Buffer Solution pH Research Articles

Development of an High Performance Liquid Chromatography Method for Simultaneous Determination of Hesperidin and Sodium Benzoate in Kien Ty Syrup

The Kien ty syrup is formulated from six medicinal materials, including Pericarpium Citri Reticulatae, Fructus Aurantii immaturus, Radix Codonopsis, Rhizoma Atractylodis macrocephalae, Fructus Crataegi, Fructus Hordei germinatus and sodium benzoate as a preservative. Hesperidin, a bioflavonoid found in Pericarpium Citri Reticulatae, Fructus Aurantii immaturus, is used to assess the syrup's quality in terms of assay. In this study, an HPLC method for simultaneous determination of hesperidin and sodium benzoate in Kien ty syrup was developed. The method was performed on an Agilent C18 column (250 × 4.6 mm; 5 μm) with the mobile phase being a mixture of 0.05 M phosphate buffer solution pH 5.5: acetonitrile (70:30, v/v), running in a isocratic elution mode. The flow rate was set at 1.0 mL/min, and the injection volume was 10 μL. The analytes were detected at 225 nm. The method was validated and met the requirements according to ICH, AOAC guidelines. Applying the developed quantification method, the analysis of three sirup lots revealed that the content of hesperidin and sodium benzoate ranged from 0.480-0.504 mg/mL and 2.869-2.306 mg/mL, respectively. The study results indicate that this quantification method can be applied for simultaneous determination of hesperidin and sodium benzoate in Kien ty syrup and similar products.

Assessment of in vitro diffusion of Chincha Lavan Taila: An Ayurveda medicated oil

Medicated oils are used for external as well as internal administration to treat various disorders. In Ayurvedic literature Murchhana is a procedure carried out on crude oil as treatment to enhance properties of oil. In this study, Chincha Lavan Taila a medicated formulation is prepared by two procedures Murchhita Chincha Lavan Taila (MCLT) and Amurchhita Chincha Lavan Taila (ACLT). This study aims to assess the in-vitro diffusion of Chincha Lavan Taila formulated by processed sesame oil and crude sesame oil. The in-vitro rate and extent of permeability of drug dosage forms are good markers to access the absorbance of the drug. The objective of this study is to evaluate the drug release of both oils by using in- vitro absorbance methodology of Franz diffusion cell apparatus. The in- vitro absorbance was studied in Franz diffusion cell apparatus at pH 3 and pH 8. The samples were collected and analysed under UV spectrophotometer to note absorbance of oil at different wavelength. It was noted that in the buffer solution of pH 8, there was maximum absorbance of all the samples. This experimental study shows that both formulations have well sustained absorption through gastrointestinal tract. The results indicate that the rate of absorption exhibited to be higher in MCLT compared to ACLT. This work helps to develop a new method to evaluate intestinal absorption and compare formulation for therapeutic efficacy and drug absorbance.

Engineering 5-flourouracil and leucovorin-loaded vesicular systems for possible colon specific delivery: In vitro evaluation and real time cell assay against HCT-116 colon cell lines

