.5705 Intercept 1.2221×10 − 6 LOD (M) 1.6 ×10 − 7 LOQ (M) 5.3×10 − 7 Accuracy (R %) 98.41 Precision RSD% of intra-day Precision (Repeatability) a RSD% of inter-day (Intermediate Precision) b 1.8436 2.2796 a RSD% triplicate analysis of (5.0×10 − 5 , 5.0×10 − 6 and 5.0×10 − 7 M) of BDZ applying the suggested method on the same day. b RSD% triplicate analysis of (5.0×10 − 5 , 5.0×10 − 6 and 5.0×10 − 7 M) of BDZ applying the suggested method on three sequential days. 3.5. Application to pharmaceutical dosage form The applicability of the suggested DPV method was confirmed by the quantitative analysis of BDZ in Octomotol tablets. Voltammograms of different concentrations of Octomol tablets solution within the linearity range were recorded and no interference was observed from commonly present excipients. Additionally, the standard addition technique was utilized to confirm the validity of the methods and the obtained recovery % and RSD % showed satisfactory findings, Table (2) . Accordingly, BDZ can be determined in its pharmaceutical formulation on PGE applying the proposed methods. Table 2 Assay of BDZ in Octomotol tablet applying the suggested differential pulse voltammetric method and applying the standard addition technique. Dosage Form %Recovery a ± RSD Standard addition BDZ Taken (M) Added (M) Found (M) Recovery a % BDZ in Octomotol tablet* 99.65 ± 0.704 5.0×10 − 5 1.0×10 − 5 0.98×10 − 5 98 2.0×10 − 5 1.98×10 − 5 99 3.0×10 − 5 2.95×10 − 5 98.33 Mean ± RSD 98.44 ± 0.517 * Batch No. ( B-02140317 ) a Average of 5 determinations. 3.6. Statistical comparison The data were statistically compared to the reported method using both t and F tests. The results of comparing the mean and variance of the two methods showed that there was not any statistically significant difference between the results from the suggested methods and those from the reported method [ 10 ] as shown in Table (3). Table 3 Statistical comparison of the %recovery results for determination of BDZ in Octomotol tablets applying the proposed differential pulse voltammetric method and the reported method. Parameters Suggested method Reported method c [10] N 5 5 Mean a 99.65 99.03 SD 0.70 0.43 Student’s t -test (2.31) b 1.67 —— F -value (6.39) b 2.59 —— a Average of 5 experiments. b tabulated values of t and F at P = 0.05 c HPLC: C18 column, methanol: water: acetonitrile (20:30:50, by volume), flow rate of 1.0 mL.min − 1 with UV detection at 235 nm. 3.7. Analysis of spiked human plasma The higher sensitivity of the applied voltametric methods was proved by analyzing human plasma samples spiked with different concentrations of BDZ. Table 4 displays the satisfactory results of quantification of BDZ in human plasma. The lowest concentration that the proposed method can detect was 5 × 10 − 7 M that was less than the C max value of BDZ (15.5×10 − 6 M after administration of BDZ 110 mg tablet) [ 27 ], so the suggested method can be beneficially applied for the estimation of BDZ in real samples of human plasma permitting pharmacokinetic study of BDZ with no interference from endogenous plasma matrix. Table 4 Assay results of human plasma spiked with different concentrations of BDZ applying the suggested differential pulse voltammetric method. Added (M) Found * (M) Recovery% 2.0×10 − 6 1.91×10 − 6 95.67 2.0×10 − 5 1.94×10 − 5 96.84 3.0×10 − 5 2.90×10 − 5 96.51 5.0×10 − 5 5.64×10 − 5 94.06 Mean ± RSD 95.77 ± 1.296 * Average of 3 determinations. 3.8. Assessment of the greenness using the analytical Eco-Scale The analytical Eco-scale scoring was adopted to assess the greenness of the proposed PGE sensor [ 28 ]. The analytical Eco-scale is based on assigning penalty points (PPs) for each parameter of the analytical methodology if it did not agree with the typical green analysis. Different parameters include: the reagents used (hazards and amount), Instrument (hazards, energy consumption during analysis, waste). Then the penalty points were subtracted from 100 to get the analytical Eco-scale for the analytical procedures [ 29 ]. High value of the analytical Eco-scale indicates the high greenness of the analytical process. Table (5) shows 10 points for the proposed PGE sensor which confirmed an excellent greenness of the method since it consumes less toxic reagents with low yield of wastes while reported HPLC method gained 26 points showing acceptable greenness. Table 5 Analytical Eco-scale score for the proposed sensor using differential pulse voltammetric method compared to the reported method. Parameter Penalty points (PPs) Proposed DPV method Reported HPLC method c [10] Solvent phosphate buffer Acetonitrile Water Methanol 0 4 - - - 8 0 12 Instrument a Energy Occupational hazards Waste 0 0 6 0 0 6 Total PPs Σ10 Σ 26 Analytical Eco-scale score b 90 Excellent green analysis 74 Acceptable green analysis a Energy consumption is ≤ 0.1 kWh /sample, hazards (Analytical process hermitization) and wastes are 1–10 ml and not treated. b Eco-scale score > 75: excellent green analysis, > 50: acceptable green analysis and ˂ 50: inadequate green analysis. c HPLC: C18 column, methanol: water: acetonitrile (20:30:50, by volume), flow rate of 1.0 mL.min − 1 with UV detection at 235 nm. 4. Conclusion Both cyclic and differential pulse voltammetric techniques were employed to investigate and quantify of BDZ in pharmaceuticals and in spiked human plasma using PGE as a working electrode. The proposed PGE sensor is distinguished from the previously described HPLC method by its simplicity and reproducibility. Using pencil graphite electrode has the advantages of being widely available, economic, low technology, disposable, good mechanical rigidity, convenient to use, renewable, time saving. From a financial perspective, all utilized analytical reagents are affordable and accessible in all quality control units. Moreover, the developed DPV method showed much greenness than the reported HPLC method as it gained high total score than HPLC method by using Eco-scale scoring tool in greenness assessment. Also, with respect to the previously published HPLC approach, the proposed DPV method was proved to be highly sensitive and quick for determination of BDZ in micromolar concentration, allowing for future employment in pharmacokinetics research. Declarations Availability of data and materials: All data obtained during this study are