5-flourouracil (5-FU) is typically modulated with leucovorin (LEU) in clinical practice to improve clinical efficacy and patient survival rates. However, this combination has undesirable side effects and makes 5-FU more toxic. Hence, integrating a vesicular system (proniosomes) with another delivery vehicle may improve drug targeting, while resolving the aforementioned drawbacks. This study aimed to engineer 5-FU/LEU proniosomes for possible delivery to the colon. The modified slurry approach was used to create drug-loaded proniosomes (150 mg/9 g of carrier) using both water-soluble (dextrin (DEX) and lactose (LAC)) and insoluble (Neusilin FH2 (NEU)) carriers. The powdered formulations were filled into Eudragit S100 (10 %)-coated capsules or Eudragit FS 30D capsules for enteric- or colon-specific delivery. In vitro evaluations (flow properties, powder X-ray diffractometry (XRD) analysis, particle size analysis, entrapment efficiency, drug release, scanning electron microscopy (SEM), polydispersity index, Fourier transform infrared spectroscopy (FTIR), and stability studies) were performed on the formulations. An in vitro cytotoxicity test [real-time cell assay (RTCA)] against HCT-116 colon cancer cell lines was performed using the optimized formulation. In vitro evaluations showed that the nanoparticles had good physicochemical properties. RTCA studies showed sustained cell death with the formulations compared to the pure drug and placebo. The sequential drug release of the colon-targeted capsules containing 5-FU and LEU- loaded proniosomes showed negligible drug release in SGF (pH 1.2) and phosphate buffer solution (pH 6.8) (approximately 11 %) but profound drug release (>80 %) at pH 7.4. Drug-loaded proniosomes engineered for colon targeting (Eudragit S100 (10 %) capsules or Eudragit FS 30D capsules) showed good colon-specific targeting and favorable in vitro cytotoxicity profiles.

Developing and Evaluating a Novel Drug Delivery System, Calcium-Alginate Beads loaded with Valsartan

Valsartan is one of the most common drugs used by chronic patients in the management of hypertension, heart failure, and diabetic nephropathy. This present study was conducted with the aim of formulating a long-acting pharmaceutical form by preparing millimeter dimensions’ solid polymeric beads using the Ionotropic Gelation technique by using the polymer “Alginate Sodium” (SA), and Calcium Chloride CaCl2 as a cross-linking agent. Prepared valsartan beads succeeded in the possibility of decreasing dose administration and therefore, reduced immediate release side effects of conventional forms of Valsartan. Valsartan beads were studied using different concentrations of Sodium Alginate and Calcium Chloride to select the optimal formula and then were compared with locally marketed film-coated tables containing Valsartan. The formula (SA 3%, CaCl2 10%) was chosen after conducting several physiochemical tests such as shape and dimensions, swelling index, entrapment efficiency, in vitro drug release, and FTIR. FTIR test showed no chemical bonding between Valsartan and other excipients. Selected beads achieved a high percentage of swelling in phosphate buffer solution pH=6.8. Entrapment efficiency was also high at about 80%. Prepared beads followed the Korsmeyer-Peppas release mechanism, and eventually obtained extended-release beads which slowed drug release for 24h, Compared with the film-coated tablets, the in vitro release of valsartan expired after only one hour.

Electronic Structures of Passive Film Formed on Ti and Cr in a Phosphate Buffer Solution of pH 7

The electronic structures, including the semiconductive properties, of the passive films formed on Cr and Ti in a phosphate buffer solution of pH 7 were evaluated using photoelectrochemical response, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy (XPS). Based on the results, electronic band structure models of the passive films were proposed: the passive films on Cr consisted of an inner p-type oxide layer with a band gap energy, E g, of 3.6 eV and an outer p-type hydroxide layer with E g of 2.5 eV whereas those on Ti consisted of an inner n-type oxide layer with E g of 3.2 eV and an outer n-type hydroxide layer with E g of 2.5 eV. The type of semiconductor evaluated for the oxide and hydroxide layers was strongly supported by valence-band XPS, which can provide the energy difference between the Fermi energy of the underlying metal and the highest energy of the valence bands of the oxide and hydroxide layers in the passive films.

Multipurpose arrowroot starch films with anthocyanin-rich grape pomace extract: Color migration for food simulants and monitoring the freshness of fish meat

Extraction of anthocyanins from grape pomace, is a way of valuing these abundant by-products with low added value. Its integration into films may allow it to be used in bioactive packaging, which creates new color and solubility properties for food and smart food packaging which tracks the freshness of fish. Films of arrowroot starch added with different concentrations of grape pomace extract (GPE) were flexible to handle, reddish and presented a high content of anthocyanins. The water vapor permeability increased by 17 %, while the tensile strength of arrowroot starch film decreased by 79 % with the addition of 40 % GPE. The addition of GPE increased the solubility of the starch film in aqueous and lipid food simulants by 121 and 119 %. The GPE pigment preferentially migrated to the aqueous simulant due to the hydrophilic nature of anthocyanins and starch. The GPE film showed distinguishable color changes in different pH buffer solutions from pink at pH 2 to light blue at pH 7 and slightly yellowish green at pH 10. When the composite films were monitored for fish meat freshness, the change in color of the film from reddish pink to slightly green after 96 h of storage at 25 °C was evident.

Ultrasensitive ECL immunosensor for trenbolone detection based on double-assisted signal amplification strategy of Nb2O5-decorated TiO2 nanorods and Co3O4-Co3(PO4)2 nanosheets

Trenbolone (TB) is used for treating malnutrition in livestock and increasing their muscle mass. However, its excessive intake can lead to metabolic and reproductive disorders in animals. In addition, it causes adverse effects in humans even at very low concentrations. Herein, an innovative electrochemiluminescence (ECL) immunosensor based on a double-assisted signal amplification strategy has been proposed for the sensitive detection of TB. Nb2O5-decorated TiO2 nanorods, with a large surface area, good biocompatibility, and excellent catalytic properties, were used as the substrates for the effective loading of TB antibodies. In addition, Co3O4-Co3(PO4)2 nanosheets, used as labels, improved the ECL signals and were used to incorporate TB antigens for designing competitive ECL immunosensors. Various experimental factors, such as the pH of the phosphate buffer solution, concentration of the co-reactant, and time of incubation, were examined. The proposed ECL immunosensor exhibited high sensitivity, good repeatability, and high stability for TB concentration and was successfully implemented for the analysis of real water samples. Under optimal conditions, the proposed immunosensor responded linearly to relevant concentrations of TB from 1.0 × 10−3 to 1.0 × 103 ng/mL, with a detection limit of 0.39 × 10−3 ng/mL (S/N = 3). Notably, this study fabricated a simple and ultrasensitive TB detection system with novelty of practical application in environmental monitoring.

Overlooking pH decrease induced by ATP (or ATP-2Na) results in false positive response of rhodamine spirolactam derivatives to millimolar ATP

An outstanding fluorescent probe for adenosine 5′-triphosphate (ATP) in the millimolar range will shed deep light on the physiological role of ATP. Many fluorescentprobes based on rhodamine spirolactam derivatives have been developed for this purpose and claimed to detect millimolar ATP excellently, where ATP or adenosine 5′-triphosphate disodium salt (ATP-2Na) is employed to examine their response to ATP. However, in this work, it was found that both millimolar ATP and ATP-2Na could significantly decrease the pH of the common buffer solution even for several units. Considering the dependence of the rhodamine spirolactam fluorescence on pH, a series of rhodamine spirolactam-based probes was synthesized to investigate their fluorescence response to pH and ATP-2Na. The results demonstrated that the fluorescence response of the probes to millimolar ATP-2Na indeed resulted from both ATP-2Na itself and the pH decrease induced by ATP-2Na. Furthermore, it was evidenced that acidic pH was crucial for the probes to produce fluorescence response to millimolar ATP-2Na itself, and the rhodamine spirolactam-based probes would show poor sensitivity to millimolar ATP-2Na at near-natural pH. Accordingly, the previous conclusion that the rhodamine spirolactam-based probes could detect millimolar ATP excellently was almost erroneous, and might mislead the design and practice of intracellular ATP probe in the future. This work notes that attention should be paid to the physiochemical properties of the analyte and the environmental changes produced by the target analyte.