included in this published article. Acknowledgement Not applicable Funding Open access funding provided by The Science, Technology & Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB). Author information Authors and affiliations Manal S. Elmasry&Wafaa S. Hassan, Analytical Chemistry Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt, Israa M. Nour , Pharmaceutical Chemistry Department, Faculty of Pharmacy, Egyptian Russian University, Badr, 11829, Egypt Hanan A. Merey&Amr M. Mahmoud, Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El-Aini, Cairo, 11562, Egypt Hanan A. Merey, Analytical Chemistry Department, Faculty of Pharmacy, October 6 University, 6 October City, Giza, 12585, Egypt Contributions Manal S. Elmasry: Supervision Wafaa S. Hassan: Supervision Israa M. Nour: Conceptualization, Supervision, Methodology, Writing – review & editing. Hanan A. Merey: Supervision Amr M. Mahmoud: Validation, Conceptualization, Methodology, Software, Writing – original draft. Corresponding author Correspondence to Israa M. Nour Competing interests The authors declare no competing interests. Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References Aletaha, D. & Smolen, J. S. Diagnosis and management of rheumatoid arthritis: A review. Jama 320 , 13 (2018). Strand, V. & Khanna, D. The impact of rheumatoid arthritis and treatment on patients' lives. Clinical & Experimental Rheumatology , 28 , 3 (2010), S32–S40 . Kwoh, C. et al. American College of Rheumatology Subcommittee on Rheumatoid Arthritis Guidelines. Guidelines for the management of rheumatoid arthritis: 2002 update. Arthritis Rheumatol. 46 , 328–346 (2002). Sweetman, S. C. & Martindale The complete drug reference (Pharmaceutical, 2009). 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Nour","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+0lEQVRIiWNgGAWjYBAC+QY4M4GBmaECwpTAp4UNwQRpOUOyFsY2YrTwn3344QfDNnnd9uRj0oXzbPINDjAfvM3DYGPXgEuLRLqxZA/DbcNtZ56lSc/clma54QBbsjUPQ1oybi1sDBK8/24zbruRYybNu+2wgcEBHjNpHobDybgddoz55x+G2/YQLXP+A7XwfwNq+Y9bC0MaG1DB7USIloYDIFtAIgfscGqRSGOzlmG4nQz0C9ALx5INJA+zGVvOMUhOwKVFvv8Y8803DLdttx1PBgZUjZ0B3/HmhzfeVNjZ49KCBTCDCAOGxAYS9EAAKbaMglEwCkbB8AYAHl9Ov9HMeM8AAAAASUVORK5CYII=","orcid":"","institution":"Egyptian Russian University","correspondingAuthor":true,"prefix":"","firstName":"Israa","middleName":"M.","lastName":"Nour","suffix":""},{"id":496778289,"identity":"edf27d7b-3d4a-47e4-8464-2c5b1879d585","order_by":2,"name":"Wafaa S. Hassan","email":"","orcid":"","institution":"Zagazig University","correspondingAuthor":false,"prefix":"","firstName":"Wafaa","middleName":"S.","lastName":"Hassan","suffix":""},{"id":496778290,"identity":"e5f3e6a6-7f04-4cd2-afa2-9a67325483bc","order_by":3,"name":"Hanan A. Merey","email":"","orcid":"","institution":"Cairo University","correspondingAuthor":false,"prefix":"","firstName":"Hanan","middleName":"A.","lastName":"Merey","suffix":""},{"id":496778291,"identity":"24186bae-7b1c-44f4-8e59-a698afe1169c","order_by":4,"name":"Amr M. Mahmoud","email":"","orcid":"","institution":"Cairo University","correspondingAuthor":false,"prefix":"","firstName":"Amr","middleName":"M.","lastName":"Mahmoud","suffix":""}],"badges":[],"createdAt":"2025-07-13 11:23:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7112930/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7112930/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88773485,"identity":"d0295ea4-53a3-485e-b187-2168418b15f5","added_by":"auto","created_at":"2025-08-11 09:57:21","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":29033,"visible":true,"origin":"","legend":"\u003cp\u003eChemical structure of bumadizone calcium hemihydrate\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7112930/v1/889e21de00a3b44deed0ea99.jpg"},{"id":88773486,"identity":"8b61b6b6-a477-4510-8358-82145f3621bf","added_by":"auto","created_at":"2025-08-11 09:57:21","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":49909,"visible":true,"origin":"","legend":"\u003cp\u003eDifferential pulse voltammogram of 5\u003cu\u003e.0\u003c/u\u003e×10\u003csup\u003e-5\u003c/sup\u003e M BDZ in phosphate buffer pH 6.4 at PGE. The peak at 0.56 (E\u003csub\u003ep\u003c/sub\u003e = 0.56 V vs Ag/AgCl)\u003cu\u003e.\u003c/u\u003e\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7112930/v1/269e99dcff4fcfb173d2cbc2.jpg"},{"id":88773487,"identity":"9116d571-0a3d-4778-9822-3b3f517fa19a","added_by":"auto","created_at":"2025-08-11 09:57:21","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":76363,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Cyclic voltammograms of 5.0×10\u003csup\u003e-4\u003c/sup\u003e M BDZ at different scan rates (20-80 mV/s) on PGE, (b) Dependency of peak current of BDZ on the square root of scan rate (ʋ\u003csup\u003e1/2\u003c/sup\u003e) and (c) Dependency of log peak current of BDZ (Log A) on the log scan rate (Log ʋ)\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7112930/v1/3d107e75d81855c864070a68.jpg"},{"id":88773488,"identity":"2a976a87-cc5f-49b1-ad55-f21ffdae9bc7","added_by":"auto","created_at":"2025-08-11 09:57:21","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":22645,"visible":true,"origin":"","legend":"\u003cp\u003eDependency of peak potential of BDZ on pH\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7112930/v1/e3d4c99f340f9b537d387824.jpg"},{"id":88775343,"identity":"d01f4668-0eb1-4b64-b3dc-0ab68cda1e6a","added_by":"auto","created_at":"2025-08-11 10:05:21","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":45012,"visible":true,"origin":"","legend":"\u003cp\u003eDifferential pulse voltammetric responses recorded on PGE for different concentrations of BDZ (5.0×10\u003csup\u003e-7 \u003c/sup\u003eto 5.0×10\u003csup\u003e-5 \u003c/sup\u003eM) in phosphate buffer (pH 6.4)\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7112930/v1/5d9c457f3d3e10212970f769.jpg"},{"id":88847798,"identity":"c2d7663b-aec5-4022-ac09-ff79e30690d2","added_by":"auto","created_at":"2025-08-12 04:31:33","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1383608,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7112930/v1/5c8c464b-8114-4db5-9fcd-617e64224ecb.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Eco-friendly Electrochemical Sensor for Quantification of Bumadizone in Pure, Pharmaceutical Dosage Form and in Spiked Human Plasma Using Pencil Graphite Electrode","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eRheumatoid arthritis (RA) is an autoimmune chronic inflammatory condition that affects about 0.5 to 1% of people worldwide and commonly cause joint deformity, damage and can finally leads to disability [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. RA has a negative impacts on patient\u0026rsquo;s life quality regarding physical aspect (continual pain, stiffness or even disability), financial aspect (high-cost therapy) and social aspect (depression, dependency, impaired social relationship) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Pain relieve is one of the main concerns of patients suffering from RA as persistent pain make them seek the medical therapy. Currently, drug management for RA includes symptomatic treatment with analgesics, non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying anti-rheumatic drugs (DMARDs). NSAIDs are cyclooxygenase isoforms inhibitors (COXs) that acts via reducing joint swelling and decreasing pain, but they cannot prevent progressive joint destruction [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eBumadizone calcium hemihydrate (BDZ) chemical structure is shown in \u003cb\u003eFigure (1)\u003c/b\u003e is dicalcium; 2- [aniline (phenyl) carbamoyl] hexanoate; hydrate [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. It is one of the NSAIDs that is used for to treat rheumatic disorders and post-traumatic edema through inhibition of cyclooxygenase by blocking the synthesis of prostaglandins [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Literature reviews reports that there is a few analytical techniques for quantitative determination of BDZ either alone or in presence of its alkaline degradation including spectrophotometric [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], Fourier transform-infrared [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], fluorometric [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and chromatographic methods [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Interestingly, none of the reported methods were reported for the electrochemical estimation of BDZ. Compared to the reported methods, electrochemical methods have advantages of being simple, highly sensitive, low cost, easy to be applied and rapid compared to the reported methods which are time consuming, expensive and having complex procedures.\u003c/p\u003e\u003cp\u003eVoltammetric sensors have been widely employed for the electroanalytical quantitative analysis of various analytes including drugs, environmental pollutants, and biomarkers. The sensors are based on measuring the current peak height produced as a function of applied voltage at working electrode (versus a reference electrode) [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The choice of suitable working electrode should be carefully planned to achieve maximum sensitivity and reproducibility of the analysis. Different voltammetric electrode substrates have been reported include carbon past electrode, mercury film electrode, gold electrode, glassy carbon electrode, platinum electrode among others [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Each type of electrode has its unique sensitivity and detection limit.\u003c/p\u003e\u003cp\u003eThere is an emerging interest for utilizing pencil graphite electrodes (PGEs) as substrates for the fabrication of electrochemical sensors, this can attributed to the advantages of PGEs such as: commercial availability, disposable, high conductance, high sensitivity, diminished background current, PGE surfaces can be easily modified with metals nanoparticles, polymers, and other nanoparticles. Many reviews have been published to highlight the recent progress of using PGEs in various fields including pharmaceutical, medicinal, environmental, etc.\u003c/p\u003e\u003cp\u003eIn this work, simple and sensitive cyclic voltammetric (CV) method has been used to study the oxidation behaviour of BDZ, and differential pulse voltammetry was developed for quantification of BDZ in pure, pharmaceutical dosage form and in spiked human plasma using pencil graphite electrode (PGE) surface. Pencil graphite sensor was used without any modification which provides improved advantages such as being widely available, cheap electrode, simple in application, disposable, highly selective and sensitive with low detection limit.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1. Material and reagents:\u003c/h2\u003e\u003cp\u003eBDZ standard was kindly gifted by October Pharma company, Cairo, Egypt (with certified purity 99.86%). Octomotol\u0026reg; tablets, contain 110 mg of Bumadizone calcium hemihydrate (Bumadizone) as labeled, (batch no. B-02140317), October Pharma company, Cairo, Egypt, purchased from local market. Analytical grade solvents as ortho-phosphoric acid, sodium hydroxide, di-potassium hydrogen phosphate and acetonitrile were used (Sigma-Aldrich, Darmstadt, Germany). Britton\u0026ndash;Robinson buffer (BRB) solutions (pH 2.0\u0026ndash;9.0) were prepared by mixing a solution of (0.04 M phosphoric acid, 0.04 M glacial acetic acid and 0.04 M boric acid) and the appropriate pH value was adjusted by adding the necessary amount of 0.2 M NaOH solution. Water used was bi-distilled. Human plasma was brought from the Holding Company for Biological Products and Vaccines (VACSERA, Egypt).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2. Apparatus\u003c/h2\u003e\u003cp\u003eAll voltametric determinations were done using a Metrohm Autolab potentiostat/ galvanostat PGSTAT204 electrochemical workstation. The electrochemical cell was PC-controlled and coupled with NOVA 1.11 software for electrochemistry. Ag/AgCl electrode was used as reference electrode, while the used counter electrode was a Pt wire. PGE (Tombow Ultra-Polymer, 2B, Japan) with 0.9 mm diameter and 60 mm of total length was used as the working electrode, pH meter (Jenway 3510, Staffordshire, England), Centurion K241R centrifuge (UK), Rotary evaporator (DVP TYRO 12, Germany), Vortex mixer (VELP Scientifica, Europe), Sonicator (Bandelin Sonorex RK 510S,Germany).