Electrochemical Sensing of Vitamin C Using Graphene/Poly-Thionine Composite Film Modified Electrode

Background: Gastric irritation and kidney problems occur due to excess ascorbic acid content, whereas the lack of ascorbic acid in the human body leads to poor wound healing, muscle degeneration, and anemia. Objectives: Herein, we report the development of an electrochemical sensor for the detection of ascorbic acid using poly-thionine/ graphene (P-Th/Gr) modified glassy carbon electrode (GCE) in 0.1 M phosphate buffer solution (PBS) (pH 7.4). Electrostatically fused graphene affixed with poly-thionine was successfully illustrated for effective voltammetric sensing of ascorbic acid. Methodology: FE-SEM indicated the blended edge of a 2D graphene sheet with a deposited thin layer of polymer, which confirmed the formation of a poly-thionine/graphene composite. The cyclic voltammetry (CV) technique was utilized for the electrochemical assay of ascorbic acid (AsA, Vitamin C). Results: With the increased concentrations of AsA, the oxidation peak current of ascorbic acid increased at 0.0 V, and the overpotential showed a decrease compared to bare GCE. The effect of scan rate on cyclic voltammograms was recorded with 500 μM of ascorbic acid from 10 mV/s to 250 mV/s, which indicated that AsA oxidation is a diffusion-controlled process on poly-thionine/ graphene-modified electrode. Conclusion: It was concluded that a poly-thionine/graphene composite-based sensor could be useful for the determination of ascorbic acid in various biological samples.

Two green and sensitive spectrofluorimetric approaches for determination of Ambroxol and guaifenesin in their single and combined pharmaceutical formulations.

Ambroxol hydrochloride (AMX) and guaifenesin (GFN) are approved drugs utilized to treat coughs through their potent mucolytic and expectorant properties. Due to their massive, combined administration in many illnesses, there is a persistent need for their concurrent estimation in different pharmaceutical formulations. Two sensitive, environmentally friendly spectrofluorimetric methods were developed. AMX was determined using the first method (I) without interference from GFN. This method depends on the quenching of Erythrosine B (EB) native fluorescence at 552 nm after excitation at 527 nm due to the formation of a non-fluorescent AMX-EB ion-pair complex in Britton-Robinson buffer (BRB) solution pH (3.5). The concentration plot is linear over the 0.25-5.0μg/mL range, with a mean percent found value of 99.74%. Method (II) depends on measuring the native fluorescence of aqueous GFN solution at two analytical wavelengths, either 300 or 600 nm, after excitation at 274 nm. Relative fluorescence intensity (RFI)-concentration plots are linear over the ranges of 0.02-0.5 and 0.1-2.0μg/ml, with mean percent found at 99.96% and 99.91% at dual wavelengths, respectively. The proposed methods were successfully applied to assay both drugs in raw materials and different single and combined pharmaceutical formulations. These methods have been thoroughly validated following International Committee on Harmonisation (ICH) guidelines. National Environmental Methods Index, Analytical Eco-Scale, and Green Analytical Procedure Index were used to prove greenness, thereby enhancing their applicability. The proposed techniques provide straightforward, precise, and cost-effective solutions for routine formulation analysis in quality control laboratories.

Determination of chromatographic conditions for quantitative assessment of active components in complex nasal spray after manufacturing and expiry date