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3. Standard solutions\u003c/h2\u003e\u003cp\u003ePreparation of stock standard solution of BDZ was done by accurately weighing and transferring 17.5 mg of pure BDZ to 25-mL volumetric flask. Phosphate buffer (pH 6.4) was added to the mark to gain a 5\u0026times;10\u003csup\u003e\u0026ndash;4\u003c/sup\u003e M BDZ solution. Different working solutions of varying strength from (5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e - to 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e M) were obtained by different dilutions from the stock BDZ solution with phosphate buffer.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.4. Procedures\u003c/h2\u003e\u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\u003ch2\u003e2.4.1. Operational conditions of electrochemical measurements\u003c/h2\u003e\u003cp\u003eBy scanning potentials, the cyclic voltammograms were recorded over range of \u0026minus;\u0026thinsp;0.2 to 1.4 V starting from 0.0 V using PGE working electrode versus the Ag/AgCl reference electrode. All measurements were performed in positive direction at room temperature. While for DPV determinations, the voltammograms were obtained through scanning the potential over a potential range of 0.0 to 1.3 V, with scan rate of 40 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, optimized pulse amplitude 75 mV, step potential 32, modulation time 50 ms, interval time 1250 ms and quiet time of 5 s.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\u003ch2\u003e2.4.2. Calibration curve construction\u003c/h2\u003e\u003cp\u003einto 25-mL volumetric flasks, varied aliquots of BDZ stock solution were transferred, then volumes were completed using phosphate buffer (pH 6.4) to obtain the required final concentrations of 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e, 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e, 1.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 2.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 3.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 4.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e and 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e M. Differential pulse voltammograms in the range from 0.0 to 1.3 V were collected under the optimized conditions. The recorded current peak height for each sample was plotted against the corresponding concentration to construct the calibration curve from which the regression equations was calculated.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\u003ch2\u003e2.4.3. Procedure for pharmaceutical preparation\u003c/h2\u003e\u003cp\u003eFive tablets of Octomotol (each tablet containing 110 mg of BDZ) were weighed and ground with the aid of porcelain mortar. An amount of powdered tablet equivalent to 17.5 mg of BDZ was weighed, dissolved into 5 mL of phosphate buffer (pH 6.4) then sonicated for 15 min. The solution was filtered into to a 25-mL volumetric flask and completed to mark with phosphate buffer (pH 6.4) to obtain a final concentration 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M. Further dilutions were done with phosphate buffer to obtain different concentrations of BDZ covering the concentration range then proceed as under calibration curve construction section. The content of BDZ in tablets was calculated from the regression equation.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section3\"\u003e\u003ch2\u003e\u003cb\u003e2.4.4. Application to human plasma\u003c/b\u003e\u003c/h2\u003e\u003cp\u003eA volume of half a mL of human plasma was transferred into a series of screw capped centrifugation tubes. The plasma was spiked with different concentrations of BDZ standard solution. For protein denaturation, 1.5 mL of acetonitrile was added to each tube and mixed with the spiked plasma. The tubes were vortex mixed for 1 min then centrifuged at 6000 rpm for 15 min. The residues were dissolved in 2 mL phosphate buffer (pH 6.4) and transferred into 25-mL volumetric flasks then completed to volume with the same solvent to gain final desired concentrations of 2.0\u0026times; 10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e, 2.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 3.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e and 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e M. The obtained samples were analyzed applying the same procedure as mentioned under the section of construction of calibration curve of BDZ. The corresponding regression equation was used to determine the BDZ concentration.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"3. Results and discussions","content":"\u003cp\u003eIn the present study simple, selective and sensitive differential pulse voltammetric method was developed for quantification of BDZ in its pure form, pharmaceutical dosage form and in spiked human plasma using pencil graphite sensor without any modification which provides improved advantages such as being widely available, cheap electrode, simple in application, disposable, highly selective and sensitive with low detection limit. The electrochemical oxidation of BDZ at PGE in phosphate buffer (pH 6.4) was examined using cyclic and DPV between 0.0\u0026ndash;1.3 V against Ag/AgCl reference electrode.\u003c/p\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e3.1. Electrochemical character of BDZ\u003c/h2\u003e\u003cp\u003eInitially, the voltammetric behavior of BDZ was studied at two different types of electrodes i) carbon paste electrode and ii) PGE. PGE showed reproducible peak and enhanced peak current that can be contributed to the high kinetic electron transfer rate at sp\u003csup\u003e2\u003c/sup\u003e surface of PGE towards oxidation of 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e M of BDZ in phosphate buffer (pH 6.4) using cyclic voltammetry at scan rate 40 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003e\u003cb\u003eFigure (2)\u003c/b\u003e shows the differential pulse (DP) voltammogram of 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e M BDZ in phosphate buffer (pH 6.4) at PGE, that reveals the existence of irreversible anodic oxidation peak at PGE (\u003cem\u003eE\u003c/em\u003e\u003csub\u003ep\u003c/sub\u003e = 0.56 V vs Ag/AgCl).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e3.2. Influence of scan rate\u003c/h2\u003e\u003cp\u003eCyclic voltammograms of BDZ in phosphate buffer (pH 6.4) were collected at varied scan rates using PGE to investigate how the change in the scan rate affects the peak current of BDZ. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e \u003cb\u003e(a)\u003c/b\u003e demonstrates the influence of scan rate (20\u0026thinsp;\u0026minus;\u0026thinsp;80 mV/s) on the anodic signal of 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M of BDZ. It was observed that on increasing the scan rate, the anodic oxidation signal (E\u003csub\u003ep\u003c/sub\u003e) was shifted to higher positive values, which is commonly observed for irreversible oxidation reactions. The oxidation peak current dependence on the scan rate was studied. It was observed that, on increasing the scan rate, a linear dependency of the peak current (A) with the square root of the scan rate \u003cb\u003e(ʋ\u003c/b\u003e\u003csup\u003e\u003cb\u003e1/2\u003c/b\u003e\u003c/sup\u003e\u003cb\u003e)\u003c/b\u003e was observed in a range from 20 to 80 mV/s Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e \u003cb\u003e(b)\u003c/b\u003e. Straight line was gained applying the equation:\u003c/p\u003e\u003cp\u003eI\u003csub\u003ep\u003c/sub\u003e/\u0026micro;A\u0026thinsp;=\u0026thinsp;9.3758 (ν\u003csup\u003e1/2\u003c/sup\u003e) \u0026ndash; 0.3213 (R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.9866)\u003c/p\u003e\u003cp\u003eThe obtained results revealed that the electrochemical behavior of BDZ is typically diffusion controlled. The previous conclusion was also confirmed by plotting of logarithm the peak current (log A) against logarithm the scan rate (log ν) where a straight line was obtained, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e \u003cb\u003e(c)\u003c/b\u003e, with the following equation:\u003c/p\u003e\u003cp\u003elog A\u0026thinsp;=\u0026thinsp;0.4731(logν)\u0026thinsp;+\u0026thinsp;1.001 (R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.9697)\u003c/p\u003e\u003cp\u003eThe slope (α) is nearly close to 0.5 (theoretical value) which supported that the anodic oxidation of BDZ at PGE surface is diffusion controlled process only[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe appearance of the anodic peak is most probably linked to the oxidation of the secondary amine in BDZ according to what was reported for similar compounds that were utilized to understand the electrochemical oxidation mechanism of BDZ [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the possible mechanism by which electron transfer takes place during the oxidation process.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003e3.3. Influence of pH\u003c/h2\u003e\u003cp\u003eDifferent buffer systems, such as phosphate buffer and Britton Robinson buffer, were used to examine the electrochemical behavior of BDZ; the greatest outcomes were attained in phosphate buffer at pH values between 5.0 and 8.0. The effect of various pH values on the peak potential (E\u003csub\u003ep\u003c/sub\u003e) of BDZ was evaluated either by cyclic and DPV. The anodic oxidation peak current increases as the pH of the solution increases from pH 5.0 to 8.0. The optimal peak current response was obtained at pH (6.4). The linear dependency of the peak potential (E\u003csub\u003ep\u003c/sub\u003e) on pH was expressed by regression equation \u003cb\u003eFigure (4)\u003c/b\u003e:\u003c/p\u003e\u003cp\u003eE\u003csub\u003ep\u003c/sub\u003e =0.012 pH\u0026thinsp;+\u0026thinsp;0.6086 (R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.9996)\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003ch2\u003e3.4. Method validation\u003c/h2\u003e\u003cp\u003eThe applied method had been validated regarding to the ICH guidelines [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003cb\u003eLinearity\u003c/b\u003e\u003c/p\u003e\u003cp\u003eConstruction of calibration curve of the proposed DPV method was performed relating the obtained current peak height of BDZ to its molar concentrations. The concentration range is linear from 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e to 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e M as shown in \u003cb\u003eFigure (5).\u003c/b\u003e The Correlation coefficient was 0.9995 which indicates excellent linearity as illustrated in \u003cb\u003eTable\u0026nbsp;(1).\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eLimit of detection (LOD) and limit of quantitation (LOQ)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eLOD was found to be 1.6\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e M while LOQ was found to be 5.3\u0026times; 10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003eM as presented in \u003cb\u003eTable\u0026nbsp;(1).\u003c/b\u003e The small LOD and LOQ values are an indication of high sensitivity of the method.\u003c/p\u003e\u003cp\u003e\u003cb\u003eAccuracy\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe accuracy of the suggested method was evaluated by measuring the current peak height of BDZ at three concentration levels (5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e and 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e M) three times. The obtained results were represented in \u003cb\u003eTable\u0026nbsp;(1)\u003c/b\u003e exhibiting an excellent accuracy.\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrecision\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe current peak height of three various concentrations of BDZ (5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e and 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e M) were measured three times on the same day for assessment of the repeatability and on three sequential days for evaluation of intermediates precision. The calculated relative standard deviation (RSD %) were within the acceptable limit (˂2%) which confirm the good precision of the method \u003cb\u003eTable\u0026nbsp;(1).\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eAnalytical regression data and validation parameters for the analysis of pure BDZ by the proposed differential pulse voltammetric method.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBDZ\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLinearity range (M)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e- 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCorrelation coefficient (r)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.9995\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSlope\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.5705\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eIntercept\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.2221\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLOD (M)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.6 \u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLOQ (M)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.3\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAccuracy (R %)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e98.41\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePrecision\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRSD% of intra-day Precision (Repeatability)\u003c/b\u003e\u003csup\u003e\u003cb\u003ea\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRSD% of inter-day (Intermediate Precision)\u003c/b\u003e \u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.8436\u003c/p\u003e\u003cp\u003e2.2796\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e RSD% triplicate analysis of (5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e and 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e M) of BDZ applying the suggested method on the same day.\u003c/p\u003e\u003cp\u003e\u003csup\u003eb\u003c/sup\u003e RSD% triplicate analysis of (5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e and 5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e M) of BDZ applying the suggested method on three sequential days.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\u003ch2\u003e3.5. Application to pharmaceutical dosage form\u003c/h2\u003e\u003cp\u003eThe applicability of the suggested DPV method was confirmed by the quantitative analysis of BDZ in Octomotol tablets. Voltammograms of different concentrations of Octomol tablets solution within the linearity range were recorded and no interference was observed from commonly present excipients. Additionally, the standard addition technique was utilized to confirm the validity of the methods and the obtained recovery % and RSD % showed satisfactory findings, \u003cb\u003eTable\u0026nbsp;(2)\u003c/b\u003e. Accordingly, BDZ can be determined in its pharmaceutical formulation on PGE applying the proposed methods.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eAssay of BDZ in Octomotol tablet applying the suggested differential pulse voltammetric method and applying the standard addition technique.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eDosage Form\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e%Recovery \u003csup\u003ea\u003c/sup\u003e \u0026plusmn; RSD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c6\" namest=\"c3\"\u003e\u003cp\u003eStandard addition\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBDZ Taken (M)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdded (M)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eFound (M)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eRecovery \u003csup\u003ea\u003c/sup\u003e %\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003e\u003cb\u003eBDZ in Octomotol tablet*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e99.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.704\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.98\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e98\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.98\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.95\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e98.33\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;RSD\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e98.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.517\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003csup\u003e*\u003c/sup\u003e Batch No. \u003cb\u003e(\u003c/b\u003eB-02140317\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003csup\u003ea\u003c/sup\u003eAverage of 5 determinations.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\u003ch2\u003e3.6. Statistical comparison\u003c/h2\u003e\u003cp\u003eThe data were statistically compared to the reported method using both t and F tests. The results of comparing the mean and variance of the two methods showed that there was not any statistically significant difference between the results from the suggested methods and those from the reported method [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] as shown in Table\u0026nbsp;(3).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eStatistical comparison of the %recovery results for determination of BDZ in Octomotol tablets applying the proposed differential pulse voltammetric method and the reported method.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSuggested method\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eReported method\u003csup\u003ec [10]\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003csup\u003e\u003cb\u003ea\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e99.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e99.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSD\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.70\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.43\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eStudent\u0026rsquo;s\u003c/b\u003e \u003cb\u003et\u003c/b\u003e\u003cb\u003e-test\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003e(2.31)\u003c/b\u003e \u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e\u0026mdash;\u0026mdash;\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eF\u003c/b\u003e\u003cb\u003e-value\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003e(6.39)\u003c/b\u003e \u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e\u0026mdash;\u0026mdash;\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Average of 5 experiments.\u003c/p\u003e\u003cp\u003e\u003csup\u003eb\u003c/sup\u003e tabulated values of \u003cem\u003et\u003c/em\u003e and \u003cem\u003eF\u003c/em\u003e at P\u0026thinsp;=\u0026thinsp;0.05\u003c/p\u003e\u003cp\u003e\u003csup\u003ec\u003c/sup\u003e HPLC: C18 column, methanol: water: acetonitrile (20:30:50, by volume), flow rate of 1.0 mL.min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with UV detection at 235 nm.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003e3.7. Analysis of spiked human plasma\u003c/h2\u003e\u003cp\u003eThe higher sensitivity of the applied voltametric methods was proved by analyzing human plasma samples spiked with different concentrations of BDZ. Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e displays the satisfactory results of quantification of BDZ in human plasma. The lowest concentration that the proposed method can detect was 5 \u0026times; 10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e M that was less than the C\u003csub\u003emax\u003c/sub\u003e value of BDZ (15.5\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e M after administration of BDZ 110 mg tablet) [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], so the suggested method can be beneficially applied for the estimation of BDZ in real samples of human plasma permitting pharmacokinetic study of BDZ with no interference from endogenous plasma matrix.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eAssay results of human plasma spiked with different concentrations of BDZ applying the suggested differential pulse voltammetric method.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAdded (M)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFound\u003csup\u003e*\u003c/sup\u003e (M)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRecovery%\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.91\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95.67\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.94\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e96.84\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.90\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e96.51\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5.0\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.64\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e94.06\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean \u0026plusmn; RSD\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.296\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e* Average of 3 determinations.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e\u003ch2\u003e\u003cb\u003e3.8. Assessment of the greenness using the analytical Eco-Scale\u003c/b\u003e\u003c/h2\u003e\u003cp\u003eThe analytical Eco-scale scoring was adopted to assess the greenness of the proposed PGE sensor [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The analytical Eco-scale is based on assigning penalty points (PPs) for each parameter of the analytical methodology if it did not agree with the typical green analysis. Different parameters include: the reagents used (hazards and amount), Instrument (hazards, energy consumption during analysis, waste). Then the penalty points were subtracted from 100 to get the analytical Eco-scale for the analytical procedures [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. High value of the analytical Eco-scale indicates the high greenness of the analytical process. \u003cb\u003eTable\u0026nbsp;(5)\u003c/b\u003e shows 10 points for the proposed PGE sensor which confirmed an excellent greenness of the method since it consumes less toxic reagents with low yield of wastes while reported HPLC method gained 26 points showing acceptable greenness.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eAnalytical Eco-scale score for the proposed sensor using differential pulse voltammetric method compared to the reported method.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eParameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003ePenalty points (PPs)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eProposed DPV method\u003c/b\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003eReported HPLC method\u003c/b\u003e \u003csup\u003ec \u003cb\u003e[10]\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSolvent\u003c/b\u003e\u003c/p\u003e\u003cp\u003ephosphate buffer\u003c/p\u003e\u003cp\u003eAcetonitrile\u003c/p\u003e\u003cp\u003eWater\u003c/p\u003e\u003cp\u003eMethanol\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003cp\u003e4\u003c/p\u003e\u003cp\u003e-\u003c/p\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003cp\u003e8\u003c/p\u003e\u003cp\u003e0\u003c/p\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eInstrument\u003c/b\u003e \u003csup\u003e\u003cb\u003ea\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eEnergy\u003c/p\u003e\u003cp\u003eOccupational hazards\u003c/p\u003e\u003cp\u003eWaste\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003cp\u003e0\u003c/p\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003cp\u003e0\u003c/p\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal PPs\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eΣ10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eΣ 26\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAnalytical Eco-scale score\u003c/b\u003e \u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e90\u003c/p\u003e\u003cp\u003eExcellent green analysis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e74\u003c/p\u003e\u003cp\u003eAcceptable green analysis\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Energy consumption is \u0026le;\u0026thinsp;0.1 kWh /sample, hazards (Analytical process hermitization) and wastes are 1\u0026ndash;10 ml and not treated.\u003c/p\u003e\u003cp\u003e\u003csup\u003eb\u003c/sup\u003e Eco-scale score\u0026thinsp;\u0026gt;\u0026thinsp;75: excellent green analysis, \u0026gt;\u0026thinsp;50: acceptable green analysis and ˂ 50: inadequate green analysis.\u003c/p\u003e\u003cp\u003e\u003csup\u003ec\u003c/sup\u003e HPLC: C18 column, methanol: water: acetonitrile (20:30:50, by volume), flow rate of 1.0 mL.min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with UV detection at 235 nm.\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eBoth cyclic and differential pulse voltammetric techniques were employed to investigate and quantify of BDZ in pharmaceuticals and in spiked human plasma using PGE as a working electrode. The proposed PGE sensor is distinguished from the previously described HPLC method by its simplicity and reproducibility. Using pencil graphite electrode has the advantages of being widely available, economic, low technology, disposable, good mechanical rigidity, convenient to use, renewable, time saving. From a financial perspective, all utilized analytical reagents are affordable and accessible in all quality control units. Moreover, the developed DPV method showed much greenness than the reported HPLC method as it gained high total score than HPLC method by using Eco-scale scoring tool in greenness assessment. Also, with respect to the previously published HPLC approach, the proposed DPV method was proved to be highly sensitive and quick for determination of BDZ in micromolar concentration, allowing for future employment in pharmacokinetics research.