The aim of the work is the development of chromatographic conditions, the study of the validation characteristics of the method of quantitative determination of phenylephrine hydrochloride, nitrofural, lidocaine hydrochloride and diphenhydramine hydrochloride, panthenol, povidone in the joint presence in the nasal spray by a complex method of liquid chromatography with UV detection. Evaluation of the quantitative content of active components after manufacturing and during the shelf life.
 Materials and methods. Agilent 1260 liquid chromatographs, equipped with a diode-matrix detector from the company "Agilent technologies", USA. Chromatographic columns 250×4.6 mm in size, filled with octadecylsilyl silica gel for chromatography (Zorbax StableBond SB-Aq, Agilent company), mobile phase A - phosphate buffer solution pH 7.0 - acetonitrile P (1650:350), mobile phase B – acetonitrile P; elution mode – gradient; mobile phase flow rate – 1.0 ml/min; detection wavelengths – 220 nm (for panthenol, phenylephrine, povidone, diphenhydramine) and 235 nm (for nitrofural and lidocaine).
 Results. Chromatographic separation conditions were developed for the co-presence determination of six target substances: panthenol, phenylephrine hydrochloride, nitrofural, povidone, lidocaine hydrochloride and diphenhydramine hydrochloride. The suitability of the technique for this task was confirmed by determining the validation characteristics. The methodology at the appropriate level is characterized by specificity, linearity, correctness and convergence in the range of application for panthenol (range 20.33-38.26 mg/ml, ΔZ=0.93 ≤ max ΔZ=3.20, a=0.63 max a=5.12, r = 0.9978 min r= 0.9924), phenylephrine hydrochloride (range 1,70-3,21 mg/ml, ΔZ=0.51 ≤ max ΔZ=3.20, a=0.15 max a=5.12, r = 0.9984 min r= 0.9924), nitrofural (range 0.137-0.257 mg/ml, ΔZ=0.91 ≤ max ΔZ=3.20, a=0.032 max a=5.12, r = 0.9987 min r= 0.9924) povidone (range 20,44-38,50 mg/ml, ΔZ=0.23 ≤ max ΔZ=3.20, a=2,33 max a=5.12, r = 0.9942 min r= 0.9924), lidocaine hydrochloride (range 6,80-12,81 mg/ml, ΔZ=0.34 ≤ max ΔZ=3.20, a=0.66 max a=5.12, r = 0.9988 min r= 0.9924), diphenhydramine hydrochloride (range 1,36-2,56 mg/ml, ΔZ=0.20 ≤ max ΔZ=3.20, a=0.15 max a=5.12, r = 0.9980 min r= 0.9924). There are no significant changes when stored at 25 °C for 6 months.
 Conclusions. An analytical method of quantitative determination of the component composition in an extemporaneous nasal spray by a complex method of high-performance liquid chromatography has been developed. The determined validation parameters confirm the correctness of the methodology. The chemical stability of the dosage form is observed for 6 months

Terbium Vanadate Nanowires-Based Electrochemical Sensors for Mercury Ions.

Terbium vanadate nanowires were synthesized via a facile chemical approach using sodium vanadate and terbium chloride. Morphology, structure, composition, and electrochemical characteristics of the terbium vanadate nanowires were investigated by different techniques. Terbium vanadate nanowires with single crystalline tetragonal TbVO4 phase possess smooth surface and flat tips. The length of the nanowires is longer than 5μm, and diameter is 40-100nm. Terbium vanadate nanowires modified electrode was used for trace-level mercury ions (Hg2+) detection. One well-defined stripping peak exists at - 0.34V at the terbium vanadate nanowires modified electrode in 0.1mM Hg2+ solution. Buffer solution pH value, deposition time, deposition potential, and standing time are pH = 1, 150s, - 1.5V, and 60s, respectively. Detection limit for Hg2+ detection is 0.18nM, and linear range is 0.01-100μM. The proposed terbium vanadate nanowires modified electrode exhibits significant selectivity, stability, and reproducibility toward Hg2+. The usefulness of the developed sensor based on the terbium vanadate nanowires modified electrode was verified by Hg2+ detection in real samples.

Multiwall Carbon Nanotubes/Spherical Glassy Carbon as Environmentally Friendly Adsorption Materials Utilized in Adsorptive Stripping Voltammetry for the Determination of Trace Amounts of Ga(III).

This work presents a proposal for an adsorptive stripping voltammetric (AdSV) method for gallium(III) determination at an eco-friendly multiwall carbon nanotube/spherical glassy carbon (MWCNT/SGC) electrode modified with a lead film. The operational factors influencing the sensitivity of the AdSV procedure were thoroughly investigated, and their most favorable values were chosen (0.1 mol L-1 acetate buffer solution pH = 5.6; 7 × 10-5 mol L-1 Pb(II); 2 × 10-4 mol L-1 cupferron; potential/time of lead film formation: -1.9 V/30 s; potential/time of Ga(III)-cupferron adsorption: -0.75 V/30 s). The newly developed MWCNT/SGCE has proven to be a competitive substrate to the glassy carbon electrode to create a lead film electrode, since it allows the determination of gallium in a wider range of concentrations from 3 × 10-9 to 4 × 10-7 mol L-1 with a lower limit of detection equal to 9.5 × 10-10 mol L-1. The elaborated procedure has been shown to be highly selective and insensitive to the presence of an even 100-fold excess of most of the ions commonly found in environmental waters. The MWCNT/SGC sensor, which can maintain >95% of its original response after 70 days of use, has been successfully applied for the detection of gallium in water samples with the relative standard deviation (RSD) ranging from 4.5% to 6.2% (n = 3) and recoveries in the range from 95.3% to 104.9%.

Selective Electrochemical Detection of Thymoquinone in Black Cumin Using Titanium Oxide-Modified Graphite Paste Electrode

Thymoquinone, a significant component in medicine and the spice industry due to its potent antioxidant properties, is the focus of this paper. The development of a titanium oxide-modified graphite paste electrode is presented for the detection of thymoquinone in black cumin. The electrochemical characteristics of the thymoquinone molecule were explored in a 0.1 M phosphate buffer solution of pH of 6. The modified graphite paste electrode exhibits excellent linearity across the concentration range of 0.1-200 [Formula: see text]M with limit of detection is 0.02 [Formula: see text]M. The developed electrode exhibits commendable repeatability, reproducibility and exceptional sensitivity towards thymoquinone. The separation of various concentrations of thymoquinone samples such as Mousumi, Priya Gold, Sunrise and DNV using Principal Component Analysis (PCA) with the Separability Index (SI) of 67.89 utilized to differentiate between different thymoquinone concentrations.

A Retrospective Comparison of Onabotulinum Toxin A and Incobotulinum Toxin A in Terms of Efficacy, Tolerability, Duration of Effect, and Pain on Injection Administration Site for the Treatment of Chronic Migraine.

Background Onabotulinum toxin A (OnA) is a well-tolerated and effective treatment for chronic migraine (CM). However, based on research indications that incobotulinum toxin A (InA) would be equally effective, a VeteransHealth Administration medical center mandated a two-year trial of InA as a more cost-effective alternative to OnA. Although InA is used for many similar indications as OnA, it is not Food and Drug Administration-approved for treating CM, and complications occurred in several patients with CM following this treatment change. We conducted this retrospective analysis to evaluate differences in the efficacy of OnA and InA and identify the reasons for the adverse effects of InA in some of these patients. Methods We performed a retrospective review of 42 patients who had been effectively treated with OnA and were then switched to InA. The differences between treatment responses to OnA and InA were assessed through the evaluation of pain on injection, number of headache days, and duration of action. Patients received injections at 10- to 13-week intervals. Those who reported severe pain on injection of InA were switched back to OnA. Results Severe burning pain on InA injection was reported by 38% of patients (nine males and seven females, i.e., a total of 16 patients out of 42 patients). One male patient reported the same degree of pain fromboth InA and OnA injections. A total of 66.7% of women with obesity and 83.3% of men with obesity or diabetes experienced severe pain on injection. Neither migraine suppression nor the duration of effect was significantly different between OnA and InA. Conclusions OnA isbetter toleratedthan InA in the treatment of CM. InA appears to effectively suppress migraines, but some patients complain of a severe localized burning sensation during the injections. Some of these patients, all of whom were previously treated with OnA, requested to switch back to OnA. This suggested that InA is not equivalent to OnA in terms of tolerability and effectiveness.The present studyfound 2.38% of patients experienced an insufficient duration of effect withInA, and none withOnA. However, these lower rates may, in part, be due to variability in injection intervals in this sample, which could be because of scheduling considerations at the Harry S. Truman Veterans Health Administration Medical Center. In cases where OnA fails because of the development of antibodies, it might be reasonable to switch to InA treatment. Reformulation of InA with a pH-buffered solution may eliminate the difference in pain on injection. InA would then be a good alternative to OnA for treating CM.