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data obtained during this study are included in this published article.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOpen access funding provided by The Science, Technology \u0026amp; Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors and affiliations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eManal S. Elmasry\u0026amp;Wafaa S. Hassan,\u0026nbsp;Analytical Chemistry Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt,\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIsraa M. Nour\u003csup\u003e,\u0026nbsp;\u003c/sup\u003ePharmaceutical Chemistry Department, Faculty of Pharmacy, Egyptian Russian University, Badr, 11829, Egypt\u003c/p\u003e\n\u003cp\u003eHanan A. Merey\u0026amp;Amr M. Mahmoud, Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El-Aini, Cairo, 11562, Egypt\u003c/p\u003e\n\u003cp\u003eHanan A. Merey,\u0026nbsp;Analytical Chemistry Department, Faculty of Pharmacy, October 6 University, 6 October City, Giza, 12585, Egypt\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eContributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eManal S. Elmasry: Supervision\u003c/p\u003e\n\u003cp\u003eWafaa S. Hassan: Supervision\u003c/p\u003e\n\u003cp\u003eIsraa M. Nour: Conceptualization, Supervision, Methodology, Writing – review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eHanan A. Merey: Supervision\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Amr M. Mahmoud: Validation, Conceptualization, Methodology, Software, Writing – original draft.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorresponding author\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence to Israa M. Nour\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of competing interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAletaha, D. \u0026amp; Smolen, J. S. Diagnosis and management of rheumatoid arthritis: A review. \u003cem\u003eJama\u003c/em\u003e \u003cb\u003e320\u003c/b\u003e, 13 (2018).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStrand, V. \u0026amp; Khanna, D. 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A., Shawky Abdelmalak, N. \u0026amp; Naguib, M. J. Bumadizone calcium dihydrate microspheres compressed tablets for colon targeting: formulation, optimization and in vivo evaluation in rabbits. \u003cem\u003eDrug Deliv.\u003c/em\u003e \u003cb\u003e22\u003c/b\u003e (3), 286\u0026ndash;297 (2015).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDicks, A. P., Hent, A. \u0026amp; Koroluk, K. J. The EcoScale as a framework for undergraduate green chemistry teaching and assessment. \u003cem\u003eGreen Chem. Lett. Rev.\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e, 1 (2018).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGałuszka, A., Migaszewski, Z. M., Konieczka, P. \u0026amp; Namieśnik, J. Analytical Eco-Scale for assessing the greenness of analytical procedures. \u003cem\u003eTRAC Trends Anal. Chem.\u003c/em\u003e \u003cb\u003e37\u003c/b\u003e, 61\u0026ndash;72 (2012).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Differential pulse and cyclic voltammetry, pencil graphite electrode, spiked human plasma, Eco-scale scoring tool, Bumadiazone","lastPublishedDoi":"10.21203/rs.3.rs-7112930/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7112930/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBumadizone calcium hemihydrate is a non-steroidal anti-inflammatory drug that is used to treat rheumatoid arthritis and post-traumatic edema through blocking prostaglandin synthesis. This work presents, for the first time, an electrochemical method has been developed for determination of bumadizone calcium hemihydrate in bulk, pharmaceutical dosage form and in spiked human plasma based on the oxidation nature of bumadiazone using pencil graphite electrode as a working electrode. The electrochemical oxidation of bumadizone at pencil graphite electrode surface in phosphate buffer pH 6.4 was investigated using cyclic and differential pulse voltammetry between -0.1 and 1.3 V against Ag/AgCl reference electrode. Experimental parameters of the suggested method as pH, scan rate, step potential, pulse amplitude and pulse width (modulation time) were well investigated and optimized. The proposed differential pulse voltametric method was found to be linear over the range 5.0×10\u003csup\u003e-7\u003c/sup\u003eto 5.0×10\u003csup\u003e-5\u003c/sup\u003eM with high correlation (r= 0.999). The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 1.6×10\u003csup\u003e-7\u003c/sup\u003e M, and 5.3×10\u003csup\u003e-7 \u003c/sup\u003eM, respectively. Using pencil graphite electrode offers extra advantages to the proposed method of being widely commercially available, cost-effective, simple, disposable and mechanically rigid electrodes. The method was found to be efficiently applicable in spiked human plasma permitting bioequivalent or pharmacokinetic study in real human plasma samples. Greenness of the proposed method was evaluated using Eco-scale scoring tool revealing excellent greenness of the analytical method.\u003c/p\u003e","manuscriptTitle":"Eco-friendly Electrochemical Sensor for Quantification of Bumadizone in Pure, Pharmaceutical Dosage Form and in Spiked Human Plasma Using Pencil Graphite Electrode","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-11 09:57:16","doi":"10.21203/rs.3.rs-7112930/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2d9c3e73-48cb-4b15-8752-8e502f4309e7","owner":[],"postedDate":"August 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":52770652,"name":"Physical sciences/Chemistry"},{"id":52770653,"name":"Physical sciences/Materials science"}],"tags":[],"updatedAt":"2025-08-12T04:23:27+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-11 09:57:16","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7112930","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7112930","identity":"rs-7112930","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}