Simultaneous Analysis of Dopamine and Ascorbic Acid Using Polymelamine/Gold Nanoparticle-Modified Carbon Paste Electrode

Modification of electrode using polymelamine (PM) and gold nanoparticles (AuNPs) has been successfully developed via electropolymerization and electrodeposition onto carbon paste electrode (CPE) using cyclic voltammetry (CV) technique. The modified electrode (AuNPs/PM/CPE) was applied as voltammetry sensors in a simultaneous of dopamine (DA) and ascorbic acid (AA). AuNPs/PM/CPE presented an effective surface area 5 times wider than CPE and demonstrated good electrocatalytic performance in the oxidation of DA and AA in 0.1 M phosphate buffer solution (pH 3) with a scan rate of 100 mV s−1. The differential pulse voltammetry (DPV) technique was chosen as the best method for separating potential peaks of DA and AA. The linear response for determining DA and AA using the DPV technique produced a concentration range of 0.1–13 and 0.4–12 µM with coefficient linearity of 0.9999 and 0.9997, the limit of detection of 0.1405 and 0.2187 µM, the accuracy of 89.62–109.16%, and 83.63–105.08%, and the precision of 0.017–0.701% and 0.066–0.626%, respectively. In addition, this electrode was applied in a real sample of infant urine with a concentration of 1 µM by spike method and found 98.86 and 98.28% as percent recovery of DA and AA, respectively.

Unveiling The Multifunction of Beaded Stream‐Like Co9Se8 Catalysts for Water Splitting, Reactive Oxygen Species Scavenging, and Hydrogen Anti‐Inflammation

AbstractThe electrocatalytic preparation of hydrogen at different pH values not only achieves excellent device performance but also promotes the application of reactive oxygen species (ROS) clearance and hydrogen anti‐inflammation. However, it is difficult to develop materials that simultaneously achieve these excellent properties. Herein, the preparation of beaded necklace‐like Co9Se8 microspheres using a general and facile synthetic strategy is reported. The Co9Se8‐modified electrode has three applications: efficient water splitting for enhanced performance, ROS scavenging, and hydrogen anti‐inflammatory activity. Experiments, high‐angle‐annular‐dark‐field scanning transmission electron microscopy, and density functional theory calculations indicate that the reconstructed Co(OH)2 plays a vital role in the oxygen evolution reaction and that the transition from *O to *OOH is the actual rate‐determining step. The Co9Se8 material, with its unique beaded necklace‐like structure, exhibits exceptional hydrogen production capabilities in phosphate buffer solution (pH 7.4). In particular, hydrogen produce under neutral conditions can effectively reduce ROS levels and significantly inhibit inflammation‐related pathological processes, playing a unique antioxidant and anti‐inflammatory role at the cellular level. The obtained results indicate that the as‐synthesized Co9Se8 is more suitable for water splitting, ROS scavenging, and hydrogen anti‐inflammatory applications, outperforming other transition metal electrodes and rendering practical industrial and clinical applications.

Intelligent double-layer films based on gellan gum/mica nanosheets/anthocyanin/konjac glucomannan/carrageenan for food real-time freshness monitoring

In this work, double-layer intelligent films were designed and synthesized based on Broussonetia papyrifera fruit anthocyanin (BPFA), mica nanosheets (MN), konjac glucomannan (KG), carrageenan (CA) and gellan gum (GG) using layer-by-layer casting strategy for real-time and in situ food freshness monitoring. The KG/CA/BPFA layer served as the indicator layer, while the GG/MN layer acted as the protective outer layer. It was observed that the water vapor permeability value of the GG-MN/KG-CA-BPFA double-layer film was reduced by 4.7 times, and the tensile strength was increased by 4.1 times compared with the GG film, which could be related to the reinforcing effect and proper barrier property of MN. Notably, the double-layer film blocked most of UV-light and oxygen, and its water contact angle reached 102.4° ± 1.18°. In particular, the films showed favorable visually detectable colorimetric responses to different pH buffer solutions and volatile ammonia. More importantly, visual assessment using shrimps as test specimens demonstrated distinct color alteration from red to blue-grey on spoilage. The color change of the film was also highly correlated with TVB-N (R2 = 0.964) and pH (R2 = 0.999). In conclusion, the newly designed double-layer film exhibited excellent performance, which guides an innovative approach for advanced food-packing material development.

<i>In-vitro</i> dissolution profiles comparison for various drugs with active ingredient Febuxostat commercially available on the Russian market

Introduction. Gout treatment drugs are widely represented on the pharmaceutical market of the Russian Federation, including those with INN febuxostat. These drugs differ in excipients composition, in the dosage form (tablets and capsules) and production technology. The Dissolution Kinetics Test was chosen to assess the rate and extent of active ingredient release for drugs with INN febuxostat for different manufacturers as in vitro test dissolution allows to suggest the release from the dosage form in vivo. The rate and percent of active substance release are factors that have a direct impact on the bioavailability of drugs. Drug release was studied in a phosphate buffer solution pH 6.8, sampling was carried out at time points 0 min, 5 min, 10 min, 15 min, 20 min, 30 and 45 min. The analysis of the obtained solutions was carried out using the UV spectrophotometry method at a wavelength of 317 nm. The comparison of dissolution profiles was carried out in accordance with the requirements of Decision of the Council of the Eurasian Economic Commission dated November 3, 2016 N 85 "On approval of the Rules for conducting bioequivalence studies of medicinal products within the framework of the Eurasian Economic Union". The purpose of the study. The purpose of this study was to compare the kinetics of the release of the active substance febuxostat from drugs registered in the territory of the Russian Federation in the form of tablets and capsules. Materials and methods. Drug release studies were performed using the Sotax dissolution tester AT Xtend, Switzerland. Each drug was analyzed in 12 repetitions in a pH 6.8 phosphate buffer dissolution medium, on a "Paddle apparatus", special sinkers were used for capsule dosage forms. The selected samples were analyzed on a Shimadzu UV 1800 UV spectrophotometer, Japan, at a wavelength of 317 nm. Results. Dissolution profile studies for three drugs with the active substance febuxostat were conducted in a phosphate buffer solution pH 6,8. For the studied drugs, the release of febuxostat was observed to be more than 85 % at 15 minutes. The release profiles can be recognized as equivalent without further mathematical processing. Conclusion. Based on the results of dissolution profile studies, no differences were found in dissolution profiles of febuxostat from drugs with different dosage forms (tablets and capsules).

Electrochemical silica removal from carbon nanotube surfaces: Energy consumption and removal mechanisms

Inorganic fouling, or scaling, is a major challenge for engineered systems exposed to aqueous environments, particularly in water treatment, desalination, or thermal systems where the high salinity and temperature conditions favor surface scaling. Silica, in particular, is hard to remove once a scaling layer forms on the surface. Current scaling mitigation strategies include the addition of antiscalants, physical cleaning by flushing or backwashing, and pretreatment of the feed water. These mitigation strategies increase operation costs due to increased chemical use and system downtime, as well increase the complexity of the process. In this work, we investigated the ability of carbon nanotube (CNT) coatings to disperse silica from the surface via electrochemical reactions, providing a chemical-free approach to scaling control. Silica scaling was induced and then dispersed from CNT coupons upon the application of a potential difference across the experimental set up, with the CNT coupon acting as a cathode or anode. Scale removal was measured using optical coherence tomography at different applied current densities. In this study, a cathodic current of 2.5 A/m2 was found to achieve the highest silica removal: > 75% after 30 min. Control experiments conducted using pH-buffered solutions and pH-insensitive gypsum as the scaling mineral suggest that silica dispersion from the CNT surface was due to a combination of gas evolution and interfacial pH change. These results provide a better understanding of the potential of using electrochemical coatings for the removal of inorganic fouling from surfaces.